[F87source]

Originally Posted by -Eidos

This is really good info. Next track day I'm gonna log temps for an entire open-pass HPDE session from grid to cool down and see how and if that differs from what you guys typically see.

What kind of temps are over heating cars encountering?

Yeah it's critical to log temps on track, probably the most important thing to keep an eye out for.

Coolant is always the issue, oil doesn't seem to be a huge problem. It's hot but not the cause of limp mode if you have a large oil cooler (another reason why I don't think getting a different thermostat is required, just get a good oil cooler).

117C is when timing gets pulled for coolant, 132C for oil. Coolant is always the issue, because the radiator is just so fricken small.

[shaneguags]

Originally Posted by F87source

Then mosselmann upgrade is just a low temperature thermostat, the bms valve is a complete delete. So you will not see any temperature improvements going from the bms sport valve to the mosselman thermostat, instead you'll see an increase in terms of oil temps. However warm up will be vastly improved.

I think if you push your car hard enough it'll over heat, there's no way around that. Even tyspeed with his ac delete race spec radiator upgrade couldn't keep his m2 cooled. He needed to do dual s55 aux rads + aux pump + radiator sprayers to keep temps under control. I really don't think there's much you can do for the n55 once you surpass 370 whp, there's just no way you can beat the radiator surface area limitations.


Also race gas is going to run alot hotter than e85 so you won't get the cooling effect of alcohol.

Yeah I know e85 has excellent evaporative cooling. But I am 110% certain that if you push the car hard it'll over heat. There's no way around that, no tune, no turbo kit, nothing is going to get around the fact that the radiator is massively undersized in this car and the fact that bmw cut corners making it - in favor of better packaging. There have been alot of people out there trying to solve this problem to no avail. I don't want to be negative but that's the reality of this situation.

ZM2 and I have been brain storming for years on how to completely solve this to no success, and he's tried many variations of what we came up with.

never knew that, thanks for that info !

[F87source]

I also wanted to add that what I keep seeing is people complaining about 103C oil temps on the street, that's actually not bad at all. About 90C - 105C is perfectly fine, remember the additives in engine oil needs temperature to work. Cold oil isn't exactly optimal but neither is super fricken hot oil. IMO the temps the stock car sees on the street even with hard driving is absolutely perfect, it is hot enough to burn off contamination, activate the additives in the oil, and get oil to its proper operating temps that provides maximum protection and low enough viscosity to reach all the areas in the engine with ease, yet cool enough to wick heat away from things that require oil for cooling (turbo bearings, rod bearings, pistons etc). So I really don't see the need for a low temp thermostat, but that is just me.


Now time to rant about bmw:

1) The m235i has an aux water pump, I really wonder what the heck bmw engineers were thinking about when they designed the m2 and were like "yeah we don't need this thing on our highest output n55".

2) The m235i has massive bumper openings for radiators but for the m2 they fricken cut the size down so much that the opening for the oil cooler was miniscule. I don't understand this at all, and then they realize this was an issue and rectify it on the m2C with larger openings. Again I don't know what bmw engineers are thinking.

3) This is related to 2, but the m235i has such a large intercooler opening in the front bumper that it can sport brake ducts. Yet on the m2 - again the most track capable 2 series, bmw engineers were like "nah this isn't needed", and then the m2 suffers from brake fade and caliper color shifting on track.


I really don't know what they were thinking most of the time when it comes to cooling. But thankfully they nailed it mechanically with the diff, subframe, suspension, and oiling from the s55. I am not sure why they didn't just transfer the s55 cooling over too since we know it fits.

[-Eidos]

Originally Posted by wilson kop

Understanding there are limits that can’t be avoided, I am curious what a vented hood, ceramic coating the downpipe and turbofold, and a turbo blanket could do for an intermediate driver on track.

FWIW, I have Inconel shielding on my downpipe, manifold, and turbo and underhood temps have improved tremondously. This was done more as a precautionary measure, but only good can come of it unless the metal of the thing you're wrapping exceeds it's thermal capacity (Which is why cast iron manifolds need to be coated or shielded). F87source may be able to scientifically explain it better 😁

[F87source]

Originally Posted by -Eidos

FWIW, I have Inconel shielding on my downpipe, manifold, and turbo and underhood temps have improved tremondously. This was done more as a precautionary measure, but only good can come of it unless the metal of the thing you're wrapping exceeds it's thermal capacity (Which is why cast iron manifolds need to be coated or shielded). F87source may be able to scientifically explain it better ��

Very nice! Do you have images of the wrap, I am really interested in that. It was always on my list of things to do - which is combat heat soak. This is my inspiration:

I really love OCturbojoe's workmanship.

[ZM2]

Loving this thread and convo, Gents!

[F87source]

I'm actually extremely interested in ducting right now because I think it will make a major impact. This is because the m2's factory ducting - well more accurately shrouding, is horrific. There are gaps everywhere, particularly when you switch to an aftermarket intercooler there is a massive gap on the sides on the intercooler that vent directly to the road. This must absolutely decrease pressure infront of the intercooler by quite a bit, and in turn affect air flow through the radiators. With better ducting cooling absolutely can be improved due to more flow going through the radiator. We can also play with expansion volumes, and thus cause air velocity to slow down by in turn increase air pressure. This will help with flow through the radiators as well.


Here is a video im currently looking at:

If I get some time this summer I will be working on the aux pump and learning to work with fiber glass so I can make cool ducts like this.

[-Eidos]

Originally Posted by F87source

Very nice! Do you have images of the wrap, I am really interested in that. It was always on my list of things to do - which is combat heat soak. This is my inspiration: https://www.youtube.com/watch?v=uSk13G-wPD8&list=PL-foDMQ9jBYOGRRRKZUppevXrLRp8SC_2&index=33

I really love OCturbojoe's workmanship.

I'll have to resurface the downpipe picture later, but looks similar to the turbo and manifold. I also had a little blanket made for the electronic wastegate actuator as well.

[F87source]

Originally Posted by -Eidos

I'll have to resurface the downpipe picture later, but looks similar to the turbo and manifold. I also had a little blanket made for the electronic wastegate actuator as well.

Very nice!

[shaneguags]

Originally Posted by -Eidos

I'll have to resurface the downpipe picture later, but looks similar to the turbo and manifold. I also had a little blanket made for the electronic wastegate actuator as well.

I was originally going to do that until I found out that the Funk Motorsport N55 manifold blanket works on the SpeedTech aftermarket manifold. just seemed easier for me since I couldn't find anyone to make custom heat shielding locally

[-Eidos]

Originally Posted by ZM2

Loving this thread and convo, Gents!

I'm getting some good data right now. ZM2 how long are your sessions, and how many hot laps do you do before doing a cooldown lap (if any?). And at what point in your session are you hitting the coolant/oil temp limits?

[ZM2]

Originally Posted by -Eidos

I'm getting some good data right now. ZM2 how long are your sessions, and how many hot laps do you do before doing a cooldown lap (if any?). And at what point in your session are you hitting the coolant/oil temp limits?

Hey! It mostly depends on ambient temp. If temps are below 60F, I don't have any coolant temp issues.

Above 60F, how quickly I get to 242F coolant depends on just how hot it is out (and obviously how hard I'm driving). 80F and below I can get 15min or so of ripping it and then I need to cool for a lap. >80F is 10min or so and the cool lap only buys me another hot lap before another cool lap.

At this point I think the issue is airflow to the radiator and any large IC that blocks it (Evo3 for me). So, F87source and I are thinking about going smaller IC and water injection for IAT control, and it should provide more clean air to the radiator. Won't know for sure until next spring/summer.

All the above is running E50 @ 480whp, water + wetter, 300V, MaxCool on, etc., and with F87source guidance I installed an E39 aux cooling pump inline to the oil/coolant exchanger, which hasn't bought me more cooling capacity/time, but it does seem to cool the car a little quicker once it gets hot.

How is your beast handling hot track days?

[F87source]

Originally Posted by ZM2

Hey! It mostly depends on ambient temp. If temps are below 60F, I don't have any coolant temp issues.

Above 60F, how quickly I get to 242F coolant depends on just how hot it is out (and obviously how hard I'm driving). 80F and below I can get 15min or so of ripping it and then I need to cool for a lap. >80F is 10min or so and the cool lap only buys me another hot lap before another cool lap.

At this point I think the issue is airflow to the radiator and any large IC that blocks it (Evo3 for me). So, F87source and I are thinking about going smaller IC and water injection for IAT control, and it should provide more clean air to the radiator. Won't know for sure until next spring/summer.

All the above is running E50 @ 480whp, water + wetter, 300V, MaxCool on, etc., and with F87source guidance I installed an E39 aux cooling pump inline to the oil/coolant exchanger, which hasn't bought me more cooling capacity/time, but it does seem to cool the car a little quicker once it gets hot.

How is your beast handling hot track days?

I just wanted to add, that with recent findings, I think the m235i aux water pump is fully retrofitable in terms of being bolt in pnp, but you will need to run a stand alone controller and set it up. After which you can either have it go fully automatic if you have the proper temp probes in place, or manual control with a dial.


At the end of the day I don't expect any performance gains from having the m235i setup over the e39 setup aside from being able to control pump speed. The e39 pump setup is full tilt once the car is on.

[F87source]

But yeah if any of you guys want to try some of my crazy ideas let me know and I will guide you through it. The more of us working on this issue the better, maybe we can actually tackle and solve it.

But the main thing is if some how we can get an ER style intercooler (the important part is it doesn't have that annoying step at the bottom that sits under the radiator) with even wider end tanks, that way we can slot in a full size s55 radiator behind the intercooler. This should completely solve the coolant issue once and forall, however I doubt any cooling company will ever tackle this.

I wonder if ECSTuning or CSF Cooling would ever be interested in doing something like this.

[-Eidos]

Originally Posted by ZM2

Hey! It mostly depends on ambient temp. If temps are below 60F, I don't have any coolant temp issues.

Above 60F, how quickly I get to 242F coolant depends on just how hot it is out (and obviously how hard I'm driving). 80F and below I can get 15min or so of ripping it and then I need to cool for a lap. >80F is 10min or so and the cool lap only buys me another hot lap before another cool lap.

At this point I think the issue is airflow to the radiator and any large IC that blocks it (Evo3 for me). So, F87source and I are thinking about going smaller IC and water injection for IAT control, and it should provide more clean air to the radiator. Won't know for sure until next spring/summer.

All the above is running E50 @ 480whp, water + wetter, 300V, MaxCool on, etc., and with F87source guidance I installed an E39 aux cooling pump inline to the oil/coolant exchanger, which hasn't bought me more cooling capacity/time, but it does seem to cool the car a little quicker once it gets hot.

How is your beast handling hot track days?

Gotcha, 60F seems to be about in line with what I'm seeing.

Here's 7-8 minutes of driving in session 3 at Auto Club Speedway on my lower boost map (Haven't dyno'd this but it feels like low to mid 500whp):

https://datazap.me/u/eidos/acs-sessi...0&data=2-3-4-5

Looks like coolant temps are peaking at 222F with an ambient temp of 63F.

Seems like in warmer weather 200TW tires might grease up and require a cooldown lap before or at the same time as when the coolant temps hit 242F. In SoCal we can see ambient temps of up to 110-120F on track, but I'm usually not in those conditions. Average temps are probably anywhere between 60-85F. We'll see as the weather gets warmer. I'll also go on map 3 next time once the Nostrum Stage 2 injectors are fully dialed.

[AmuroRay]

What IC are you running? Stock Radiator? Have you considered a higher capacity auxiliary radiator?

[-Eidos]

Originally Posted by AmuroRay

What IC are you running? Stock Radiator? Have you considered a higher capacity auxiliary radiator?

Wagner Evo 3 and just a CSF radiator. No upgrades to the oil cooler or aux radiator yet - may go with D088 when the time comes.

[F87source]

Originally Posted by AmuroRay

What IC are you running? Stock Radiator? Have you considered a higher capacity auxiliary radiator?

ZM2 has done all of that, coolant temps remain an issue.

[alwjmonster]

Originally Posted by ZM2

Hey! It mostly depends on ambient temp. If temps are below 60F, I don't have any coolant temp issues.

Above 60F, how quickly I get to 242F coolant depends on just how hot it is out (and obviously how hard I'm driving). 80F and below I can get 15min or so of ripping it and then I need to cool for a lap. >80F is 10min or so and the cool lap only buys me another hot lap before another cool lap.

At this point I think the issue is airflow to the radiator and any large IC that blocks it (Evo3 for me). So, F87source and I are thinking about going smaller IC and water injection for IAT control, and it should provide more clean air to the radiator. Won't know for sure until next spring/summer.

All the above is running E50 @ 480whp, water + wetter, 300V, MaxCool on, etc., and with F87source guidance I installed an E39 aux cooling pump inline to the oil/coolant exchanger, which hasn't bought me more cooling capacity/time, but it does seem to cool the car a little quicker once it gets hot.

How is your beast handling hot track days?

Wagner evo3 is too big, it blocks the already small radiator. Preferably to go for evo 2 ic + wmi will adequate for 480whp iat.

[alwjmonster]

Originally Posted by F87source

ZM2 has done all of that, coolant temps remain an issue.

I saw he said he’s running evo 3 intercooler which blocking clean air to the radiator.

[AmuroRay]

Originally Posted by alwjmonster

Wagner evo3 is too big, it blocks the already small radiator. Preferably to go for evo 2 ic + wmi will adequate for 480whp iat.

The Evo 2 is overpriced garbage even with WMI. I'm betting the CFS radiator is half the issue. On the F80* platform it performs worse than stock.

https://f80.bimmerpost.com/forums/sh....php?t=1760854

[ZM2]

Originally Posted by alwjmonster

Wagner evo3 is too big, it blocks the already small radiator. Preferably to go for evo 2 ic + wmi will adequate for 480whp iat.

Unfortunately I’ve had this issue for several years with many variations of power levels, ICs, and supporting hardware: https://f87.bimmerpost.com/forums/sh....php?t=1525790

IDK that going back to a smaller IC (still had coolant temp issues) with WMI (haven’t tried it, would keep IAT in check but may not help enough with engine temps) will cut it. But, that’s kind of where we’re headed.

So, what’s the best, smallest IC that impacts airflow to the radiator the least, that I could pair with WMI? I agree that the Evo2 isn’t good (tried it), but I need something small like that for the airflow/coolant temp issue. Hell, might even try the stock radiator with WMI.