Overheating?

[DrSeuss]

Does anybody have any overheating problems when they autox? When I climbed in for my 4th run (last) after my co-driver, I noticed that my temperature was about at 1 o'clock. It normally sits around 11 o'clock. I cranked up my heater to try and dissipate a little more heat until my run started which helped a litte. The temperatures were unusally cool for June (70's). Our normal summer temperatures are up in the 90's so I'm a little concerned about overheating.

I left the car on between runs because by the time we changed the numbers, checked tire pressures, and swaped drivers, we only had a few minutes left before we were up again. Should I just shut if off after we return to grid?

BTW watching all those autox vids are great. Your lots are huge. It makes the WDCR lot look like a postage stamp.

[seank]

I don't know about z4m's and autox, but I do know that my track car gets hot (or over heat) during 2 things: idling and running at 8000 rpms. You were doing both. I would turn it off, unless you are having starting issues when hot.

[Blind32]

If you do turn it off, leave the key clicked on so the fan continues to run and noooooo parking brake.

[kklin]

Originally Posted by DrSeuss

Does anybody have any overheating problems when they autox? When I climbed in for my 4th run (last) after my co-driver, I noticed that my temperature was about at 1 o'clock. It normally sits around 11 o'clock. I cranked up my heater to try and dissipate a little more heat until my run started which helped a litte. The temperatures were unusally cool for June (70's). Our normal summer temperatures are up in the 90's so I'm a little concerned about overheating.

I left the car on between runs because by the time we changed the numbers, checked tire pressures, and swaped drivers, we only had a few minutes left before we were up again. Should I just shut if off after we return to grid?

BTW watching all those autox vids are great. Your lots are huge. It makes the WDCR lot look like a postage stamp.

I haven't noticed temps when I co-drive with my son. I usually open the hood between runs. A few weeks ago though I did notice the Star Specs (my first season on them) got a bit greasy.

Come to Citizen's Bank Park this Sunday where we combine lots for nice runs - http://www.phillyscca.com/forum/view...php?f=8&t=7417

[The HACK]

One o'clock position on the oil temp gauge equates to ~260 degrees in oil temp, well within the normal operating temp.

You want to talk overheating? 135i and 335i on track typically see anywhere from 270-315 degrees oil temp. That would leave it pegged squarely in the RED zone on our gauge.

The hottest I've seen is 2 years ago at Buttonwillow where ambient temperature was 116 degrees, I saw my oil temp get up to ~275. And even at those type of temps, it's still quite a bit to go to get to ~320 when oil start to lose some of its rated weight and start to thin out, and ~380 when they start to boil (although I wouldn't want to operate anywhere near 300 degrees for more than a few minutes).

[iPhoneEngineer]

I'm expecting weather over 100ºF for both days of my upcoming track weekend, and am a bit concerned since my car is boosted by 8PSI on stock compression. It should be a pretty harsh environment for the motor and I want to make sure not to get it too hot, particularly in the context of the supercharger kit. I'll be running 95 to 100 octane fuel to avoid knock.

Between runs I plan to lift the hood, of course--but would it be best to leave the car running to circulate the fluids (while also generating more heat from combustion), or shut it down?

[Kgolf31]

Originally Posted by Blind32

If you do turn it off, leave the key clicked on so the fan continues to run and noooooo parking brake.

You fan runs continuously if the oil is still hot. Happens on my car multiple times...it will go at it until it reaches the 11 o'clock position.

OP - Yes I'm always over the 12 o'clock position when I auto-cross. It's unavoidable. What else do you expect when you run the car hard for 45-60 seconds with little to no air flow into the engine? It will raise naturally.

Last time I was out, it was a 95*F day. The oil was around 1-1:30 o'clock and held there. Between runs I opened the engine bay, and kept the engine running while I sprayed my tires.

Looking at a normal E90 car, their operating oil temp is around 270*F. Of course they are running different oil, but you can see we have plenty of room to move, as the Hack said

[iPhoneEngineer]

Originally Posted by Kgolf31

Between runs I opened the engine bay, and kept the engine running while I sprayed my tires.

Looking at a normal E90 car, their operating oil temp is around 270*F. Of course they are running different oil, but you can see we have plenty of room to move, as the Hack said

Interesting, you mean take a water spray bottle to the tires? I hadn't heard of that technique--really valuable?

I'm pretty sure the E90 M3 uses the same 10W-60 oil, but maybe you mean a 335i or something. Indeed I bet my car will blow right past the 210º halfway mark due to the supercharger and hot weather...just wondering at which point I should give it mercy and back off, even if the run isn't done.

[Kgolf31]

Originally Posted by iPhoneEngineer

Interesting, you mean take a water spray bottle to the tires? I hadn't heard of that technique--really valuable?

I'm pretty sure the E90 M3 uses the same 10W-60 oil, but maybe you mean a 335i or something. Indeed I bet my car will blow right past the 210º halfway mark due to the supercharger and hot weather...just wondering at which point I should give it mercy and back off, even if the run isn't done.

I'm talking about a standard 335i

And yes...a tire sprayer is your best friend on hot days. I run hankook RS3s, and while they maintain heat well, there is a point where they can't handle the heat anymore and become greasy and lose grip.

This is where you use cold water to cool the tire and avoid this grease over point. You need to spray your tires early in your heats though...and carefully modulate how much you spray so you let the tires get to temp without over cooling them.

Make sense?

[SmartBastard]

On a track I get up to 125C (257F). You don't have to worry if you are under 145C (293F).

[Beedub]

absolutely nothing wrong with getting your oil upto the 1 oclock mark, just keep an eye on it but i generally LIKE to see the cooling system pushed alittle to see how it copes and also the oil we have in our cars are more than coping with the temp your putting into it..... keep an eye on this, respect the car and give it good cool down and if anything your doing it good imo......

[Trev]

OP: +1 on oil temps in the 12 & 1 o'clock positions are well within normal specs for our fancy TWS msport oil.
My concern wasn't on that level of heat but whether the ECU retards ignition at higher temps. Therefore for 70F+ ambient days after tires are upto temp I use the garden sprayer on radiator & tires.

BTW to answer your query to KGolf yep spraying down tires, at the right time, does work. Note "At the right time". Tires must be upto temp & should be done immediately after run. Idea is for water to have evaporated off prior to next run.

In all honesty don't worry about it until your getting upto the sharp end of the field. It just add's another layer of complexity to your driver swappage (Number swap, Tyre pressures, Tyre temps, Spray down Tyres & Rad, Pull cone from underside "Doh!")

[Kgolf31]

Originally Posted by Trev

BTW to answer your query to KGolf yep spraying down tires, at the right time, does work. Note "At the right time". Tires must be upto temp & should be done immediately after run. Idea is for water to have evaporated off prior to next run.

The right time starts at the beginning of your runs. If you wait til you get greasy, you will never get the tires back down to normal temp.

The reason being, is that the metal bands inside the tire get extremely hot. In order to keep them within temp, you need to keep them cool from the gecko.

Once they are past their temp limit, spraying water on the tire is a waste. The bands will soak the water instantly and not cool it down at all.

The more tread you have, the more you have to spray earlier. It's a tricky thing to get use to, as I said before.

[AriuSen]

so does this mean the z4m doesnt need a bigger oil cooler?
in summer time when track is 90 degrees, is the z4m prone to overheat?
Beucase when I had my e92, never had overheat problems, but I see some e46 people upgrading oil cooler.