FIRST OFF!!! Before anyone jumps down my throat about this being a useless modification… Please let me explain the reasons for my madness. Starting with an LPFP (low pressure fuel pump) upgrade might seem like an unusual approach to modifying the FK8/FL5/DE5 fuel system. But, as many of you know, the stock fuel system in these cars limits power output on pump gas and restricts ethanol levels with a Flex Fuel setup.
- The high-pressure fuel pump (HPFP) on the FK8 is a critical component. It works in tandem with the injectors and the low-pressure fuel pump (lifter pump) inside your gas tank to deliver fuel. However, the HPFP can be a bottleneck for tuned FK8s. It is often considered the biggest limitation to increasing power on these cars. Even on the factory tune, the pump is near its capacity.
Traditionally, people chasing significant power gains or running higher ethanol concentrations replace their stock HPFP with an aftermarket one (like XDI, Hondata, Full Race, or even S.E.S) to increase fuel delivery and cope with increased demand. However, I’m not looking to spend a lot of money and I’m not chasing big power gains. With Wunderladen Racing releasing a full plug-and-play LPFP option for our cars, I figured spending $200 to see if it could help add additional support and stabilize fuel duty/demand was a worthwhile investment, especially with all the fuel pump recalls out there. This would also give me peace of mind when asking the most from my car. My goal was very modest: I simply wanted to see if adding an aftermarket LPFP would allow me to safely increase my ethanol content past the E20 limit recommended by my current Phearable.net tune, potentially reaching E30 levels.
Here’s the idea: By swapping for an aftermarket low-pressure fuel pump, I hypothesize that it might be possible to safely increase the ethanol content beyond E20. This could be achieved without exceeding the HPFP duty cycle, which we can monitor using Hondata. Ultimately, I’m looking to see if I can safely run a higher ethanol blend, closer to E30, to better benefit from its potential for improved engine cooling, all while staying within the safe operating limits of the stock fuel system no matter the weather conditions, or abuse the car is going through.
- You can read high-pressure fuel rail pressure with any OBD2 scanner, as well as with tools like Hondata and KTuner. On a normal tune, the target pressure is 200 bars at full load, and ideally, it should stay within 5 bars of this commanded pressure. While not ideal, drops of up to 10-15 bars from the commanded pressure (DIFPCMD) are acceptable. Any larger pressure drops risk putting the ECU into protection mode.
Going into this, I wasn’t expecting a massive improvement or a significant reduction in stress on the entire fuel system from just adding a low-pressure fuel pump (LPFP). Realistically, substantial upgrades like high-pressure fuel pumps, injectors, or a complete fuel system overhaul would be necessary to improve flow rate, lower duty cycle, handle E30+ effectively, and ensure the fuel system keeps up with what the ECU commands.
However, I thought there might be a chance that a stronger LPFP could still offer some benefit by alleviating some burden on the overall fuel system. After all, my goal wasn’t chasing horsepower; I was primarily interested in the potential cooling advantages of E85 since overheating is a known achilles heel for these cars.
Due to the inexpensive cost of a low-pressure fuel pump (LPFP) compared to other fuel system upgrades for these cars, I set out to conduct my own personal experiment. By analyzing data logs, I aimed to determine if an aftermarket LPFP would enable a slight increase in usable ethanol content without adding any additional strain to the fuel system. Additionally, I wanted to investigate whether a LPFP upgrade becomes truly necessary only when paired with a high-pressure fuel pump (HPFP) upgrade. While the impact might be minimal, the LPFP upgrade should surely offer a potential benefit: improved peace of mind regarding fuel system capabilities no matter how hard I’m being on the car or the weather.
As many FK8/FL5/DE5 owners are aware, the stock fuel system becomes the bottleneck for achieving reliable, higher horsepower outputs. Typically, safely exceeding ~375-400 whp (wheel horsepower) necessitates upgrading to an aftermarket high-pressure fuel pump (HPFP) and potentially injectors for safe operation. This is particularly critical when utilizing ethanol blends (flex-fuel). Without these upgrades, E30 or higher ethanol concentrations are generally considered unsafe or at the very limit of fueling due to limitations in fuel delivery and a narrow margin for the safety of the engine.
Basic breakdown of E85.
When you switch from gasoline to E85, which is a blend of 85% ethanol and 15% gasoline, your engine will require a significantly larger volume of fuel. Ethanol contains about 34% less energy per unit volume compared to gasoline. Therefore, to produce the same amount of power, an engine will typically require up to 30-40% more E85 than gasoline. This increase in fuel volume necessitates upgrades to the fuel system, including a higher capacity fuel pump and larger injectors, to handle the additional flow rate required by E85. The exact amount may vary depending on the specific engine and its tuning.
Other great benefits of E85 include:
- E85 has an octane rating of 100 to 105, which is 9 to 14 points higher than the 91 octane premium fuel found in many stations. This allows for more aggressive timing curves in the tune, and more boost, which leads to more power. It also allows you to run a higher compression ratio (if you’re building a motor)
- Ethanol absorbs over twice as much heat during combustion as gasoline does, which makes it a much more efficient cooling agent than gas.
- Engines burning ethanol leave fewer carbon deposits on valves and pistons. The exhaust actually smells better, too.
FK8/FL5/DE5 and E85 Compatibility
It’s clear that with the FK8 and FL5 models, despite upgrading injectors and high-performance HPFPs (high-pressure fuel pumps), ~E50-E60 is generally the upper limit, and that’s with substantial modifications to the fuel system. Some complete fuel systems claim that you can run full E85; however, the performance gains aren’t substantial enough to offset the added stress put on the whole system. Most of the time, the optimal choice is to opt for reliable solutions like the Hondata fuel system, the XDI high-pressure fuel pump, or even the Full Race HPFP. Typically, E40 is an achievable number when running either of those upgrades and/or aftermarket injectors (either FK8TD, JSR, or Hondata). If you’re on a completely stock fuel system, then it really isn’t advisable to try running anything above E20-25 because there are many inconsistencies in OEM fuel pumps, and for some reason, not all FK8 fuel systems are created equal, which can’t be explained.
What I mean by this is that a tuner might be able to tune one car with a stock fuel system to run E25-E30, but then the next car they tune with a stock fuel system might struggle to safely run even E25. No one has been able to pinpoint what causes this anomaly, and while the temptation to run a tune with E25 and above may sound alluring because of the big power gain potential, it’s widely advised not to run above E20-E25 without having some sort of fuel modifications/upgrades or getting a custom tune from someone who is very experienced with the Bosch ECU. Make no mistake, this is not your “golden era” Honda ECU, and just because someone is good at tuning a golden era Honda, does not mean they can safely and reliably tune an FK8/FL5/DE5. (I know that’s a hard pill to swallow for some)
Brace yourselves because what I’m about to tell you might just shatter your reality. I’m aware you’ve likely been bombarded with claims from all those so-called experts and tuners online who brag about running high levels of ethanol on an unmodified fuel system like it’s some kind of miracle. Well, let’s dive into the hard truth they won’t tell you. Let me tell you about a friend of mine who had his FK8 tuned by a super reputable tuner in Southern California (Inland Empire to be exact), and he even drove all the way down from Vegas to have this man bless his car. He ended up leaving the dyno session with 393 HP and 411 TQ, to the wheels, tuned on E40, on a Mustang dyno (very good numbers!), and ZERO fuel modifications! A few days later, after returning to Vegas, he hit me up saying that his car was hiccuping and dipping in power during 3rd and 4th gear pulls on the freeway.
Because he was running Hondata, he was able to record data logs. These logs revealed that with an E40 blend, the fuel pump duty cycle ran at 100% for multiple seconds (4-5 seconds) throughout both 3rd and 4th gear pulls, causing a big drop in fuel pressure vs command. Basically, the fuel system couldn’t keep up with the demand the ECU was asking for. While for these cars, it’s somewhat normal for the fuel pump duty cycle to spike to 100% for about a second as the boost quickly ramps up, it should then quickly settle to around 85-90% to be considered a safe tune. He noticed that lowering the blend to E30 solved the hiccuping and power drop. To further test his hypothesis, he logged additional pulls on the freeway in both 3rd and 4th gears. With the E30 blend, the fuel pump duty cycle never exceeded 93%. Arguably, 93% fuel pump duty isn’t the best either, especially when for a sustained amount of time. but it was a hell of a lot better than being at 100% for multiple seconds. Generally, a tuner will strive to stay in the 85%-90% fuel pump duty range.
This is all clearly evident in the data logs he sent me. Notably, the car was tuned in December (when temperatures were low) and the data logging was done later in the evening, with temperatures in the 40s Fahrenheit, which is most likely why the car was able to run E30 at only a 93% fuel pump duty level. It’s also worth mentioning that hotter weather can increase the fuel pump duty cycle, especially when using E30 on a stock fuel system. This could potentially reach unsafe levels under high engine load, spiking the duty to 95% and up. Which, in my opinion, is just too risky, especially if you’re tracking the car like that.
A car’s fuel pump duty will be higher during hotter months. Here’s why:
- Fuel expands in heat: Gasoline expands when it’s hot, which means it takes up more space. To maintain the correct fuel-to-air ratio, the fuel pump needs to work harder to deliver the appropriate amount of fuel to the engine. However, modern engines use Mass Air Flow (MAF) sensors to measure incoming air. The Engine Control Unit (ECU) adjusts fuel delivery based on the air mass, not volume. So, while the pump might deliver slightly more fuel due to expansion, the ECU compensates to maintain the proper air-fuel ratio. However, depending on what your tuner has adjusted in the tune itself, this could alter the safeguard built-in from the factory.
- Increased engine temperature: Hot weather leads to higher engine temperatures, which can cause the fuel to evaporate more quickly. The fuel pump needs to work harder to maintain the correct fuel pressure and flow rate.
- Air conditioning load: During hot months, the air conditioning system is working hard, which puts an additional load on the engine. The fuel pump needs to deliver more fuel to the engine to compensate for this increased load.
- Lower fuel density: Fuel density decreases with temperature, which means the fuel pump needs to work harder to deliver the same amount of energy to the engine.
Overall, the fuel pump works harder during hotter months to maintain the correct fuel flow and pressure. These factors are especially relevant when running elevated ethanol levels. As you read earlier, ethanol itself requires more fuel delivery to achieve the same energy output as gasoline. Combining hotter weather with elevated ethanol levels further increases the workload on the pump and can lead to increased wear and tear, particularly when the fuel system is already operating at near capacity (as our cars do! Even from the factory, the FK8/FL5 fuel system is pretty much maxed out just running regular 91/93 octane without increasing the ethanol levels above E10).
Now, of course, many, MANY, MAAAAAANY variables could affect his tune and cause his car to act this way, and I’m not even going to get into all that. But the fact is, it is very tricky to get our cars to run safely and reliably while using a completely stock fuel system with anything above E30. Just because he was able to get his car tuned on an E40 blend and briefly make really good HP and TQ numbers doesn’t mean it was sustainable, especially for a daily driver who has to use all sorts of different fuel brands, mixtures, wants to drive in all types of climates safely, and occasionally use the car on the road course in extremely rigorous conditions. For me, there just isn’t enough margin for safety in running E40 on a stock fuel system. I also wanted to highlight that he did in fact reach out to the tuner about his car not running well on E40. At first, they responded to his DM right away and instructed him to email them… Unfortunately, they never responded to his email. He tried to DM them again but was ghosted after that. Remember, be VERY careful about who you let tune your car.
Here’s my personal story about flex fuel and why I originally decided to do this experiment.
In November 2022, I installed a Penguin Tech Racing flex fuel kit (with upgraded PTFE line) and Hondata Flex Fuel basemap on my car, naively believing the internet hype about safely running E30+ on a stock fuel system (as long as it didn’t go above E40). I filled up with E35; the car initially felt great. It ran well and pulled hard when getting on it, especially during the cool winter evenings (40s-50s Fahrenheit).
But here’s the catch: My car wasn’t anywhere near stock… In fact, I had even more modifications than my buddy who was tuned on E40!
- 27won intercooler
- 27won boost tubes
- PRL HVI
- PRL TI inlet pipe
- RV6 catted downpipe
- Tomei Exhaust
- NGK Ruthenium spark plugs
- Acuity reverse flow hoses
- Koyo radiator
- J’s grille
- First molding hood.
AND, to further support the increased fuel flow demand, I had even previously installed a JSR-modified high-pressure fuel line.
If you’re interested in reading my write-up on how to install the high-pressure fuel line, click the link below.
With the car running well on the Hondata basemap with all my mods, I felt confident using the E30-E35 blend thanks to the modified high-pressure fuel line. Data suggests these modified lines can reduce fuel injector duty by 10%, delivering more fuel to the injector tip. However, it’s important to remember that E30-E35 still represents a significant increase in ethanol content for a stock system. The modified line and conservative Hondata map might have been what allowed me to run this blend safely around town while doing a hard pull every now and then, but it’s not a guaranteed safe practice for everyone. And as you’ll soon read, my car did not fare well when on the track with air temps in the 90s (Fahrenheit).
After installing the Hondata basemap tune, it took me about six months to make it back to the track. But in May 2023, I finally made my way back down to Buttonwillow to see if running an E35 blend (along with all my other mods) would help keep the car cooler and allow for more than a couple of laps before getting hot. As you can read by clicking the link below, the car ran decently; I was even able to get deeper into the “SUB2’s” – 1:58 to be exact.
Despite initial promise, the overheating problems persisted. To my surprise, the car also threw a check engine light (CEL) and sputtered during afternoon sessions. The CEL code pointed to the secondary O2 sensor, which I thought the flex fuel basemap tune had deactivated. Additionally, the car hiccuped at higher RPMs, likely a combination of the E35 and the fuel system not being able to support that, scorching afternoon temperatures (reaching into the 90s Fahrenheit), and running the car a few ticks above the normal mark on the temp gauge. To address these issues, I diluted the ethanol content to a safer ~E27 mix, which resolved the problems for the rest of the day.
This experience served as a wake-up call. I realized I’d been taking a risk running E35, particularly under the demanding track conditions. It became evident that my only fuel system modification—a modified high-pressure fuel line—wasn’t sufficient for safe E35 operation at the track, especially with just a basemap tune.
After the Buttonwillow event, I limited myself to E30 or lower ethanol blends. To further assess performance, I even conducted my own research by gathering a data log via Hondata. This log focused on how the car behaved with E26 during summer conditions (96°F) with the AC running, all while still on the basemap tune. (you will see this data log later on in the article)
I knew that running a basemap wasn’t ideal, but my friends’ less-than-optimal experiences with a “reputable” tuner left me hesitant. After researching for months, I finally opted to go with a Phearable.net Stage 3, Off-The-Shelf (OTS) tune for my FK8 Civic. Their strong reputation within the community, positive associations with respected YouTube channels (such as LHT Performance & AHC Garage), and data-logging review service for optimal performance and safety solidified my choice.
During my consultation with John Vega at Phearable.net, I explained my aggressive track driving style and the overheating issues. I also mentioned that I wasn’t focused on making maximum power, but rather on keeping the car as safe and reliable as possible. He assured me his tune would optimize performance and safety for those conditions. However, due to my limited fuel system upgrades, he advised against exceeding E20. This was a setback, as my goal for the tune was to leverage flex-fuel and the potential cooling benefits of E85. Ultimately, I prioritized safe performance and opted for the recommended E20 limit due to my lack of major supporting fuel system modifications.
The Phearable.net OTS tune delivered impressive results. Despite using E20, my “butt dyno” indicated a similar performance to the E35 with the Hondata basemap. This translated into several wins:
- Safety First: Peace of mind knowing the tune was optimized for my car, even under heavy abuse.
- Fuel Efficiency: Significantly less E85 was needed to achieve the same power, reducing strain on the fuel system.
- Multi-Tune Versatility: The tune offered multiple power levels conveniently selectable through the steering wheel cruise control buttons – a fantastic feature!
The downside was that E20 is only about 10% higher than what comes out of the pump already, and I wasn’t really gaining any added cooling benefits normally associated with E85 fuel. You see, because of the EPA’s Renewable Fuel Standard policy, years ago, most gas stations had to start selling gas that had a 10% ethanol blend, commonly known as E10, to help reduce the overall carbon footprint because less carbon is released during combustion. Ethanol adds oxygen to the fuel mixture, which helps to burn the gasoline more completely, reducing emissions of harmful gases like carbon monoxide. It also helps reduce our dependence on oil, as ethanol is produced from plants like corn or sugarcane, which are renewable.
This, of course, all makes perfect sense from an environmental standpoint, but it also distracts us from the fact that oil companies are essentially “cutting” their product. If “Drug Dealing 101” has taught me anything, it’s that cutting your product is a great way to increase profits. Just as laxatives, laundry detergents, boric acid, and creatine are “cut” into cocaine for increased profit, so too is ethanol much cheaper than the pure, uncut product needed to make petroleum gasoline. To prevent this from turning into a rant, I just want to mention that it’s no wonder big corporations are so involved in government and politics.
Twenty-seven (ish) paragraphs later, and here it is… finally, the reason(s) I’m installing this. Due to the recent expansion of Honda’s recall for fuel pumps on our cars (of which mine still doesn’t fall), the slender thread of hope that I could possibly increase my ethanol content slightly to near E30 levels while running the Phearable.net OTS tune, allowing me to gain a bit more cooling. Last but certainly not least, my friends over at Wunderlanden Racing developed a truly plug-and-play fuel pump installation kit. Because of these reasons, I decided to embark on my own little science experiment.
Knowing that the Phearable tune is good for up to E40, as long as you are using an upgraded HPFP, injectors, or the Hondata complete fuel system, I was interested in conducting my own experiment. I wanted to see if by swapping to a 340 LPH (liters per hour) low-pressure fuel pump and my only other fuel system modification, the modified high-pressure fuel line, I could safely increase my ethanol content from the E20 level suggested by Joh Vega (Phearable) without increasing the fuel pump duty (as monitored by Hondata). If I could safely increase the amount of ethanol, then hopefully, I would be able to reap some of the added cooling benefits of E85. This theory of mine is hopelessly optimistic, and I highly doubt that simply by adding a LPFP, I will gain the ability to run that much more ethanol.
Upgrading the low-pressure fuel pump (LPFP) from the stock 160 LPH unit to AEM’s 340 LPH model aims to address two goals. Firstly, the increased output should better support the demands of running flex fuel. Secondly, it offers a proactive measure in case future fuel pump issues arise with cars from my year, even though mine isn’t currently part of the recall. Peace of mind is a priority for me.
Whew! That was a lot of reading; hopefully, it helps everyone understand a bit more about E85 and the reasoning behind this install. Now, let’s get to the fun part – the installation process itself. Wunderladen Racing actually offers a very thorough guide on their website [link to Wunderladen guide]. Feel free to check it out for a step-by-step breakdown.
Starting off; before you even begin this install, make sure your fuel tank is AT LEAST half full or below. As you can see below, everything included in the kit from Wunderladen Racing is shown (except for the instructions; I printed those myself for some reassurance that what I was instinctively doing matched the required steps).
Wunderladen Racing has chosen to base their plug-and-play kit around the widely popular and ever-reliable AEM 340 LPH E85 compatible high-flow in-tank fuel pump (PN 55-1200). I know that popular opinion among the people in the FK8 community is that the DW300C (PN 9-307-1059) is the “best” in-tank low-pressure fuel pump. But, the AEM is just as good if not better, just ask any serious enthusiasts.
Their kit includes:
- (1) AEM 340LPH ethanol-rated fuel pump
- (1) Fuel pump wiring harness (plug and play no splicing required)
- (1) Fuel pump filter
- (2) Fuel pump o-ring (only one is needed, but they provide two in case you rip/tear one from improper installation.
- (1) Evap hose clip (this is awesome because most likely you’ll break the OEM when removing your pump.)
Tools that are required. It should also be noted that I employed the use of a few different styles of picks and a plastic clip pry tool once I was elbows deep into the project.
This is the most important tool for this install. Without it, you will not be able to remove the lock ring to access/remove the fuel pump.
Because I’m a Red Label Whore, I splurged on the OEM Honda tool. But you can also use the ones available at your local auto parts store. Here is the part number for the non-Honda branded one (OEMTOOLS 24398 or equivalent)
Having the Honda tool is way cooler though!
Jumping right in, I began by removing the lower bench part of the back seat. There is one 10mm bolt that you will need to loosen. As seen below, you will need a medium/long extension to access the bolt.
Zoomed-out view for location reference.
Then, a zoomed-in view for clarity.
Once the 10mm bolt is removed (don’t worry if you lose it behind the seat, you will be able to access it once the bench is removed completely), you will now locate the two clips that secure the front part of the bench to the car and depress the clips to unlatch the seat.
In the picture below, you can see where both clips are located. Again, no tools are needed to unclip each clip; your fingers will be fine.
Here is what the bench portion looks like completely removed from the car.
Next, to gain access to the bolts on the seat backs, you will need to unscrew the latches that secure the trunk mat.
Simply lift the plastic cover with a flathead screwdriver, being careful not to scratch or damage the plastic cover.
Then, take a Phillips screwdriver and unscrew the Phillips screw that secures the whole trunk mat tie down.
Once the screw is removed, it should very easily just pop out as indicated below.
There are two of them. One on the driver’s side and one on the passenger side.
Same thing, one little Phillips screw holds it in place.
Zoomed out for reference.
With both tie-downs removed, you can now carefully pry upward on the trunk mat flap.
Be aware that two more clips secure it, so pry up gently.
We had to do all that work to access the fabric flaps on the back of the seats. This is where that clip pry tool comes into play.
There are three clips that need to be pried up on the driver’s side.
By removing those clips securing the seat fabric to the car, you can now begin to see the bolts we need to access for the removal of the seat backs.
The passenger side seat back needs to be removed first, so do not unbolt these yet. I’m just showing you where they are located once the fabric flap is lifted.
Move over to the passenger side and, using the clip pry tool, remove the two clips securing the fabric flap. Then, take a 12mm socket and begin to unbolt the seat back.
There are two more 12mm bolts on this side too.
Now with the passenger side seat back removed, you gain access to one 12mm bolt that goes into the driver’s side.
Simply remove that one bolt.
Then move over to the original two 12mm bolts we uncovered.
Rear seat completely removed.
With the rear seats removed, you now have easy access to the fuel pump access panel. There are four plastic Phillips screws that secure the panel, but they don’t fully unscrew; they simply rotate 90° to allow the head of the screw to pass through the panel.
Slightly lift the panel and unclip the wire harness underneath to allow the panel to be moved out of the way.
Below you can see the harness clip I speak of.
You will now need to disconnect the three fuel lines from the top hat.
One of them is accessed by removing this plastic clip/cover. Just simply pry it off with a flathead.
Next, use your fingers to pinch and release the clip securing the line to the fuel tank top hat.
viola.
Next, moving clockwise around, unclip the larger line with the green tabs. This one can be a bit tricky to disconnect, but just take it slow and you’ll get it.
Lastly, this is the one that you will almost certainly break the clip on, which is why Wunderladen Racing includes a new clip in their kit.
I was extremely delicate in how I removed the clip and I still broke mine.
Once all three lines are disconnected, you now need to break out the lock ring tool. Be warned, you must use a proper lock ring tool, DO NOT try to use a chisel/flathead screwdriver and hammer the ring off. You will damage it and will not be able to seal your tank back up until you get a new one.
Even with my breaker bar… FUUUUUUUU, this thing was a pain to get loosened. I felt like I was going to rip the whole fuel tank apart, but it finally broke free. It should also be noted that you should try to use some compressed air to remove the dirt and debris around the tank before you loosen it because you don’t want any of that falling into the tank or jamming up the lock ring possibly preventing it from easily loosening. Also, it may be useful to spray some WD-40 (or similar) around the ring to help ease the grip that the lock ring has on the tank.
The lock ring is now removed; you can see it sitting just above the access hole. You can also barely see in the bottom left corner that I had to use a pipe on my breaker bar to get enough leverage to loosen the lock ring. Use caution though, because I felt like the tank was moments away from breaking due to the force I was exerting on the lock ring as I tried to loosen it.
Before removing the top hat (white part), you’ll need to disconnect a hose on the underside. There’s a green tabbed connection that you can’t squeeze by hand. Here’s where the hose grip pliers come in handy. Instead of using them to grip the hose itself, compress the green tabs with the pliers to release the connection.
Below you can see that between my fingers I’m holding the line that needed to be disconnected underneath. It’s a real pain because there isn’t much slack in it.
Again, here is a closer look at the line. Again, this was the connection underneath the white top hat.
Once all four lines have been disconnected, you can pull out the fuel pump module (fuel pump basket assembly). At this point, you can rejoice because the hardest part is over. Also, the fuel pump basket will be full of gas; make sure you pour it all out before bringing it to your workbench.
Before taking apart the fuel pump basket completely, we’ll need to disconnect the wiring harness. There are two connectors: one provides power to the fuel pump, and the other is for the fuel level sensor.
Carefully unclip one connector at a time. It’s important to note which connector goes to which socket on the fuel pump top hat. This will prevent accidentally mixing them up during reassembly.
Unclip the second.
Don’t forget to take a picture or sketch of how the wires are routed before disconnecting them. This will ensure you reinstall them correctly later.
Next, you will need to unclip the external retaining ring from here.
Compressing the spring allows you the ability to easily access the external retaining ring and pop it off.
I just used a flathead screwdriver to wedge against the plastic part of the basket to gently pry, and with little force, the external retaining ring came off.
This is what the external retaining ring looks like.
Now the upper top hat can be moved out of the way enough to allow the pump to slide out of the basket.
But first, you must disconnect the blue clip.
The blue clip is very easy to unclip.
Next, there are three clips holding the pump housing into the basket.
Now the pump housing can easily be removed from the basket.
Next, unclip the pump from where it secures to the pump housing.
Viola, the pump is now removed.
YOU MUST TRANSFER THIS WHITE SPACER OVER TO THE NEW FUEL PUMP!
Do not lose this spacer. If you do not install it and try running two rubber O-rings instead, you will have a fuel-starving issue later.
O-Ring Installation:
As you can see, I’ve installed the white spacer from the original pump and one of the O-rings provided in the kit. As mentioned earlier, Wunderladen Racing includes two O-rings as a spare in case of damaging one during installation. It’s important to use only one O-ring in conjunction with the white plastic spacer for proper sealing.
Lubrication is Crucial:
Before inserting the pump back into the assembly, apply a lubricant specifically designed for O-rings to prevent any damage. This will create a smooth surface for the O-ring to slide into place and ensure a secure seal
Don’t Forget the Old O-Ring and Spacer!
During the removal of the original fuel pump (OEM pump), it’s critical to verify that both the O-ring and the white plastic spacer come out with it. Double-check the disassembled components. Ideally, you should see only one O-ring and one white spacer.
If the O-ring or spacer is missing from the removed pump, it means they’re likely stuck inside the fuel pump assembly. These components must be removed before installing the new pump.
Below is exactly what the pump should look like; O-ring lube, one rubber O-ring, and one plastic white spacer.
New Filter Installation:
The blue three-prong clip filter from the original pump (OEM) is not reusable. The new filter is designed for a one-way fit onto the new pump. Its size ensures a snug fit that prevents it from moving or detaching once the pump assembly is back in the basket. This applies to most aftermarket pumps and filters for these cars.
Bending the Aftermarket Filter:
The new filter might be longer than the original one. Don’t worry, it’s designed to bend at a 90-degree angle when reinstalling the pump assembly into the basket.
Now for the “plug and play” part. Wunderladen’s harness easily clips into the new pump.
Make sure the wires are routed neatly and avoid any areas where they could rub or snag on moving parts of the pump assembly or basket. Tucking them into designated channels or using zip ties can help keep them secure.
No worries if you’re unsure which connector goes where! To refresh your memory, here’s a quick reminder of how the plugs should be lined up. This way, you can double-check and ensure everything is connected correctly.
Reinstalling the Fuel Pump Assembly:
Great! Now that everything is reassembled, it’s time to place the basket/assembly back into the tank.
Tight Squeeze:
Be aware that reinstalling the assembly can be tricky due to tight spaces. Here’s the key step: make sure to connect the large line underneath the top hat before fully seating the assembly in the tank.
Gentle Does It:
Take your time and carefully maneuver the assembly into place. Avoid forcing anything, as this can damage components like the fuel level float.
Fuel Level Float:
Speaking of the float, keep an eye on it while reinstalling to prevent bending or breaking it. A damaged float can lead to inaccurate fuel readings on your dashboard.
Remember: Patience and a gentle touch are key here.
Once you have fully seated the assembly, you must put the lock ring on before you begin to reconnect the other three lines on top of the top hat. When you have all the lines reconnected and the fuel pump harness plug reconnected, do not put everything back together until you have tested for leaks by cycling the start button on and off a few times without starting the car (make sure you hear the fuel pump kick on and off a few times). At this point, you can also start the car if you’d like, just to double-check that everything is functioning as it should. I started the car just to make sure all was well and there were no leaks.
If everything passes inspection, with confidence, tightly secure the lock ring in place, followed by replacing the metal pump cover, and reassemble the seats along with all associated components, including the trunk mat and tie downs. Rest assured, the installation process, while not particularly challenging, does require a certain level of dedication and patience.
The major problem I ran into.
Before diving into the test results and data logs, I want to share a personal oversight. This heads-up might help you avoid a similar pitfall during your own LPFP install.
With the upgraded low-pressure fuel pump humming smoothly and the interior back together, I hit the road for a data collection drive. The goal? Validate my hypothesis: Could a stronger LPFP reduce fuel pump duty cycle enough to safely run a higher ethanol blend closer to E30?
Because my fuel level was low to ensure an easy pump removal, I made a beeline straight to a gas station knowing that I needed to fill up before heading about 30 minutes outside of town to a secluded test area where I would be free to push the car to triple-digit speeds. I pulled up to the gas station and brimmed my tank… *click, the pump shuts off and I know I’m full and ready to go.
As I got back in the car and started it, I noticed that my fuel level wasn’t rising on the dash and it seemed to be stuck at the quarter-tank mark. I pulled out of the gas station and drove down the street, anxiously, eyes glued to the fuel gauge on the dash to see if it would begin to rise… But nothing was happening! I tried to convince myself that it was just something that had to do with the fact that I had disconnected the wiring harness to the fuel pump/sending unit. I made a right turn onto Rancho and began heading north to get onto the 95 freeway. By the time I got to the Santa Fe Station (for those not local to Las Vegas, it’s a casino), the gauge had not moved, and at this point, I was thinking the worst… I was thinking, why did I even try swapping the fuel pump when my old one worked fine and I knew that I was only grasping at straws, hoping the low-pressure fuel pump would help the overall fuel system? What a waste, I just ruined my brand-new car! Then, in an attempt not to be so angry, I thought… Maybe I don’t need a fuel gauge; I never let my tank get below halfway anyway, and anytime I go to tracks in California, I would just stop every 3-4 hours of driving and refill.
Of course, this was asinine, and I just got even more furious with myself for even considering the fact that I could live with my brand-new car not having a working fuel level gauge. Really, I was just avoiding the thought of having to retake all my rear interior out, fight with that damned lock ring, disconnecting all four of the fuel lines, and finessing out that whole fuel pump assembly/basket a mere 30 minutes after just completing the whole installation.
Obviously, I was way too frustrated to take the car out and collect data on fuel pump duties. I took the next exit, turned around, and headed home. I was so over it! Nothing is worse than having just finished installing a part only to find out something was wrong and you now need to disassemble everything again just to inspect. Even worse, it was probably something I did wrong or forgot to do. On the way home, I replayed in my mind every minute of the installation process, checking off theoretical boxes of the whole process… It couldn’t have been something major because the car still functioned; it pulled hard all the way to redline, idled perfectly, and made no strange noises.
I arrived home, slammed the car into the garage, stormed into the house, and barked at Angie, “I fucked up the car.” It isn’t catastrophic – the car’s still driving fine – but I just messed it up enough to fry my nerves. I went to sleep that night. I should’ve been dreaming, but there I was, tossing in bed, haunted by the ghost of every step in the fuel pump installation. What the hell did I screw up? Could I have fried the circuitry, wrecked the fuel level float, or half-assed the fuel level sensor connection? Was there some mystic ritual I missed to reset/relearn that level sensor after I yanked its plug? Why oh why did I even bother replacing that pump!?
Upon awakening the following morning, I summoned the strength to methodically dismantle each component and carefully examine my prior installation work. With haste, I deconstructed the setup, taking solace in the familiar processes and utilizing the efficiencies I’d learned from my recent endeavor a mere 12 hours prior.
Disassembled and ready for inspection, a knot of anticipation tightened in my stomach. I took a deep breath to steady myself before the big reveal. As I lifted out the entire assembly, a wave of relief washed over me – the culprit was clear! Right there, staring me in the face, was my mistake. I hadn’t routed one of the fuel lines on the basket correctly, and it was snagging the fuel level float rod. The picture shows the culprit – the line was impeding the rod’s movement, preventing an accurate fuel level reading.
Mere hours ago, I was on the verge of exploding, my frustration boiling over. I could almost see myself driving the car straight into a wall. But somehow, I held back. What a relief! An immense wave of calm washed over me. I should really learn to control my rage. I mean, I have been working on it over the years… If this had happened 10 or so years ago, I probably would have smashed my fist into the windshield or something like that.
For what, exactly—a trivial, insignificant blunder that was effortlessly corrected within a mere sixty minutes? Oh, the rage! It’s a wildly potent emotion, that much is blindingly obvious. I’m glad I have learned over the years to curb my frustration because the two things I have learned are: One, it’s always usually a small mistake that is easily remedied, and Two, smashing things in a fit of rage only causes instant regret, especially when things are quite simple to fix.
See the difference; I didn’t even have the line correctly secured in the provision that was engineered into the basket. Honda engineers had already predicted this might happen, and it took a stupid DIYer to mess up the whole thing.
Take this piece of advice to heart and let it serve as a cautionary tale from my own hard-learned lessons. Meticulously examine every wire, and every line thrice before you dare to attempt reinstallation. Neglect this at your peril, for a single misstep could force you to dismantle everything you’ve only just painstakingly reassembled. Trust me, you want to avoid the agony and frustration of realizing you have to start all over again because of an easily preventable minute oversight.
I simply pushed the line into the guiding provision, slapped the assembly back in, reconnected everything, and started the car. Again foregoing complete reassembly just on the off chance this wasn’t the solution. My eyes locked on the fuel gauge on the dash as I started the car. It did the initial sweep and the read as the tank being full (because I had just topped it off 12 hours ago). God Bless America! it was all functioning properly and I hadn’t ruined my brand-new car after all. I then reinstalled all the rear interiors and waited for nightfall before setting out on my data-logging mission.
I postponed the data collection until nighttime, aiming to match the temperature and conditions identical to those during my initial data logging with the OEM fuel pump (the data logs that I had sent off to Phearable for review). My objective was to account for all controllable variables meticulously, thereby solidifying the credibility of my data and precluding any criticism of testing flaws.
Datalog comparisons.
In my experiment, I analyzed three sets of data logs:
- E26 Hondata Basemap data log: This log was recorded by me in the summer of 2023.
- Phearable.net review logs: These were the logs sent to Phearable.net for review of the stage 3 tune using the stock LPFP with E20 fuel in December 2023
- AEM LPFP comparison log: This log was recorded by me after installing an AEM LPFP and still utilizing the Phearable stage 3 tune. I ensured that the test conditions were as close as possible to those used for the logs sent to Phearable.net. February 2024
By comparing these logs, specifically the Phearable.net review logs vs the AEM LPFP comparison logs, I would hopefully be able to conclude if swapping for an aftermarket LPFP was beneficial or not. I feel it is also important to highlight the fact that in each one of the 3 data logs, the car had all of the same modifications done to it. The only difference was the tune, and lastly the AEM LPFP.
Below I will share with you the data logs from OEM LPFP running the Hondata flex fuel basemap at 26% ethanol (summer of 2023), the OEM LPFP running the Phearable.net Stage 3 OTS tune at 20% (December 2023), and lastly, the AEM LPFP running the same exact Phearble.net Stage 3 OTS tune at 22% (closest I could get the blend) (February 2024) and go over what my findings were.
The first graph we will discuss is the Fuel Pump parameters from the 26% blend Hondata basemap datalog MP4. Again, this was in summertime, 96 degrees Fahrenheit, with my A/C on. The goal was to stress test a bit. I also chose to have the MP4 start halfway through the datalog because the first half was just me taking off from a red light and making the turn onto the freeway. But I did leave the first half of the graph viewable just to prove I’m not hiding anything. Keep in mind that in all three scenarios, as you’ll see below, I did have the modified high-pressure fuel line installed.
Also, in case you don’t know… Each vertical dotted black line on the graph represents one second. Knowing this will help you to better understand the datalog graphs.
Here are the key takeaways from the Fuel Pump Parameter MP4 below:
- This is the Hondata flex fuel basemap tune with the car running a 25%-26% ethanol blend.
- Despite the 96-degree heat and the added stress of the A/C being on, the Fuel pump duty, for the most part, stays below 90%. with the exception of a few extremely quick spikes but none going above 93%.
- You can also see that the DFIPCMD and the actual DIFP are very close. This is mainly because the Hondata Basemaps are usually pretty conservative.
The MP4 below is still the same 26% base map datalog, but this time we are looking at the Flex Fuel parameters. I’m only showing this one so you can see the ethanol level throughout the whole pull is consistent. Plus, this one more clearly shows the “noise” or erratic nature of the fluctuating fuel pump duty beginning at 5300 RPMs through to 6200 RPMs in 4th gear.
Lastly, the Boost parameters. I only included this to show everyone what my boost levels were throughout the whole data log again to ward off any concerns about the credibility of the data log. As you can see, they basically maintain a constant 21.2-21.8 PSI with a brief jump to 22.2 PSI.
Finally, here is an MP4 showing pretty much all the (important) sensors throughout the whole log. This shows air temps, coolant temps, timing, AFR, and many more. Again, I’m only including this to be completely transparent and leave no room for naysayers.
Now, let’s move on to the datalog for the OEM low-pressure pump with the Phearable.net stage 3 OTS tune. This is the one that I sent to Phearable.net for review. Again, just a reminder, this is with all the same modifications listed above (including the modified high-pressure fuel line) the only difference is the tune.
This data log is going to be a 3rd and 4th gear pull. Key takeaways are:
- Brief spike of fuel pump duty to 100% but it only lasted 1 second before falling back to below 90% with only a brief spike to 91% when in fourth gear. During that brief 100% spike you can see the DIFP actual drop as well. Again this is considered okay as long as it is for only a very very short period of time.
Then, below, the Flex Fuel parameter part of the graph, again only to show the exact amount of ethanol being used. For the most part, the whole data log is on a 20% blend with only a few spikes to 21%. Again, this view more clearly shows the “noise” or erratic nature (spikes and valleys) of the fuel pump duty throughout 4th gear.
Lastly, the boost graph is shown for complete transparency and shows the amount of boost throughout the whole data log. As you can see during third gear upon just going WOT (wide open throttle), the boost does spike all the way to 23.9 PSI but remains at or below 22 PSI for the whole rest of the pull.
This is a higher boost number compared to the 26% ethanol blend numbers because…
- This is the Phearable.net stage 3 OTS tune.
- Air temp is 30 degrees cooler than the 26% log.
And of course, I’m again sharing the MP4 of all the sensors for the Phearble.net stage 3 OTS tune with the OEM fuel pump, just for all the naysayers to have complete transparency into what’s going on.
To conclude this experiment, we will now examine the data logs for the Phearable.net Stage 3 OTS tune with AEM LPFP installed. Once again, we will be analyzing 3rd and 4th gear pulls. I also want to mention that these logs were both done on the same exact flat stretch of highway, so there is no difference in load or lack of load being put on the car by either going up an incline or down a decline.
We begin again by examining the Fuel Pump duty cycle graph from the AEM LPFP data log. Similar to the OEM data log, we observe an initial rapid increase to 100% duty as boost pressure rises. This is then followed by a swift decrease to a significantly safer level below 90% duty. Furthermore, the graph exhibits a reduction in “noise” or erratic behavior within the fuel pump duty cycle. While a definitive correlation with the increased fuel output of the AEM LPFP cannot be established at this stage, a visual comparison with the previous data logs for the 26% ethanol content run and the Phearable.net Stage 3 OTS tune with the OEM LPFP suggests a potential link.
We now turn our attention to the Flex Fuel data log graph presented below. Similar to the previous graphs, this one offers a clearer visualization of the fuel pump duty cycle, exhibiting a marked improvement in consistency (reduced noise and erratic behavior). Notably, despite my efforts, the ethanol content measured during the AEM LPFP data log did not fully align with the OEM LPFP data log. The ethanol concentration was recorded at 20% during the OEM LPFP log, whereas the AEM LPFP log indicates a reading of approximately 22% for the majority of the run.
This observation lends credence to the claim that replacing the stock LPFP with an aftermarket one can reduce stress on the fuel system. The data shows a decrease in the erratic behavior of the fuel pump duty cycle, even while accommodating a 2% higher ethanol content.
To ensure transparency and verify the consistency of the boost pressure readings, we will now revisit the Boost data log. As observed previously, the boost pressure exhibits a rapid increase upon spool-up, reaching a peak of 23.3 PSI before stabilizing within the 21 PSI range.
And finally, again, the MP4 of all the sensors from the 3rd-4th gear pull with the AEM LPFP for complete transparency.
Now I just wanted to zoom in and highlight again the erratic nature of the fuel pump duty line with the OEM LPFP in 4th gear (the up and down red line on the upper portion of the graph)
To show a direct comparison, we now present a zoomed-in view of the fuel pump duty cycle for the AEM LPFP data log. By scrolling vertically, you can readily compare the behavior of the fuel pump duty lines from both configurations. It is evident that the AEM LPFP exhibits a significantly higher degree of consistency compared to the OEM counterpart. Furthermore, it is important to reiterate that this improved consistency is achieved while accommodating a higher ethanol content of 22%!
To comprehensively address any potential inquiries or reservations, I have included the following MP4 file. This datalog captures a complete pull beginning in 1st gear from 12 mph topping out at 136 mph in 5th gear using the Phearable.net Stage 3 OTS tune with the AEM LPFP.
One last time… an MP4 of all the sensors for that full pull.
It’s clear that augmenting an engine’s power output correspondingly escalates the heat it generates, which indeed counteracts the enhanced cooling effects afforded by the use of increased ethanol.
I also understand that installing a fuel pump and having to cut and splice together two measly wires isn’t the hardest thing on earth. But, if you’re like me and you don’t like to cut/splice or do any modification that isn’t plug-and-play or 100% bolt-on, then the Wunderladen kit is definitely something you need to look into.
Another important note. The “noise” or erratic behavior I’m comparing is what the HPFP is doing when the ECU is demanding fuel. My results seem to suggest that adding an aftermarket LPFP that has a larger output than that of the OEM LPFP can more easily supply fuel to the HPFP, thus preventing the “noise” or erratic spikes. Remember, in all three data logs I had the Modified High-pressure fuel line installed too, this is what leads me to believe that by installing the AEM LPFP I have effectively improved my overall fuel system’s performance.
I just want to be clear that in no way was this a tuning how-to. I have no experience when it comes to tuning these cars, or any cars for that matter. I understand things like duty cycle, timing tables, knock, air-fuel ratio, etc., but I don’t know how to translate that into successfully tuning a car let alone the complicated Bosch ECUs that our cars come with. In this post, I’m simply sharing first-hand experiences that I have encountered and observed. The statements I made about ethanol levels are generalized blanket statements. If all you are doing with your car is frequenting Cars and Coffee events and occasionally doing some pulls on the freeway to impress your brother-in-law, then I’m sure you can get your car tuned to run E40 on a stock fuel system; heck, my buddy did, and he made great power with a reputable tuner, but again, it wasn’t sustainable. However, he did have a cool dyno chart to brag about and use as “proof” in Facebook arguments. Oh, and for the track fiends out there, pushing their machines to the limit under the unforgiving eye of the clock – don’t kid yourself. Running E40 on stock fuel systems is a pipe dream. So put away those illusions of grandeur and start facing reality.
Again, I want to reiterate my firsthand experience of running E35 in my car at Buttonwillow, on a BASEMAP tune, repeatedly running sub-2-minute laps. In the afternoon, as the weather got warmer and the car started to get hot, I began to run into issues caused directly by running an E35 blend in these harsher conditions. But then, after diluting it down to E27, I was able to continue driving lap after lap without any sort of hiccup. That alone should be enough to convince you that you should not run above E30 when flogging the crap out of your car. Unless you’re slow… which it is ok to be. Just don’t go around spreading misinformation about ethanol content and how you track your car. Make sure you preface all statements with; that you are a novice and are barely pushing the car hard at HPDE (High performance driving education) events.
I understand that many of the topics covered in this post are very controversial and subjective, and do not conform to the peanut galleries’ opinions. I’m okay with that because my ethos is longevity, not likes. My focus has been on creating a safe and reliable long-term setup for my car, no matter how hard I beat on it. Lusting after high horsepower numbers has never been my goal. I’ve intentionally stayed well within safe boost numbers, my fuel pump duty is well within safe limits, and my timing is more conservative than your grandma’s Sunday dress. Transparency is my middle name. Data logs? I’ve got snapshots, full MP4s, the whole nine yards. Every detail is out there because I have nothing to hide and nothing to prove.
The sections of this post that delve into topics such as ethanol levels, power figures, acceptable parameters for fuel pump functioning, alterations to the fuel system, and comprehensive tuning aspects are based on my own direct experiences and observations from those experiences. I’m only trying to share information and give the readers some sort of base to go off of. That being said, there are definitely reputable tuners out there that can tune your car to run safely on E30 with a stock fuel system. The problem is finding and trusting the right ones, as many claim to be experts. Being certain that you have selected the right one can feel like a gamble with lower odds than winning at the Vegas Strip.
And if you frequent the track, I would make sure to tell your tuner what you plan on doing with the car to ensure the tune they create is safe and reliable.
As you can see from my data logs, there really isn’t large amounts of definitive evidence to prove one way or another that adding an aftermarket low-pressure fuel pump is something you need to do. As stated earlier, the only real change between the OEM pump and the AEM pump was the lack of erraticness of the fuel pump duty throughout the 4th gear portion of the datalog. If you really closely analyze the logs too, you might even notice that with the AEM LPFP installed, the fuel pump duty does average below ~85% (if you calculate all the peaks and valleys and then find the average of those numbers) compared to the OEM LPFP log (which averages out somewhere around ~88%).
It is also important to understand that the fuel pump duty cycle being measured via Hondata is the high-pressure fuel pump duty and not the low-pressure fuel pump duty. My theory is (and the data somewhat backs it up) that by swapping to an aftermarket low-pressure fuel pump with a higher output, it is more capable of supplying fuel to the high-pressure fuel pump, which helps the high-pressure fuel pump run more consistently (less erratically). Keep in mind too that I do have that modified high-pressure fuel line which could also help my fuel pump duty be slightly better than someone without it who just installs a LPFP. Like maybe, the Modified high-pressure line works even better in conjunction with the Aftermarket LPFP?
- While it's ideal to be right at your targeted fuel pressure, you will likely lose a little bit of pressure near 90% fuel pump duty. Staying within 5 bars is perfect, being within 10-15 bars is acceptable, but any further drop necessitates changes to the tune. If the pressure manages to drop to about 160 bars from a commanded 200 bars, the engine will go into a protection mode that lowers the max torque request, richens the fuel, and starts putting out black smoke.
- Running a K20C1 engine with significant fuel pressure loss is a major risk factor for damage. To prevent this, avoid maxing out the HPFP.
Swapping for an aftermarket LPFP doesn’t conclusively show any reason to necessitate an installation of one. However, there was enough evidence in the data logs for me, that it does make some sort of improvements, and at the very least, it will give me peace of mind that I have alleviated some amount of stress from the overall fuel system even if only running small amounts of ethanol. Thus, keeping my car just a little bit more reliable when running it hard. So YES! I would recommended this to all my friends who own FK8’s. Simply because it’s cheap, and fairly easy to install.
Choosing the right tuner for your car can feel like navigating a secret society. While forums and Facebook offer a wealth of (mis)information, crucial details often remain elusive to the inexperienced. This lack of transparency can leave car enthusiasts like myself wishing for a guiding hand.
That’s why I’m sharing the hard-won insights I’ve gleaned from my tuning journey. This information is for those who crave the straight facts without the guesswork.
Forget wading through endless online threads or “word of mouth” suggestions from people who probably don’t even own a Type R on Facebook (but they are planning on getting one). In this painfully long post, I have shared with you the intel you won’t find with a simple web search: the key questions to ask tuners, the red flags to watch for, and the secrets to a successful tuning experience.
Empowered with this knowledge, you can approach tuner selection with confidence. No more second-guessing or regret from choosing an inexperienced one. You also should have a better understanding of what fuel system modifications you need to get to the power levels you’re after safely and reliably.
No doubt, there is some very valuable information that you won’t be able to easily come across just by searching the web. I just wish someone had shared these insights with me as transparently as I have just done so that making my decisions about tunes/tuners a much easier process without hesitation.
The Bosch ECU that comes equipped on the FK8/FL5 chassis is highly sophisticated and extremely complex, and it has so many safety nets in place to help ensure the car doesn’t damage itself. That is why this post was so incredibly comprehensive… there is so much information needed to even begin to comprehend the very basics of it. Even if you have been playing with Hondas for the better part of 30 years… none of that translates into these cars. For that exact reason, I maintain that finding a tuner who exclusively deals with these cars will be key in guaranteeing your car will run safely and reliably for years to come.
To sum it all up… Even though the evidence isn’t glaring, I wholeheartedly recommend installing an aftermarket LPFP! It might not make drastic improvements, but as seen in the data logs, it does help, guaranteeing peace of mind that is invaluable, particularly for those considering flex-fuel options. It’s a worthwhile investment that pays off.
As always, thank you so much for taking the time to read my ramblings. Trust me, buried somewhere underneath the rants, hard pills to swallow, and long-winded explanations is some really good information. This post required significantly more time and effort to draft than usual due to the complex nature of the topics discussed. As with all my posts, to ensure accuracy, I had to do much research to ensure that what I’m stating is factual and lord knows, the proverbial rabbit hole of tuning is DEEP. This post also had the most amount of “rough drafts” of any of my posts. This was mainly because I had to make sure I tiptoed around certain topics so as not to ignite a war which required numerous rewrites after proofreading.
If you found this post helpful in any way, I would love to hear from you. Heck, if you found this post useless, I would still love to hear from you because that means I could stand to learn a thing or to from you. Or, if you just simply want to say hi… Please do not hesitate to reach out via email; Billy@Functiontheory.com, Instagram; @Functiontheory, or simply comment on the post below, and I will get back to you.