Oil Cooler Removal?!

Ah, buckle up for a tale of automotive adventures and unexpected cooling conundrums! Picture this: While the world spins in a frenzy to install oil coolers on their FK8’s, I find myself defying the norm by removing mine. What madness, you ask? Well, let me regale you with the untold saga of how an innocent little oil cooler turned into a radiator-blocking mischief-maker.

Adding an oil cooler to your car promises improved performance and lower operating temperatures, RIGHT?

Oh, how wrong I was!

Let’s go back to when I first installed the oil cooler. At first, things seemed hunky-dory. The oil cooler dutifully fulfilled its role, chilling the engine oil and seducing me with the promise that all my overheating issues would be solved. But little did I know, a sneaky issue was creeping up on me, ready to pounce on my dreams of solving the FK8’s overheating issues.

At the time of installing the oil cooler, I didn’t have a way to accurately monitor oil temps. I was just banking on the fact that now because I had an oil cooler (especially of this size) installed, I would never have overheating issues again. However, as you’ll read below, my hopes were built on empty promises that the oil cooler couldn’t deliver.

In certain situations, there can be an issue where the positioning of the oil cooler and intercooler obstructs the flow of fresh air to the radiator. This can result in a reduction in the cooling efficiency of the radiator, as the air passing through has already been heated by the heat exchangers. It is crucial to ensure proper airflow to maintain the optimal temperature of the radiator and avoid any potential overheating issues.

As you can see below, the oil cooler I have installed has blocked just about every inch of fresh airflow to the radiator.

I mean, just look at it. There is absolutely no room. I’m sure you’ll notice too that I even cut out my 20/21 grille to help aid in increasing fresh airflow to the radiator.

But, If you look closely, even the braided cooler line that runs over the top of the cooler is blocking any last attempt of fresh air that the grille cutouts could provide. I have seen some install the same oil cooler I have and they were able to run the braided cooler line behind the cooler itself. I did try to do this but was unsuccessful because the radius was too tight on the 180-degree AN fitting coming off the oil cooler, and it interfered with the cooler itself. (The fitting 180* bend is too tight and hits the cooler itself because of how thick it is.)

You can read about my oil cooler/Intercooler install by clicking the link below.

(flashback to last year, April 2022) Okay, so here I am, very excited that my overheating issues will be a thing of the past. I’m so certain, that I even signed up for a Speed Ventures/HTAC event here at LVMS.

Let me set the mood for you. It’s just your average April Saturday in Las Vegas. Hot, but not blazing hot, with temps reaching the 80’s. But hey, I’m not sweating it (literally) because I’ve got an oil cooler and a sick aftermarket intercooler installed.

I was pumped for my first session of the day! The weather was windy, but the morning temps were in the high 60s, so it was all good. I started to attack and after just two laps, I glanced at my LogR screen. And guess what? I nearly freaked out! The ECTs were already hitting 220 degrees Fahrenheit, man! Can you believe it? With the temps only in the mid-60s! Wild!

Immediately, It was a facepalm moment for sure when I realized my worst nightmare had come true. I totally messed up by blocking all of the fresh cool air from getting to the radiator with that beefed-up intercooler. And to top it off, why on earth did I think it was a good idea to stick an oil cooler right in front of the radiator? What an idiot!

Ah, the infamous issue of blocking airflow to the radiator! They were hot topics on the forums, pun intended. The word on the street was that the HPD cars opted for the trusty OEM intercooler. Now, in the recesses of my mind, I couldn’t help but anticipate some lingering overheating woes, even with the oil cooler and intercooler in tow. And let’s not forget, I have a 20/21 FK8, which conveniently houses the LKAS sensor right where those side-mount oil coolers would typically reside. Which is why I opted for the oil cooler to go in the grille. I figured any oil cooler was better than no oil cooler… I couldn’t have been more wrong.

Throughout that day, despite only reaching temperatures in the mid-80s, my vehicle encountered a significant challenge with overheating. The engine coolant temperatures soared to unprecedented levels, surpassing even those observed during one of my previous track days at SMMR when the outside air temperature reached a scorching 95 degrees Fahrenheit, and my car didn’t even have half the cooling modifications I currently had. It was clear that having the oil cooler blocking the radiator was not the move.

Throughout the day, the factory ECT gauge (on the left side of the cluster) was reading a few marks above its normal mark, and it was clear that the car was pulling timing. This was similar behavior to what I had experienced on another one of my previous track days when the temperatures were in the high 90s, and I had a stock intercooler and no oil cooler. However, I’m happy to report that the 27won intercooler, despite blocking all cool air from the lower half of the radiator, was doing its job and helping keep those IATs low.

Despite all this, I still ran each session for the rest of the day and continued pushing the car hard, even though the ECTs were well into the 245+ range. This probably isn’t the best thing for the car, but honestly, when I’m on track I only see red, and I’m only concerned with going as fast as possible. This is why I pamper the car so much in every other aspect; Oil changes every one thousand miles, trans fluid changed after 4-5 track days, wash/wax it weekly, and continue to dump all my retirement into it.

I bet I know what you’re thinking… You’re thinking, all this overheating stuff is because I have the stock grille. And I wouldn’t have any issues if I had an aftermarket grille!

Hold on fam…

Yep! That’s right, I tried that too. With the aftermarket J’s grille you can clearly see just how much the oil cooler and braided line are covering the radiator (well technically the A/C condenser. But the condenser is mounted to the radiator, so for all intents and purposes lets just loosely call it all the radiator.)

So after realizing that the oil cooler and intercooler were not going to solve the issues, I decided to try more drastic measures. Click the link below to read about how I installed a titanium inlet pipe and switched to flex fuel in a desperate attempt to lower ECTs. For those that don’t know Ethanol or E85 helps reduce temps in the combustion chambers and thus can potentially lower overall ECTs.

After doing everything listed above, I headed to Buttonwillow (in late 2022) hopeful that my overheating woes would be a thing of the past. Just for reference let me list below all the cooling mods that I had on the car so you are clear on the lengths that I have gone to prevent overheating.

  • First Molding vented hood.
  • J’s grille.
  • Koyo radiator.
  • Acuity reverse hoses.
  • 27won intercooler and Boost tubes.
  • Greddy oil cooler.
  • Flex-fuel (e20-e25)
  • RV6 Ceramic coated high flow cat.
  • RV6 Ceramic-coated front pipe.
  • Gold heat-reflecting tape on the oil pan where the front pipe runs.


So, even after all those changes to the car, I was still having issues with it overheating on the track. It was definitely better than before, and I could get more laps in before it started acting up. The good thing was that with all the cooling modifications, the car would cool down pretty fast once I slowed down a bit. I just had to go about 6/10th of my usual speed, and the car would quickly get back to normal. Most of the time, it would happen in less than a full Buttonwillow lap.

Unfortunately, after much sleuthing, I was ready for that hard-to-swallow pill. I recognized the culprit: the conniving oil cooler! Yes, my dear friend, rather than sharing the airflow love with the radiator, it decided to play the ultimate blocker. While it successfully chilled the engine oil, it shamelessly hogged all the cool air, depriving the radiator of its much-needed cooling breeze.

Can you believe it? An oil cooler with a mischievous streak! It turns out that my vehicle’s cooling system was in dire need of some radiator TLC. It had come down to prioritizing cool oil or cool ECTs. And yes, while they are both equally important, after careful consideration (and a few muttered profanities), I made the tough decision to evict the oil cooler from its ill-gotten throne.

Let me elaborate further on the topic of oil coolers.

When it comes to oil coolers, it is important to consider the specific type of cooler being used. The information I provided earlier is particularly relevant for oil coolers that are designed to be mounted in the grille. It is worth noting that this particular type of oil cooler may present certain challenges and limitations.

While a side-mounted oil cooler may not be affected by the issue mentioned earlier, it is essential to understand the potential drawbacks associated with using a large oil cooler like the Greddy one. Despite its ability to effectively cool the oil, its size can often impede the free flow of fresh air. Also, because of the oil cooler, the temperature of the air now hitting the radiator is 240+ degrees F. The radiator is designed to transfer heat from the hot coolant that flows through it to the air that passes through. If the air passing through the radiator is hotter than the coolant, then the hot air will not be wicked away by the airflow, leaving you with an inefficient cooling system.

The obstruction caused by a large oil cooler blocking a significant portion of fresh air flow into the vehicle’s radiator and other cooling components can lead to increased operating temperatures. This, in turn, may impact the overall performance and efficiency of the engine and or cooling system.

It is crucial to strike a balance between the cooling benefits provided by an oil cooler and the potential drawbacks associated with reduced airflow. Consider consulting with a qualified automotive person or conducting further research to determine the most suitable oil cooler for your specific vehicle and cooling needs. NOT JUST CONSULTING FACEBOOK!

I hope this expanded explanation provides you with a more comprehensive understanding of oil coolers and their potential impact on airflow. If you have any further questions or require assistance with any other topic, feel free to ask!

Recently (January 2023) I hooked up a DEFI oil temp gauge in my car and put the sensor in the aftermarket oil pan. I’ve actually had the oil pan installed for a while now, but just never got around to installing the gauge. The only bummer is that I didn’t have the gauge installed before putting it in the oil cooler. So, I don’t have a reference for the oil temp “on track” before the cooler was installed. On the flip side, I also don’t have a reference for oil temp “on track” with the cooler installed because I haven’t done a track day with both the oil cooler and temp gauge installed at the same time. It’s a bit of a bummer, but that’s how it turned out!

See below the aforementioned oil pan with said bung.

Here’s the deal: I installed the oil cooler back in March 2022. That year, I participated in a few events; my last track day in that year was in November 2022. Then, in January 2023, I decided it was finally time to get some real data and installed the oil temp sensor.

But then, in February, Angie and I welcomed a baby into the world! As you can imagine, track/car stuff had to take a back seat for a while. However, during Angie’s maternity leave, I managed to sneak in one last event in May 2023. It was going to be one final hurrah before taking a hiatus from tracking the car, so I went all out preparing my car so I could wring out every last drop of performance.

You see, the oil cooler was a real pain in the neck when it came to the car overheating. When I was getting the car ready for one last hurrah on the track in May, I had to make a tough call. I decided to prioritize the engine coolant temperature (ECT) instead of worrying about the oil temperature and just got rid of the oil cooler altogether. Let me tell you, I had been agonizing over this decision for months, going back and forth in my head. Should I keep the oil at a steady, optimal temperature or focus on the coolant? Ideally, I wanted both to be at the perfect temperature, but hey, life doesn’t always give you what you want.

By bidding farewell to my oil-cooling companion, I hoped to restore balance to the engine’s temperature harmony. Yes, it meant sacrificing the supposed benefits of the oil cooler, but hey, who needs an oil cooler when you’ve got a radiator in desperate need of a cool draft?

Below the pictures depict the steps taken to remove the oil cooler and switching to VP stay frosty coolant.

Jumping right in… I had already taken out 10 million plastic clips and screws that hold the bumper on and removed it. I also removed the intercooler as well to fish out the oil cooler lines.

It is also worth noting that I had to “trim” the J’s grille a little when I originally installed it to get it to clear the massive oil cooler. You can see below how I had to not only remove the metal mesh but also cut a large portion of it out on the lower part.

Originally, I was simply going to remove the bumper and try to reroute the oil cooler line in hopes of increasing airflow. BUT…

Check out the 180* AN fitting that totally messed up my plans to route the oil cooler line behind it. I was hoping to improve the cooling slightly by simply rerouting the line, but guess what? The core of the oil cooler was too thick for the radius of the 180* bend to fit around the side. I even tried bending the AN line, but I just didn’t have enough muscle power to make it happen and was more worried about breaking something. So, I decided to ditch the whole thing and now that I have an oil temperature sensor in place I can at least get a baseline oil temperature for when I’m on the track.

Also, keep in mind that the oil cooler IS centered, it just looks off-centered from this specific camera angle.

Below, you can see the significant interference caused by the oil cooler braided line with the airflow, which compelled me to pursue a re-routing solution. Considerations were given to acquiring fresh lines and fittings that would allow for a more efficient re-routing. Regrettably, the exorbitant cost associated with obtaining several feet of braided lines and AN fittings promptly halted this course of action. The expenses for new lines and fittings alone would amount to several hundred dollars, while for just a slightly higher investment, a side-mounted oil cooler could be acquired.

Below you can see how tightly those lines are crammed through there. Plus the 27won intercooler has a unique hot side that helps aid in increasing airflow and that makes things even tighter through there.

Below you can see the unique hot side of the 27won intercooler.

Check out how much more surface area the radiator has now for that cold air to flow through. Pretty cool, huh? get it… 😉

Below you can see the LKAS sensor that deters me from putting a side-mounted oil cooler. Yes, it is possible to install one, but the sensor will be blocking most of the airflow to the oil cooler. I’m still toying with the idea of simply unplugging the sensor and removing it. However, I’m fearful that if it somehow prevents my car from fully functioning I will need to get it calibrated at the dealer when I reinstall it. There is also the European brand HEL, which makes a side-mounted oil cooler that works in conjunction with the LKAS sensor. I’m also interested in pursuing this approach too.

Picture this: imposing and immovable, a colossal intercooler swoops in like a boss and totally barricades the poor radiator’s lower half. And hey, that’s not all! This aftermarket intercooler, if you haven’t heard, is thicker than OEM. So now, on top of being a blockade, it’s also a speed bump, slowing down the airflow like a turtle chasing its dreams. Poor radiator, it never saw it coming! This is why some may argue that the OEM intercooler is preferred when on track.

However, I noticed a significant variation in the Intake Air Temperatures (IATs) after installing an aftermarket intercooler. This change suggests that the introduction of cooler air into the engine has a substantial impact on performance, making it worthwhile to consider partially obstructing the radiator.

It’s when you begin blocking off the upper half of the radiator that things start to go south.

Below is an older picture, but you can see how the OEM intercooler still leaves some room for air to flow to the radiator.

And then how much the 27won intercooler blocks. Keep in mind that most aftermarket intercoolers are big like this and block all the airflow. But the payoff is cooler IATs. This picture really does a great job showing you just how much of the airflow to the radiator is obstructed by an aftermarket intercooler.

The intercooler plays a vital role in mitigating the high temperature of the charge air emitted by the turbocharger. Through the implementation of fins and plates, the intercooler effectively dissipates thermal energy. The forced airflow propels the heated air through the intercooler, while the intricate fin structure facilitates the transfer of heat to the ambient environment. This crucial process ensures that the incoming air remains sufficiently cool, enabling the engine to operate with heightened efficiency. Furthermore, the utilization of an intercooler serves to enhance the longevity of the engine or system by preventing overheating. It is important to note that the dissipated heat, which is directed toward the radiator, eradicates any potential ECT cooling efficiency gains. Plus the thicker the intercooler, the less velocity the air has as it travels through the intercooler, and then you end up with less overall airflow to the radiator.

Another great comparison highlighting the differences in the OEM and 27Won hot sides. This is why the 27Won intercooler made for a tight squeeze getting those oil cooler lines through there.

And one last side-by-side comparison.

Let’s dive into what I believe to be the pivotal moment in the FK8 owner’s journey to address overheating concerns. This exciting discovery came about during my search on the Dream Automotive website for the HEL oil cooler. While on their site I came across many coolant additives that promise to aid in cooling efficiency, but one stuck out like a gleaming neon sign. The product was, VP Stay Frosty coolant, and it was not just an additive but a complete coolant replacement.

The so-called coolant additives that supposedly enhance cooling efficiency have been in existence for quite some time now. However, I must admit that I am rather skeptical about the claims made by these “additive” companies and their alleged effectiveness. While the scientific principles behind them may seem plausible, the idea that simply adding a small amount of a substance can miraculously improve your cooling system feels more like wishful thinking than a legitimate solution.

The stand-out difference in the VP stay frosty is that it is not just an additive. It completely replaces all of your coolant and for that reason, it is much more plausible that there is a measurable impact on cooling performance.

There are two versions of the VP Stay Frosty coolant.

  • One is the “race ready” version (which I have) (blue color)
  • The other is the “Hi-performance” version. (purple color)

VP claims their Hi-performance coolant (Purple color) can cool things down by a whopping 14 degrees Fahrenheit! And if that’s not enough, their Race-ready version (blue color) can reduce the coolant temperatures by a staggering 37 degrees Fahrenheit. I’m not here to argue, just passing on the info. If you want more details, you can visit their website.

After researching a lot about the Stay Frosty product, I was totally convinced by those impressive numbers they threw at me, and it got me itching to take a leap of faith. However, there are a couple of downsides to the “race-ready” version I went for.

First off, no protection when it gets freezing cold. So, if the temperatures drop below zero, you’re totally screwed. Lucky for me, I’m living in Las Vegas where the winter chill rarely gets below freezing. Besides, I keep my car snug in the garage all the time. Even if it’s freezing outside, my garage isn’t that cold, so I can still fire up and warm my car without any issues. Once it’s up and running and warmed up a bit, it’s never cold enough in Las Vegas for it to freeze while driving. The only little worry I have is when I head to Buttonwillow in the winter and stay overnight in a hotel. There’s a chance it might freeze then, but if that’s the case, I’ll just change my plans and set off from home here in Vegas at 2 a.m. That way, I’ll roll into Buttonwillow just as those gates swing open at 7 a.m.

There’s another downside, my friend. VP suggests you gotta change the coolant every two years to keep it running at peak efficiency. And let me tell ya, that coolant ain’t cheap! It can really drain your wallet, especially when you usually don’t have to flush your coolant until you hit 100k miles or so.

If you’re worried about your engine freezing, you can go for the “Hi-performance” version and still keep the antifreeze part of your coolant. But let’s be real, a 37-degree temperature drop sounds way more impressive than just 14 degrees. That’s just my two cents.

On to flushing the coolant.

Here’s the deal: in theory, the factory service manual says there’s this magical coolant drain plug at the front of the block. But let me tell you, finding that thing is like searching for the lost city of Atlantis. It’s hiding behind the downpipe and O2 sensor, playing hide-and-seek like a mischievous gremlin. I mean, who designed this genius setup? Definitely not someone with an ounce of laziness, that’s for sure. Even if you can locate it (which I did) there is absolutely no way you’re getting to it without having to basically remove every engine accessory. So, in the spirit of embracing our inner couch potato, I took the more “creative” route to tackle this situation. Can’t say it’s the most professional approach, but hey, sometimes you gotta do what you gotta do, right?

So here’s what I did, no fancy jargon. First, I jacked up the car and then made sure the climate control was set to full hot on the knob. Then, I popped off the cap from the coolant tank and opened the radiator drain. While that was happening, I disconnected one of the hoses leading to the heater core and blasted water through the entire system using a good ol’ garden hose. Easy peasy, right?

I let the OEM blue stuff run clear, ya know, just to make sure I got all the old OEM coolant out. Then I turned off the hose and let the rest of the water drain out. Once it was completely drained, I screwed the radiator plug back in and reconnected the heater core line. Now, it was time to start filling up the cooling system with the VP Stay Frosty coolant.

Here’s how I do it, no fancy vacuum tools involved. I just grab a trusty coolant funnel and let gravity do its thing. Make sure I jack up the front of the car as high as possible. Then, I pour coolant into the funnel attached to the expansion tank. Having the front of the car raised up high, helps the air escape more easily while the coolant goes in. Once the funnel is filled up and the level stops going down, it’s time to fire up the car and crank the heater to the max. Make sure that the heat is blasting!

When you start your car, let it warm up to normal temperature, and make sure the fans come on and off at least three times. When the fan cycles, it generally means the thermostat is opening. Each time the thermostat opens it helps get rid of any air bubbles trapped in the system. Also, try giving the car some revs, this speeds up the rotation of the water pump impeller. This helps the coolant flow and break free any stubborn air bubbles as well.

As the car warms up and the thermostat opens for the first time, there will be many air bubbles coming out and you will have to add more coolant to the funnel. Again, make sure you let the fan cycle on and off at least three times to ensure that all air has been evacuated from the cooling system.

I’m a little OCD and I went the extra mile. I wanted to make sure that not a drop of that old OEM coolant was left to dilute the potency of VP Stay Frosty. So I did it all over again! I drained out the Stay Frosty that I had just put in. I used the same method as the way I had originally drained out the OEM coolant, repeated the whole flushing process once more with the hose, and then poured in another 3 jugs of fresh, brand-new Stay Frosty. I bled everything again, once more time. Can’t take any chances, right? Gotta keep things frosty!

While it may have come at a higher expense, I wanted to ensure that I was providing the VP Stay Frosty with the greatest opportunity to assist in resolving my overheating concerns.

After bleeding the cooling system again for a second time. I buttoned everything back up on the car, put it back on the ground, and took it out for a hard drive. This would ensure that if there were any pesky air bubbles still trapped, they would get worked out.

After taking the car out for a 30-minute loop around my favorite “test track”, I came home, let the car cool for a few hours, then opened the coolant tank and topped it off with stay frosty. You should notice that after driving the car hard for about 30-45 minutes, and then allowing it to fully cool, more air bubbles will have worked their way out and the car will have drank down some coolant.

Below, you can now see how much more surface area there is for fresh air to hit without the oil cooler installed.

Alright, now it’s time to read about the data from my most recent track day which I did in May 2023 after removing the oil cooler. And if removing the oil cooler and adding VP stay frosty was a good idea. If you wanna dive deep into the nitty-gritty of my last day on the track, just hit that link below. Otherwise, stick around for the deets on the temps I recorded that day.

Results from May 2023 track day with oil cooler removed and temp sensor installed;

During the first half of the day (before noon) air temps were peaking at 83 degrees F. as indicated on the dash. Oil temps would be nearing 265 degrees F, as indicated by the DEFI oil temp gauge (with the sensor in the oil pan.) However, ECTs were still okay at 210-220 F. as indicated by the LogR app, and the OEM temp gauge was still at its “normal operating temp” range on the dash. This alone was a big win for me! Because during prior track days with the oil cooler installed, I couldn’t make it two laps before reaching radical ECT’s well above 220 F.

I can only conclude that the VP stay frosty coolant was doing its job helping to reduce the overall temps. Just to confirm ECT was decent, I would open the Hondata app and find that ECTs were at 217 degrees. Don’t get me wrong… this is still hot, but it’s not the 230–240-degree ECT’s that I was used to seeing. Plus, it was reasonably hot in the high 80s without a cloud in the sky.

After lunchtime, the track went hot again at 1:15 p.m. By this time temps were in the mid to high 90s (with air temp indicated on the dash at 96 degrees). I did one more session, but the ECT temp gauge started to climb one or two ticks above the “normal temp range”, and it was not worth pushing the car to a potential breaking point or prematurely wearing it out just for the sake of being on track. When it’s that hot out, even an N/A car will start to struggle. Plus, I had already improved my PB that morning with a time of 1:58.79. Keep in mind this event was a Buttonwillow and was in May, so yeah… It’s hot.

IMO, once the air temperature gets above 90 degrees, there isn’t much that can be done to prevent the inevitable overheating that plagues so many of us FK8 owners. When it’s that hot out, the only thing cooling modifications can do is help the car recover more quickly. The turbo just produces too much heat, and because the turbo is cooled by the oil and coolant, this means that the oil and coolant are constantly being subjected to incredible amounts of heat. The more laps you do, the more the cooling system struggles to keep up with trying to cool things down, and it just becomes a domino effect.

Now for those that are interested in more specific data… I want to go all the way back to the beginning of this car’s life on track. I will break it down below by phases of my car modifications and the temps:

Phase 1;

My first track day with the car was in September of 2021. During that phase of my car, I had these installed cooling modifications.

  • First molding hood.
  • Acuity hoses.
  • Koyo Radiator.
  • PTP inlet pipe blanket.
  • Heat-wrapped OEM front pipe.
  • Cut OEM 20/21 grille.

During that day the temp was 95* Fahrenheit. The car never went into limp mode from heat (or fuel starvation) but the temp gauge on the dash did indicate a little more than halfway and my LogR app was showing ECTs at 240* Fahrenheit. I would, of course, ease up on the car when it would get that hot and try to do a cool-down lap but the car would take some time (about a full lap of the 3.4-mile track) to cool to “normal” operating temps.

Phase 2 was in early-mid 2022 and would include all the modifications listed above, and then:

  • 27Won intercooler with boost tubes.
  • Greddy oil cooler.
  • RV6 catted downpipe.

As mentioned earlier, I didn’t have the oil temp sensor installed when I had the car on track and this meant I had no real data on the improvements the oil cooler made (if any). However, read below my notes from one of the track days I did during this phase of the car.

Optimistically, I set out for my first session of the day. The weather was very windy, and the air temps were in the high 60s for that first session. Two laps in and I glanced over at my LogR screen to check the ECTs. I had to do a double-take!!! The ECTs were already in the 220-degree range after only 2 laps with air temps only in the mid-60s. These were numbers I would usually be experiencing on an 80-degree day after 3-4 hard laps without an oil cooler.

It was at that point I realized my worst fear was a reality. I had blocked too much airflow to the radiator by adding the larger/thicker intercooler. And obviously, putting an oil cooler directly in front of the radiator was not the smartest idea.

For the rest of my day, even though temperatures peeked in the high 70s my car still struggled and struggled badly with overheating. My car experienced some of the hottest ECT’s that I have ever seen before. Even higher than when I was at SMMR when the air temps were 95 degrees and had fewer cooling modifications.

I still ran each session for the rest of the day and continued pushing the car hard, even though the ECTs were well into the 245+ range (as indicated by LogR app). This probably isn’t the best thing for the car, but honestly, when I’m on track I only see red, and I’m only concerned with going as fast as possible. This is why I pamper the car so much in every other aspect; Oil changes every one thousand miles, trans fluid changed after 4 to 5 track days, Garage kept, only put a few thousand miles on it a year (mostly driving to Buttonwillow and back), and continue to dump all my retirement into it.

The results above were from the track day I did right after installing the oil cooler and intercooler. It was clear that putting that large heatsink full of 240-250-degree oil directly in front of the radiator was plaguing me. I am happy to report though, that my IATs dropped drastically going from 140 degrees F with the OEM intercooler, to barely 105 degrees F with the aftermarket intercooler.

I am also excited to report that I managed to snag a 3rd place finish in street mod class that day! Despite the overheating.

The third phase, mid-late 2022, includes all modifications listed above and then these:

  • Flex-fuel (e20-25 blend).
  • Hondata base map tune.
  • PRL TI inlet pipe.
  • J’s grille.

I honestly figured these would have been the modifications that were going to end all overheating. Unfortunately, because I still had that oil cooler installed directly in front of my radiator, not even flex fuel and a J’s grille could fix the overheating issues.

Again, I still didn’t have an oil temp gauge installed and was not able to accurately measure oil temps. During this third phase, the car acted much like it had done when I did my first track day with it. ECT temps would be in the 230’s-240 range however the car would be able to bounce back from overheating much quicker. Now it would only take me about a third of a Buttonwillow lap taking it easy to get the ECT’s back down to the 215 range.

The overall issue in all three of these phases is that my ECTs are still getting way too high. When they get too high, the OEM ECU does correct and reduces the engine’s power output. Plus, running 220-230+ ECTs is not good and is going to eventually lead to head gasket issues, there is no way around that. I just need to figure out a better way to cool the engine coolant.

At the end of phase three, I installed the oil temperature gauge. I was able to finally start getting actual readings of oil temps and not just some LogR number that was based on calculations from other sensor inputs of the car. That’s right, if you didn’t know, the LogR app doesn’t display a real-time oil temp number. There is no factory oil temp sensor (for US models). The log R app takes readings from the ECT, IAT, and I believe oil pressure. There is some sort of calculation of those three numbers that takes place and then displays a number of where it thinks the oil temp is based on pre-determined numbers on some sort of scale made by Honda engineers.

Unfortunately, I never took the car on track with both the oil cooler and oil temperature sensor installed at the same time. However, I do have some baseline numbers from driving around town and spirited drives through some twisties just outside of town.

During normal operation, the oil temp would never get above 190 degrees Fahrenheit. This is because the Greddy oil cooler came with a trust sandwich plate that had a 180-degree thermostat. It didn’t matter if it was day or night, freeway driving, or in traffic. The oil temp never went above 190 degrees, EVER. This was great! Even when out on spirited drives in the twisties outside of town I couldn’t get the oil temp to exceed 210 degrees.

Now, with real-time accurate data coming from a temperature sensor in the oil pan, it is clear that the oil cooler is performing its job exceptionally well. Unfortunately, it is blocking airflow to the top half of the radiator, and the limited air that reaches the radiator has already been heated by the hot air expelled from the oil cooler. Despite these efforts, it still fails to resolve the issues of engine coolant temperature (ECT) overheating.

As you read earlier… After long contemplation, I decided that it was probably not a good idea to have that big ol’ heatsink blocking the radiator. Plus, I figured this could be a good opportunity to see how the oil temperature behaves without the oil cooler now that I have real data to go off of.

Now on to the fourth phase of the car: sans oil cooler!

  • First molding hood.
  • J’s grille.
  • 27Won intercooler/boost tubes.
  • Acuity hoses.
  • Koyo Radiator.
  • VP stay frosty coolant.
  • RV6 ceramic coated catted downpipe and front pipe.
  • PRL TI inlet pipe.
  • Flex-fuel (e20-25 blend basemap tune)
  • Gold tape on the oil pan where the front pipe runs.

During phase 4 of the car, the oil temps on the track were off the charts, peaking at a scorching 270 degrees Fahrenheit! (as indicated by the DEFI gauge) Meanwhile, the coolant temps were keeping their cool, never going above 220 degrees F, except in the hot afternoon when it was a toasty 96 degrees out. But hey, that whopping 270-degree oil temp is definitely not doing any favors to the engine, probably causing some serious wear and tear. Yikes, I need to get the oil-cooled somehow!

Honestly, I think the VP Stay Frosty was a game-changer. It did a pretty good job of keeping things cool when the day started. But as temps rose to a staggering 96 degrees F, the stay frosty couldn’t do much anymore. If the temps stayed in the 80s, the VP coolant would have rocked at keeping the ECTs below 220 degrees Fahrenheit. Sure, there are haters who think the stay frosty is a waste and just snake oil. But time and time again, it’s been proven that there is no one miracle cure-all for the FK8 and you need multiple modifications to tame the overheating issue.

With that said, stay frosty alone won’t cure it all, but when used in conjunction with other supporting mods it can make for a potent weapon in the fight against overheating. Some might say it’s pricey. Well, yeah, it is. But honestly, it’s one of the cheapest ways to improve your system’s cooling efficiency, except for maybe Acuity hoses, but even those only claim to lower your ECT by 2-5 degrees F.

When it comes to enhancing your cooling system, there are a few modifications that have proven to make a significant impact. First and foremost, I highly recommend installing a vented hood. This upgrade allows for better airflow and improved heat dissipation, resulting in a cooler engine temperature. Additionally, consider adding a J’s grille or a similar aftermarket grille. These not only provide a sleek aesthetic but also enhance the airflow to the radiator, further aiding in cooling. Lastly, don’t forget about the VP Stay Frosty coolant. This exceptional product helps maintain optimal engine temperature, ensuring your vehicle stays cool and performs at its best.

I might also say to get a radiator, but only if you don’t have a 20/21 radiator and only if you have done the other three modifications I recommended first.

All the other cooling modifications only make small nominal improvements that aren’t even measurable.

Oh, by the way, I’ve been really concerned about my oil temperatures hitting 270 degrees on the track. This is definitely NOT ok. I’m actually on the lookout for a solution to install a side-mounted oil cooler. Don’t get me wrong, I’d never recommend going without an oil cooler, especially for the FK8 that sees track time. I just think that having it mounted in front of the radiator might not be the best idea.

So, there you have it, folks — the epic tale of how an oil cooler turned out to be the radiator’s arch-nemesis. Remember, every car has its quirks, and sometimes, the best solution is to bid farewell to malfunctioning mods and restore order in the realm of cooling.

And if you’re considering embarking on your own automotive escapades, always remember: beware of cunning oil coolers disguised as cooling heroes. They may charm you with promises of power, but they just might end up blocking your radiator and leaving you in a sticky, overheated mess. Safe travels, my fellow automotive adventurers! May you never encounter the mischievous antics of a rogue oil cooler on your journey through the winding roads of motoring mayhem.

Hopefully, my journey has helped highlight the fact that you shouldn’t just throw every single aftermarket part on and assume you’ll be better off. There is a delicate balance between combining the correct parts and understanding what your overall goals for the car are. Are you a Drag racer, Roll racer, Track racer, or just a weekend warrior? Are you keeping stock power, or putting a moon tune on it? Either way, I think it can safely be said that like most things there is not a “one shoe fits all” type of solution.

If you made it this far, thank you so much for reading my super longwinded, painfully drawn-out write-up about overheating, oil coolers, and VP stay frosty. Please remember, take all this with a grain of salt as these are all very subjective opinions based on my first-hand experiences and there are many variables that contribute to whether your car is going to overheat or not.

I strive to offer valuable insights and raise awareness about various topics that may not commonly come to mind. It is important to note that the data obtained over the past three years, during which I tracked the car, may have certain limitations in terms of consistency. Factors such as varying temperatures and modifications could potentially affect the analyses and lead to less precise conclusions. I’m sure that the results would also have varied some if I had prioritized the modifications differently.

However, no matter what the FK8 will always be plagued with overheating woes.

Oh, believe me, I’ve seen some folks out there who swear their FK8’s are as cool as ice on a hot summer day. They’ll even introduce you to their buddy who apparently has a supersonic FK8 that never overheats. Well, well, aren’t they lucky! But for the rest of us living in the real world, where our cars have a tendency to transform into mobile saunas, overheating is a familiar foe. So, to everyone else out there who can relate, take a moment to chuckle and take my advice to heart. Cheers to keeping our engines cool and our drives drama-free!

This December 2023, I will be doing an event at Buttonwillow, and I’m confident that the car in its current (Phase 4) stage will have no overheating issues. Mainly because the air temps at Buttonwillow in the winter will be in the 40s-60s F. And I truly believe that with all my current cooling modifications the car will be able to stay cool even without the oil cooler. I’m also optimistic that with the air temps being that low, oil temps will stay below 250 degrees. I’m well aware that 250 degrees F is still too hot for oil, but I will be waiting until after that event to try and install a side-mounted oil cooler. I just want to gather data on oil temps in contrasting climates before adding an oil cooler again.

One last thing just for reference. Here is the temperature of my oil after driving around on a Las Vegas afternoon. Angie and I had taken the FK8 out to get some supplies so we could change the oil in our daily drivers and get some groceries. The ambient temps were around 103 F. as indicated on the dash, the A/C was on full blast, and I was driving like a respectable citizen not going over 45mph and shifting below 3k. As you can see the oil temp was at 210 degrees Fahrenheit!


  1. That was a good read, I get where you are coming from, 20 years age I built a 67 Plymouth with a 440 crate motor and wasted a lot of money, I never told my wife of all the different things that I tried that did not work. I am going to Buttonwillow this Friday, hope everything goes well, hope to see you in December, Bruce

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