Tracking car hard in hot climate

[BTB]

I've been running a Bimmerworld/C&R radiator with no issues on track but will get the needle rising around town with A/C on at low speed (Austin, TX 100+ F). Do most people replace A/C condenser at higher miles as well? I'm at 215k miles on chassis, about 57k miles on this aluminum radiator. At this point I don't like to drive the car around town if its 90+ F outside. Not sure if others are able to blast A/C around town in hot climates but would like to address this if possible. Have OE oil cooler (few years old) and a Mishimoto electric fan

[samthejam]

dreamdrivedrift Have you tried it in warmer weather?

[CrisSilberGrau]

Wild to me that every person that's been with this platform and gone there and back with it all say don't go away from OEM radiator and still ppl do... Now we're also at the point where OEM radiators are not from Modine anymore which is sad, not sure if anyone has metered use with the new Modine "owner company" (name transfer or whatever.

In terms of oil temps, new OEM oil cooler and surrounding hardware new OEM is known to have drastic improvements on lowering temps. You have a 24 year old platform with 24 years of use that many times was not you at the wheel or underneath it to care for it. I see oil coolers as the only real improvement over OEM and id never give my money to CSF. d088 is where id go for a like OEM replacement with increased capacity and a lower weight penalty.

The only other options that I've seen on cars that see dedicated track duty (this means wheel to wheel race cars not time attack), is PWR. These cars do not have AC or anything obstructing the frontal area of the radiator.

[eacmen]

It looks like it was the CSF radiator. I put an OE BMW radiator in with 50/50 water/coolant + water wetter, and tracked it all weekend. Granted, it was cooler, ambient temps in 40s-50s F, but water temps totally stable in the 170s, never needed nurse the car at all.

I made the same switch CSF to OE and been much happier. I cant believe these CSF units still being sold.

[dreamdrivedrift]

It looks like it was the CSF radiator. I put an OE BMW radiator in with 50/50 water/coolant + water wetter, and tracked it all weekend. Granted, it was cooler, ambient temps in 40s-50s F, but water temps totally stable in the 170s, never needed nurse the car at all.

[bigjae46]

Yes the whole area is quite blocked off
I am glad at least I don't have aux fan, but even the N15 bracket the SPAL fan is mounted on blocks quite a bit of airflow on the rear side of the rad
Last, there is no exit for airflow on this car. I can imagine proper ducting behind the rad or at least more venting would help dramatically
Appreciate your input though. Can AC condenser be removed from behind or do I need to pull the front end off? I don't have an aux pusher fan.

I think you need to pull the radiator out.

[dreamdrivedrift]

I'd start with a new AC condenser and go back to a stock radiator. Without more airflow, a thicker radiator will likely not improve cooling at speed.

Look at the stock aero devices...there's a lot more than you'd think. I'd make sure you have the heat shielding over the headers installed. Also JUST learned that your windshield cowl plays a role in cooling. For example, deleting the cabin air filter housing will increase air pressure under the hood which stalls the flow through the radiator.

Yes the whole area is quite blocked off
I am glad at least I don't have aux fan, but even the N15 bracket the SPAL fan is mounted on blocks quite a bit of airflow on the rear side of the rad
Last, there is no exit for airflow on this car. I can imagine proper ducting behind the rad or at least more venting would help dramatically
Appreciate your input though. Can AC condenser be removed from behind or do I need to pull the front end off? I don't have an aux pusher fan.

[bigjae46]

I'd start with a new AC condenser and go back to a stock radiator. Without more airflow, a thicker radiator will likely not improve cooling at speed.

Look at the stock aero devices...there's a lot more than you'd think. I'd make sure you have the heat shielding over the headers installed. Also JUST learned that your windshield cowl plays a role in cooling. For example, deleting the cabin air filter housing will increase air pressure under the hood which stalls the flow through the radiator.

[dreamdrivedrift]

Bumping an old thread because I am having overheating issues at track.

Setup:
-new OE WP
-new OE thermostat
-50/50 (I think?) BMW coolant
-new CSF radiator
-SPAL puller on N15 bracket
-no aux fan

Situation:
I'd get 1, maximum 2 laps out of the car at Laguna at full tilt, ambient temps in 80s, before water temps would spike 220-230+. Had to short shift 6-6.5k to manage the heat and keep it in the 200s-210s


Reading here, it seems that the consensus is this is probably due to the CSF radiator?
I was planning on replacing it with a DO88 radiator. Reading this thread is giving me second thoughts.
While I'm there, will also plan to put in water wetter and clean out the AC condenser.

Any other suggestions to look into?

[eacmen]

Right now I have my gauges go into warning territory at 200F, engine outlet temp, and go red at 210F.

What on track coolant temps do you guys stop pushing at? Last event I saw 210F and did a cooldown lap.

[S14]

Would it be a good idea to throw in a few gallons of 100+ octane (unleaded) in the interest of ping prevention? Any downsides, besides being a waste of money?

When I was dealing with overheating in Colorado, putting a 1/2 tank of 100 octane extended the time it took for the car to overheat. This made me consider the tune's timing might be too aggressive.

[wahsm]

Are you tracking your car in 100 degree temperatures?

I have yes, handled it well. The stock one was old so could be similar in performance, but additional capacity and all aluminum housing was a bonus for me.

[zzyzx85]

So long as your car is correctly tuned for pump, that's just lighting money on fire.

the sound of that money burning is pretty great though 🤣

[Obioban]

Would it be a good idea to throw in a few gallons of 100+ octane (unleaded) in the interest of ping prevention? Any downsides, besides being a waste of money?

So long as your car is correctly tuned for pump, that's just lighting money on fire.

[EthanolTurbo]

Would it be a good idea to throw in a few gallons of 100+ octane (unleaded) in the interest of ping prevention? Any downsides, besides being a waste of money?

Would probably be much easier/more convenient to throw in 2-3 gallons of E85. It will give about the same amount of knock protection/octane boost.