Tips for a First Timer & Cooling issues

[Foda420]

So after 5 years of ownership, a good amount of modifications, and a crapload of money later, I finally got my girl on track! This was always the goal, but there was always something that came up, either in life or with the car and as someone who likes to go ham I wanted to make sure everything was in order first.

Knowing this, my best friend bought me a trackday for my birthday, giving me about 3 months to finish my prep in earnest and get to it. What I didn't know was that he was going to drive his Miata cross country to join me so we could do our first trackday together. Obviously we had a blast! We ran at Fontana Auto Club Speedway with Speedventures. Unfortunately the only instruction I got was lead follow during the 1st two sessions, I was all alone for sessions 3 & 4. Even still I managed to turn a 2:04.6 as my fastest lap, and I turned a 2:04.9 crossing the line in the pits when I pulled in to cool down. Any of you that know that track will know that I gave up a solid 3 seconds by doing that if not more. For comparison, the fastest timed lap of the day was a 1:54.xx laid down by a Cayman GT4 in a much faster run group. I don't have it on camera, but I did run down a B8S4, M2, and that same GT4, except driven by the owner's wife. The vid of my last 3 laps is below, any advice is greatly appreciated! I've spent the last few days replaying it all trying to figure out where I could be faster, and I have some ideas but would love to get outside opinions as well.



I'll spare you guys the long story but I've always been concerned with cooling in this car and I started with that before modding anything else 4 years ago. Currently I have a PWR 4 row radiator, Stewart WP, 88* thermostat, low temp fan switch, silicone hoses, brand new aux fan, spal puller fan, MM underpanel with baffle, and am running maybe slightly less than 50% coolant with 1.5 bottles of water wetter mixed in. The fan is wired so it comes on both settings and when I run the A/C. I had to keep one eye on my temps and had to cut a couple of my sessions short to try and save the motor. I also short shifted by 800 RPM's or so consistently to try and manage temps on track. Even still, I saw as high as 105*C coming off the track. Even though the track itself was around 115*F, I'm not sure I should've been running that hot. I know a lot of you have run much harder for longer in similar temps, any ideas on this? As another data point, I was hitting up to 97*C running through a canyon the day before around sunset. We weren't going fast as we had a large group and it was around 90*F outside.

[Vettett15]

I have a similar cooling setup but on a 328is.
Mishimoto 4 core
Mishimoto puller fan with fan controller taking temps straight from radiator
Stewart pump
70 deg c ish thermostat
Gallon of antifreeze, 1 bottle of water wetter and the rest water.

Haven't run it on the track yet but I've run it pretty hard on the street in 95 degree Florida afternoons. Hottest I could get it was after a hard run with the ac on running slow to minimize the flow thru the radiator. I could only get it up to 196ish which is about 4 degrees above the fan turn on temp. Normal driving on the road with the ac on with the car moving my electric fan doesn't even come on, as it doesn't even get it out of the 170s.... too cold in my opinion, thanks to my too low thermostat.

Here are some things I'd check:

How confident are you that all of the air is out of the system? I spent a lot of time bleeding mine using this method, https://youtu.be/nSTCBsuPr1I. Even after I got it pretty good I put an evacuation pump on it and it pulled even more air out. You'd have to go to a shop for that.

How are you reading your coolant temp? I'm using an obd2 Bluetooth reader.

On your puller fan do you have some sort of weather stripping or seal between the fan and radiator? I've seen alot of setups that do and it just pulls air from the gap and not thru the radiator as well as it could.

Have you cleaned your ac condenser? Can get clogged up which still restrict airflow to the radiator.

With your ac off, which I assume it is when you're on the track, what temp does your puller fan turn on? Do you have a fan controller?

[CoMZ302]

I was running about 210* at the track in traffic - pretty good but it could be better. I took out all the plastic shrouding around the radiator and hand made some aluminum pieces with rivets - my temps went down to 198 which is amazing at High Plains on July 4th weekend.

Look closely at your shrouding. Make sure all the air that comes in the grill and bumper is forced through the radiator. This matters more than people realize. The air will take the path of least resistance, which is any and all little holes it can find. Another trick is to use aluminum ducting take (lowes/HomeDepot) and seal up all the open holes (there's a lot!) from the inside of the radiator area - you'll want/need to remove the bumper to do this work.

[Foda420]

I have a similar cooling setup but on a 328is.
Mishimoto 4 core
Mishimoto puller fan with fan controller taking temps straight from radiator
Stewart pump
70 deg c ish thermostat
Gallon of antifreeze, 1 bottle of water wetter and the rest water.

Haven't run it on the track yet but I've run it pretty hard on the street in 95 degree Florida afternoons. Hottest I could get it was after a hard run with the ac on running slow to minimize the flow thru the radiator. I could only get it up to 196ish which is about 4 degrees above the fan turn on temp. Normal driving on the road with the ac on with the car moving my electric fan doesn't even come on, as it doesn't even get it out of the 170s.... too cold in my opinion, thanks to my too low thermostat.

Here are some things I'd check:

How confident are you that all of the air is out of the system? I spent a lot of time bleeding mine using this method, https://youtu.be/nSTCBsuPr1I. Even after I got it pretty good I put an evacuation pump on it and it pulled even more air out. You'd have to go to a shop for that.

How are you reading your coolant temp? I'm using an obd2 Bluetooth reader.

On your puller fan do you have some sort of weather stripping or seal between the fan and radiator? I've seen alot of setups that do and it just pulls air from the gap and not thru the radiator as well as it could.

Have you cleaned your ac condenser? Can get clogged up which still restrict airflow to the radiator.

With your ac off, which I assume it is when you're on the track, what temp does your puller fan turn on? Do you have a fan controller?

Your lower temps are definitely due to that thermostat. I thought about running one when I redid my system, but ultimately it was too low. From experience I can tell you the stock temp gauge gets to center when the DME reads about 77*C so the 70* thermostat has you running colder than the designed operating range. Also, it would be interesting to see if it really makes a difference once you're on track. At that point temps are high enough that it will constantly be open anyway.

I'm about 95% confident on the air being out of the system. I have a method that works pretty well but I did have to drain and refill the radiator the day before the track day so there's always that question in the back of my mind.

I'm also reading temps using a bluetooth OBD2 reader, pulling the data from wherever the DME pulls it from.

No weather stripping or seal on the fan. I had done something like it before and it really didn't make much difference. It is something to consider, however my puller fan is fairly offset on the radiator so it does not contact the WP nut.

I have not cleaned my condenser, that is a good idea, especially because I live near the beach and it's not uncommon for me to clean sand off the radiator cover & other parts of the bay when driving on windy days.

I don't have a controller for the fan other then turning my A/C on, which used to work wonders, but now causes temps to rise steadily though not quickly. The fan will kick on at about 90*C and run until it cools a degree or two. I believe the fan switch operates off a different sensor than what the bluetooth reader does so occasionally it won't change at all. With the fans running when parked, it won't go above 93*C. While driving I'll be anywhere from 89-94*C (190-201*F). Unfortunately, up until about a month ago I wasn't super concerned with the temps the car was running and wasn't really paying attention so I don't have much to compare to.

I was running about 210* at the track in traffic - pretty good but it could be better. I took out all the plastic shrouding around the radiator and hand made some aluminum pieces with rivets - my temps went down to 198 which is amazing at High Plains on July 4th weekend.

Look closely at your shrouding. Make sure all the air that comes in the grill and bumper is forced through the radiator. This matters more than people realize. The air will take the path of least resistance, which is any and all little holes it can find. Another trick is to use aluminum ducting take (lowes/HomeDepot) and seal up all the open holes (there's a lot!) from the inside of the radiator area - you'll want/need to remove the bumper to do this work.

This sounds like a lot of work but ultimately will most likely be what I have to do. Oh well LOL


From what I can tell researching over the past couple days, I was more or less where I should be, perhaps a little bit hotter, given the conditions I ran in. Trackside temps were 115*F, and we were 1000ft. above sea level. The highest temp I saw coming off track was 105*C, or 221*F. I was losing coolant out of the bleed screw on the stock expansion tank on track though. I have a brass bleeder screw and it seems they always eventually cause the bleeder hole to leak. Obviously this means the system was pressurized, but I think that's expected since it got over boiling. There was some but not much residual pressure in the lines after the car cooled, and there are some small drops of oil in the expansion tank. My HG may very well be close to failure, which would suck, but the car didn't really run like it at all. I think I'll play it safe and keep her off the track while temps are this high for now.

[aeronaut]

1st track day, or 1st track day with this car? Assuming 1st track day, I have 2 recommendations.
- Don't worry about lap times.
- Get time with an instructor in the car.

As far as cooling; FYI a lower temp thermostat does nothing to help lower max temperatures under any particular condition, it just takes a bit longer to get there. And on track, you'll get there quick.

Oil in the coolant? Pretty convincing that you need a new head gasket.

[Foda420]

1st track day, or 1st track day with this car? Assuming 1st track day, I have 2 recommendations.
- Don't worry about lap times.
- Get time with an instructor in the car.

As far as cooling; FYI a lower temp thermostat does nothing to help lower max temperatures under any particular condition, it just takes a bit longer to get there. And on track, you'll get there quick.

Oil in the coolant? Pretty convincing that you need a new head gasket.

1st track day (after many thousands of virtual laps over the last 20 years or so lol). I definitely want/need an instructor in the car next time, none were available for this and we weren't allowed to give ride alongs so I couldn't ask a faster driver to join.

I should know better than to pay attention to lap times but I had one small issue. The bimmer challenge time attack ran that track a month ago and I knew the times for the class I'd be in. I'm trying to compete in that next year so even being my 1st track day ever, I wanted to see how I stacked up lol. Winner of the class laid down a 1:54.xx in an E36 with similar power, 800#s less, semi slicks, and 20º cooler weather. I'm not sure I had ten seconds out there but I'm happy with how I did anyway.

And that's exactly what I was thinking with regard to the thermostat. Once on track it won't make a difference at all.

[CoMZ302]

From what I can tell researching over the past couple days, I was more or less where I should be, perhaps a little bit hotter, given the conditions I ran in.

Yes 210 is warm but not upsetting at all. Remember the boiling point of water is much higher under pressure.

Oil in the water is a real problem tho - get that checked out.

[olemiss540]

1st track day, or 1st track day with this car? Assuming 1st track day, I have 2 recommendations.
- Don't worry about lap times.
- Get time with an instructor in the car.

As far as cooling; FYI a lower temp thermostat does nothing to help lower max temperatures under any particular condition, it just takes a bit longer to get there. And on track, you'll get there quick.

Oil in the coolant? Pretty convincing that you need a new head gasket.

Keep in mind that watter wetter can cause a brown oily sheen in the overflow tank. Mine has consistently done this even after a full HG job.

The pressurized system once it sits overnight is for sure a tall tell sign though...

[hc1001]

I think your temps are fine. The oil you are seeing might be from the water wetter. I've had it before when using it and after i stopped, i didnt see any oil in the expansion tank anymore. Its been reported by a lot of redline water wetter users.

Its not boiling over since the system is pressurized up to 30psi via the tank cap. That raises the boiling point to ~250F for water.

Not sure why coolant is coming out of the bleeder screw. Maybe the tank needs replacing. Check the O-ring on the bleeder screw first.

[aeronaut]

1st track day (after many thousands of virtual laps over the last 20 years or so lol). I definitely want/need an instructor in the car next time, none were available for this and we weren't allowed to give ride alongs so I couldn't ask a faster driver to join.

I should know better than to pay attention to lap times but I had one small issue. The bimmer challenge time attack ran that track a month ago and I knew the times for the class I'd be in. I'm trying to compete in that next year so even being my 1st track day ever, I wanted to see how I stacked up lol. Winner of the class laid down a 1:54.xx in an E36 with similar power, 800#s less, semi slicks, and 20º cooler weather. I'm not sure I had ten seconds out there but I'm happy with how I did anyway.

And that's exactly what I was thinking with regard to the thermostat. Once on track it won't make a difference at all.

Excellent!
Just be careful of chasing times before you get the experience you need. Chasing times before you're at the advanced level can cause you to learn bad habits.

[Foda420]

I think your temps are fine. The oil you are seeing might be from the water wetter. I've had it before when using it and after i stopped, i didnt see any oil in the expansion tank anymore. Its been reported by a lot of redline water wetter users.

Its not boiling over since the system is pressurized up to 30psi via the tank cap. That raises the boiling point to ~250F for water.

Not sure why coolant is coming out of the bleeder screw. Maybe the tank needs replacing. Check the O-ring on the bleeder screw first.

I'm glad you think so lol! I hadn't heard about water wetter leaving an oily residue/drops before the posts on this thread so that's a bit of a relief.

I've had the brass bleeder screw for a long time, across a few different expansion tanks, and it always seems to leak at least a little. Checking the o- ring is a good idea, I'll definitely do that. I've also been thinking lately that maybe the plastic expands at a different rate than the brass and that allows coolant by?

I haven't posted in a bit because I wanted to drive the car and test if it remained pressurized. I put about 30 miles on it, with a coupe high rpm pulls for good measure. Parked it overnight and checked the cap the next morning. No pressure release at all. Inside the cap looks like the pic attached (let me know if you guys can't see it). Most of the residue is now lining the inside of the expansion tank. There were drops before but they seem to have dissipated.

Excellent!
Just be careful of chasing times before you get the experience you need. Chasing times before you're at the advanced level can cause you to learn bad habits.

Thanks man, I'll keep that in mind! I hope to get a few more days under my belt before I start chasing times next year.

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[olemiss540]

Looks like water wetter to me.....

[DocWyte]

Really hard to replicate track conditions with street driving. Many cars are fine in street driving but the next time they hit the track they have a catastrophic failure.

[Foda420]

Looks like water wetter to me.....

Me too but I'll be keeping an eye on it!

Really hard to replicate track conditions with street driving. Many cars are fine in street driving but the next time they hit the track they have a catastrophic failure.

This is very true and I do NOT try to replicate track conditions on the street. That said, I'm waiting to replace my front swaybar links so I can go do a couple "romantic" cruises through the local canyons and see how she sits the day after that. Closest one is about 25 miles one way so she'll be plenty warm by the time I get her home.