Dirty Howie

Yesterday was my first track day since almost melting my tranny/engine etc and deciding to cool things down. I already had an external tranny cooler. I added the Dewitts radiator with internal EOC.

Yesterdays track was WSIR which is higher speed/less technical than BW which caused numerous coolant warnings. The ambient temps were 50 to 75 by the end of the day.

First sessions:
Coolant.....205-215
Tranny......215
Oil............255

Last sessions:
Coolant......225
Tranny.......225
Oil.............270

The 270 oil was the end of the last session...that was the highest it ever got. This is down from about 290-295 on same track.

The coolant seems good I think for ***** out at the track and is within normal specs anyways. I'm not sure but I think coolant was like 250 before.

The tranny temp seemed to follow the coolant even though I have an external cooler. This temp did not seem to drop much 5 degrees at the most....even though daily driving my tranny temps now are MUCH lower.

I will be going to a slower more technical track next month and will post these result too. If temps stay here I will be happy.....

Drive line is not stock.......A4-FLP level IV/TC/3.42


DH

0Tom@Dewitt

Thanks for the numbers! What do you use for coolant or is it straight water?

Dirty Howie

Tom

Glad you saw this post I was going to call you and give you the details tomarrow from work.

I'm using stock 50/50 coolant and water.

What is your impression of these temps?? And how do you predict the more technical track outcomes next month

BTW: Daily driver numbers are:
Coolant: 172-178
Tranny: 150-160
Oil: 192-202


DH

0Tom@Dewitt

They look pretty good. It seems the oil is running about 40 degrees over the coolant. When the ambient temps start to go up these numbers may increase as well. You might want to lower the coolant/water ratio to 30/70 and wetter water to help with inhibitor. Since things can't freeze in the hot summer, we don't need 20 below protection. Just make sure you use distilled water.

Dirty Howie

First of all I am in So. Cal. Lowest temps I ever see are 35-40.

How much cooler do you think the 30/70 mix will provide and how much Water Wetter if any do I need.

May be I can just drain a couple of gallons from the radiator before track days and replace with distilled water. Then after the track event replace with coolant.

I sure hope my oil doesn't get too much higher.......


DH

0Tom@Dewitt

Water cools better than anything on earth. So 100% is the best and if you don't mind having two batches of coolant, you could change out the whole thing before racing. With 100% water you will see about a 20 degree drop. Some racing events will not allow you to run coolant at all because any spills on the black top is difficult to clean up and it's slippery. I'm not a big believer in weter water, but they claim it has some inhibitor properties and it can't hurt to have some when running straight water.

Dirty Howie

Unless I have missed it ..... I wonder why no one talks about this. If my car runs much hotter at the next event I will definately look into swapping out to mostly water for track. Thanks for this info....


DH

ZR1 MK

Most people run a unnecessary 50% mix even when they live in cold climates. Only use a much as necessary for your area.
A 10% mix antifreeze for anti corrosion and lubrication with 1 or 2 bottles of watter wetter is recommended.

95jersey

I wanted to provide an update on my results on the DeWitt EOC. I ran 2 events (Summit Point and Pocono). Both days were about 65-75F, so the real test is yet to come, but I was definately amazed at how cool my temps ran as compared to last year.

My water temp always stayed below 200. They seemed to hang in the mid 190's. The big news is the oil temp. In the same weather last year, I would easily run about 240 - 250F oil temps. I never broke 206F

So far so good! If it works this well in the summer, we definately have a winner, especially when your several hundred cheaper than your competitors.

Dirty Howie

Your results are certainly different than mine !!!!!!! There may be some track differences and ambient temp defferences as well.

I suspect you have a MN6 where as I have an A4 with a converter. So I will run higher RPM than you. Which will result in higher oil temps. My coolant may be higher than yours as well since I have hotter oil and trans fluid running thru it.

Are you running 50/50 water and coolant?????????

What are your normal driving temps ???? We can compare to mine posted above.


DH

0Tom@Dewitt

Those sound closer to what I'd expect.

T.C.M. are you reading this?

Dirty Howie

Tom

Why do you think my oil temp would be so much higher (50-60 degrees) than 95jersey at the track ??


DH

Rob's 73

Those numbers sound great. I won't be tracking my car until 15 Jun at VIR. I'll post results.

Tom

Did you every receive my adapter block back? I have the insurance papers on my desk. Just want to know if I can throw them away.

Thanks

Rob

Dr Chill

There's something wrong here. When I ran at ambient temps like this with the car stock, my coolant ran around 240 and oil 290-300 and after the DRM combo unit, runs 225/270 max. Those temps only vary by a few degrees even in summer heat in So FL. These numbers are almost identical to all the other C5's running with the various clubs I participate in. The low temps you quote suggest your temp sensors are not accurate or you don't push the car very hard. Those numbers suggest you don't need additional cooling other than from the stock rad without oil cooler.

95jersey

I will try and clarify. First my normal driving temps are very low. In stop and go traffic with the DeWitt EOC AND a 160F thermostat with fans set at 190F...ambient around 75F, I run coolant temps about 175-180, with oil temps about 180 as well. I rarely ever see the temps ever get high enough to warrant the fans (190F).

The temps depend on the track, amount of shifting, RPM level and outside ambient. On the day mentioned the outside temps was between 65-70 with very little humidity (if that makes a difference). Now while my car has hit 290F oil temps without the DeWitt EOC, that was only on a very hot day, fast course and long sessions. Before the cooler I was running (on a hot day) between 265-285. On a cool day I would run between 240-265ish. My water temps were always on the low side compared to the oil, but on a hot day I might see 210 - 220'ish, usually they were under that temp.

Every car is different, but I rarely hit 300F oil without the EOC. I think 1 time I came close and I shut her down.

I couldn't beleive it either, but I was watching the temps at the very end of 20 minute session. This was a tight course and I did very little shifting. I was in 3rd 98% of the time which might have had something to do with it.

Rob's 73

I agree that you may have sensor issues. With my Dewitts EOC sitting idle in traffic in 70-80 heat, my water temps have hit 220. I have the stock stat and programming on the fans. It does take about twice as long as it did before to hit 220. I am sure the fans could keep the temps down but you are saying that your fans aren't even kicking in.

95jersey

I am sure I have no sensor issues. I would agree that even with the Dewitt if you have the stock thermostat and programming you would still see 220 as that is what the car is programed to run at. You have to understand, I am running the lowest possible thermostat (160), which means once the car is warmed up, it runs wide open. I run 60% water 40% anti-freeze along with Redline Water Wetter, which all helps out. I also have my fans set to come on at 190, all this in addition to the DeWitt EOC.

I am telling you the car runs so cool, I am wondering if it is too cool.

Dirty Howie

I ran the EXACT SAME temps as you last time at the track.....see my posts above.

Coolant: 225
Oil: 270


DH

Dirty Howie

AAAHHHHH !!!!!

Guess you didn't see my post above where I asked what coolant/water ratio you were running. I am going to drop mine from 50/50 to 70/30 with Water Wetter per TOM'S reccomendation

I also have a 160 stat. My DD temps as stated above are:

Oil: 192-198
Coolant: 172-176
Tranny: 140-160

These temps will go up a little with spirited driving but stay way below stock temps now.

I think you running only 20 minute session and almost entirely in 3rd gear makes a BIG difference.

Be interested to see your temp results on a course where you are getting your RPM up and session longer. My temps were at the END of 30 minute session.


DH

0Randy@DRM

Dr. Chill,
That is the highest temps I have heard on our setup. You must be really running the car hard!!! Big motor?

Randy