Question for Track Cooling Setup Beginner/INT HPDE Use

finnporter

New Member
Jan 9, 2021
2
2
0
Hi guys,

I'm coming from a 350z setup based in California, moved to New York area and now have a 2008 335i 6AT. I only have 2 HPDE events at Willow Springs on the west coast under my belt. I haven't done much cooling mods previously since I've only tracked during the Spring or Fall seasons in the 350z, but I keep seeing threads about limp mode on various forums for the N54 platform and have been closing monitoring this thread https://www.spoolstreet.com/threads...re-your-temps-during-extended-track-use.4352/

However, the users I see here look like they track consistently year-round or may be too advanced for my skill level. What would be a realistic** cooling setup for annual 2 to 3 track events with the use case below? I want to at least complete continuous (3) to (4) 20 min sessions throughout the day. Appreciate any advice and thank you guys beforehand.

Car: 2008 335i
Transmission: 6AT
Track Tires: Performance Street Tires, probably summer type, brand interchangeable, probably won't be able to afford R compound consumables even if my skill level requires it
Aero: Stock
Brakes: Upgraded pads and rotors w/ DOT4, no goal for front BBK setup as of now. Might upgrade for looks, but for consistent track/canyon cruising consumables might be too high for me
Power Goals: 350whp - 380whp via FBO, willing to de-tune further
Gas: 93 pump gas
Suspension: Digressive coilovers + M3 arms
Drivetrain: 1.5 LSD
Tuning: MHD + XHP
Driver Mod: Non-competitive beginner, goal is to be in whatever equivalent intermediate class for fun

Track that I'm interested in: Watkins Glen International
Fall Season High Temp: 70F - 80F, humidity, 65% to 80%

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I see that people have recommended an auxiliary radiator, secondary oil cooler, and transmission coolers. Would these off the shelf hardware options be viable for my use, assuming the software is tailored?
A. Scenario 1
1) 335IS Auxiliary Radiator w/ OEM Primary Radiator - would this be enough to cool my trans and coolant?
2) Hard Motorsports or FTP Motorsports secondary oil cooler, I have a stock oil cooler

B. Scenario 2
1) CSF Primary Radiator for Automatic
2) BMS Trans Cooler
3) Secondary oil cooler

Again, thank you guys for any input.
 

Illsic_Design

Specialist
Feb 2, 2018
56
25
0
Sac, Nor-Cal
Ride
09 335i
I'd track the car and then address it when the time comes. A beginner to tracking will not have issues with the cooling system unless you are really hard on the car

Then I'd go CSF radiator, then aux rad setup, then oil cooler setup
 
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Asbjorn

Lieutenant
Mar 10, 2018
810
550
0
European, based in China
Ride
Z4 N54 DCT
I spent more than one year testing different cooling setups on track in 2019, documenting everything here on spoolstreet. The main conclusion was that the stock radiator of the N54/N55 is way too small for track use in hot and humid climates. Not in terms of thickness, but in terms of area. That was addressed with the S55, and the best thing that can be done is to copy that setup with aux radiators. I cant believe there are still people in here recommending the expensive CSF radiator which offers no increase in radiator area whatsoever. Clean your stock radiator instead. Save money. Done.

So let me repeat: Don't go CSF radiator, it does not help, not at all. You need more cooling area if you want better cooling performance. So do not go for scenario 2. Scenario 1 is your best option, and no it wont be enough to keep your car cool under all circumstances, even if you go back to stock power.

My conclusion was and is that you wont be able to do 20min sessions flat out in any kind of hot/humid climate if you want to keep water temps below 110C (the stock limit is 117C, but I prefer to keep it below 110C). You will end up doing one hot lap followed by one cool down lap and then repeat.

Also dont get a BBK. Save the money and get real track pads instead. The expensive type. Not just upgraded pads. Real track pads that are terrible, noisy and dusty on the street.

And finally, you mention that you cant afford this and that. Please do consider another sport. Track days are more expensive than most people realize, and the risk of crashing is always the highest in the beginning. You could become an intermediate driver though lots of gokarting instead.

Also there is no such thing as different skill levels requiring different tires. It is about just as hard to set a perfect lap on street tires as it is on semi-slicks or slicks, it just wont produce the same impressive laptimes. And in the end you just wear yourself and the car out much faster with slicks. Also do not ignore one of the largest hidden issues with the N54 on track - loss of oil pressure through left hand corners. People dont realize the issue is there because the N54 does not come with an oil pressure sensor.

Get something with an S55 and all these problems are gone. Only stick with the N54 if you are willing to invest... alot...
 

finnporter

New Member
Jan 9, 2021
2
2
0
@Asbjorn Thanks for the insight! Your post really summarized what I've been researching for my use case on this forum, E90Post, and on YouTube. In regards to what you've suggested, I'll be on the lookout for a PPK aux radiator, keep my track sessions to relatively colder days, real track pads, and just have somewhat competitive fun which is my goal anyway. I've also seen Adam LZ, a YouTuber that happens to have a N54, mimic what you mentioned about 1 hot lap and 1 cool lap during his track sessions with the car. I don't mind doing this for my use case, but for some people it's most likely counterproductive.

Interesting on the loss of oil pressure. I haven't seen this issue when I look up "track prep" or related threads on the forums, but briefly seen it as a topic in track related threads. I'm hoping my lack of aero, street tires, and skill level won't require an accusump or baffles anytime soon. I'll look into installing an oil pressure gauge and sensor adapter. I've also seen baffles from VAC and Bimmerworld, but I still see issues with VAC and can't find reviews of the Bimmerworld one.

In regards to S55, I'll stick with the N54 and run with the cards I've been dealt with. These cars will be the new Nissan 240sx/Silvia soon, so it'll only be a matter of time before someone with bankroll will solve these issues. I got the car for $8k USD and the price will only bottom out further.

For go karting, that's actually a great suggestion that I've been looking into closely -- both indoor and outdoor. I live in NYC or basically the equivalent of a megacity, so buying a prepped go kart and the logistics that go with it might not be feasible for me, but I'm down for rentals.

Again, thanks for the insight.
 

Asbjorn

Lieutenant
Mar 10, 2018
810
550
0
European, based in China
Ride
Z4 N54 DCT
A baffle wont solve the oil pressure issue. The problem is mainly there when trail braking into left hand turns. It also happens in long braking zones. Most people are not aware because they dont measure oil pressure. Suddenly the rod bearings just go. Its the same on the N55. Again look at what they did on the S55 and M2 N55. Thats the solution, and the GTS goes even further. Other than that, the only thing that is known to work is the accusump.

I used to run an oil pressure gauge in mine. Now I just run a loud siren connected to an oil pressure switch adjusted to open at 70C oil temp idle oil pressure, whatever that is. I only turn it on at the track as it sounds at idle which is annoying on the street. It serves two purposes. 1) If an oil line ever bursts, I will hear a siren. 2) I can hear how bad a given track + tire combination is, and avoid it. I also try not to got WOT when the siren sounds.

Needless to say, I will be doing much more go karting this year myself haha
 

amg6975

Corporal
Oct 27, 2019
235
148
0
Ride
2012 135, 2005 ZHP, 2009 fJCW
Hey, welcome to the area! Are you planning on running with GVC BMWCCA? If so find an S65 swapped 1 series and say hi, I'll be down at all the events this year. We also have an event at the NYST in May if you want to run there too!

As a 135 owner with lots of experience at WGI you'll want to address brakes and cooling and then send it! Cooling is easy, you can just do a cool down lap every now and then but you'll want track pads, high temp fluid, and make sure your lines are newish.

M3 control arms and stiff or solid rear subframe mounts should be your first suspension components.

Oh and you definitely won't want to rock down there with any sort of tune, so much of the lap is WOT you'll be overheating by turn 9 of your first lap.
 
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