Dirty Howie

As some of you know I have been struggling with cooling issues and trying to road race my A4. It has a small torque converter and built tranny (well...I guess I unbuilt it ). Also have big radiator and coolers. EOC in radiator. TOC separate cooler.

I guess I finally abused it enough that the tranny gave it up after last weekends racing.....

I am looking for any other members who are tracking an A4 so we can compare notes.......temps, cooling strategies etc.

I have to put in another tranny and would like to make this one last longer


DH

Slalom4me

Sorry to hear about that.

How many of the prep items mentioned in the earlier thread(s) were
you able to put into place before the event and what were conditions
like at the track?

I have an A4 but it is in a C4 so there is not a direct correlation. Also,
my 'Solo I'-like events are shorter than what I understand is the norm
for HPDE. Finally, temps here do not reach the extremes you were
anticipating for last weekend.

I have a sensor to add trans temp logging to my G2X, but it
remains to be installed due to some other priorities. If you do
not already have one, I'd suggest adding a gauge as part of the
work during the repairs.

.

Slalom4me

A link to a recent thread on ATF Fluid temperature
in C4 Tech.

What is the normal operating temp for a Auto Trans

.

AU N EGL

Manual Trans with coolers.

Many auto-x guys when they come over to HPDEs find the cars run much hotter on a 30 min session then it does for 45 sec - 1:30 run.

Slalom4me

By 'Solo I'-like, I mean 6 laps on a 2 mi (3.2 km) road course consisting
of 4 timed laps with a warm-up lap before and a cool down lap after.

Still not a 30 minute HPDE session in 100ºF but a little more rigorous than
the usual Solo II parking lot affair.

.

Dirty Howie

I only got some of my exhaust wrapped where it nears the tranny. I did not get the larger tranny pan or bigger (or second) cooler.

The temps were 107 on my last session.

Since it didn't break down at the track or even on the way home ...... but the next day at 70mph on the frwy.....I assume its a cumlative breakdown.....not just some thing specific to this last track day. I actually was watching the tranny temp and when it got to 245 I got off the track.....where as there were a couple of track days where I got the tranny temp warning. But that is only a few degrees more at 258 I think.


DH

Dirty Howie

Thanks for the link......

My car is a daily driver ...... 500 miles per week. It now has 72K on the odometer. I'm not sure how old the tranny is as I bought it used. I think I have had it for about 8-9 months and about 8 track days.

Normal tranny temp is 147-185 (the high when its 100+ ambient)

So its only a very small fraction of use where it sees abusive temps....but I guess its enough


DH

Dirty Howie

........I may move to ICELAND


DH

DALE C

If any one can help you it would be Rodney at RPM transmission he does all the automatics for my shop and he is a forum vendor. It is going to be hard to make the auto live long running HPDE events.
www.rpmtransmissions.com

Dirty Howie

Thanks......I have heard lots of good about him....and I tried to get a hold of him yesterday but I guess he closed his shop for the long weekend.

Do you have one in stock ????


DH

zeusoftexas

I have run mine at TWS in July and Aug(over a 100F)and both times the tranny got up to around 255F the last lap (30minutes). I have a small eral's cooler. I run in December it's 230F. I have stock tranny and stock converter. By the end of the cool down lap the tranny is 210-200F. It runs around 170-180 on the street.

Fluid looks red and clean.

I'm going to wrap my pipes and put a bigger cooler on before I go again.

Stay with a stock converter?

Dirty Howie

Well mine got that hot WITH a cooler. A couple more degrees and you would have seen the CEL. You are lucky so far ..... hope it doesn't die like mine. I also have a 2400 converter.......


DH

XPC5R

I have similar power and the same stall converter in my car. Same temp issues, even while autocrossing (2 drivers, maybe 3-5 minutes between runs). The tough part for this car is after the hot, WOT run, you pull back into grid, and have to sit with no moving airflow. No real cool off lap is available.

My original setup: Stock radiator, stock trans cooler not used. Large B&M trans cooler with its own fan (mounted in the rear of the car, behind the diff) I saw 250 degrees it hot weather, on long courses, and the trans would not cool off at idle. Things improved when I ran the fluid through the stock oil/water cooler in the radiator, then to the rear B&M cooler. Temps now stay down in the 210-220 range. I'm planning on relocating the cooler into clean airflow in the nose next.

I've tried a good size Earls/Setrab cooler in the side vents (Z06 rear brake ducts) but had the same issue with cooling at idle - limited airflow.

The downside of that routing is that you can't get below coolant temp (around 180-200 degrees in my car). A cool solution (no pun intended) might be a thermostatically controlled bypass that bypasses the radiator at high coolant temps.

One thing to keep in mind, if you see trans temp that high, a refresh of the trans fluid is cheap insurance.

MattB

Sorry to hear about your tranny

I'm afraid for mine as well. I put on a B&M cooler and it helped a little, but I need more. I'm going to go with your setup, the DeWitts radiator with EOC and TOC. Hope I have better luck. I hope to have the radiator next week, my next track event is the 22nd.

Has anyone used the larger transmission pan and the differential cover with fins? Does it help? Who makes a good set for the C5?

The differential coolers that I've seen are very expensive, anyone have a less expensive solution? Any room for just a fan?

I do HPDE's, and my next track day will include a day where I can go for as long as either me or the Vette can go so I'm looking for anything I can do after I install the radiator.

Dirty Howie

If I could get mine to stay down 210-220 I would be satisfied. I think if you did 20-30 minute sessions in the heat you would see the same temps I am. I do a cool down lap and some laps around the parking lot. The oil and coolant drop significantly but the tranny is still at 215

I was going to get one with the fan but after calling B&M they thought it would not help and possibly detract from airflow if mounted up front in the air stream


DH

Dirty Howie

Good luck with the new setup ...... It is great in heat and on street.

I'm just not sure that it helps when coolant is higher on the track....so I will try bypassing the radiator.

I am definately doing the bigger pan ..... thats a no brainer....don't know how much....but it has to help some having three more quarts to heat up.


DH

zeusoftexas

What gears are you running. One thing is, I have the 2.73's still in it, I can run around the 2.9 mile track with only one shift into 3rd down the straight. If you are running 3.45's you may be shifting all the time, that really causes the heat to build up. The 2.73's don't hurt me at all ask a couple of Z06's. 3.45 is better forthe drag strip I think? Myself and another vette both run a4's in autocross and both have 2.73. stick it in first and run the whole course. I suck really bad, but he finishs in the top 5 overall most of the time.

just a thought?

XPC5R

One trick often used in the tow vehicle (diesel) truck circles are manual torque converter lockup switches. Locking the converter normally dramatically reduces the heat produced.

If you are running most of the course in just 3rd or 4th gear, a lockup circuit may be useful.

MattB

I'm running 3.15, the 'perf' option.

Anyone know where to get a bigger trans pan?

How about the manual lockup? That sounds like it would be hard to manage though...

Dirty Howie

Sure..you are right....but I'm not going to give up my 3.42 gears.


DH