mark b

I have an C5 auto with a 3200 stall converter and B/M tranny cooler, I track it, been having high temps go on, around 260 (I then pit) Thinking of a dewitts type radiator with eoc and tranny cooler, but if I get just a diff cooler(DRM or others) would that solve the problem of high tranny temps? On the street I have no problems with tranny temps the B/M cooler works great and tranny temps stay around 185, even driving hard and fast. The oil goes up to around 235 to 245 so this cooler is not needed for anything but tracking the car. Some suggestions before I spend money? I want to head to the Glen 7/15 and 16 with PDA but I have to take care of this and spend some money. I just want to make the right decision, thanks.

help me out guys!

AU N EGL

not in series, different fluids

One on each, the trans and diff YES

Rob Burgoon

Someone expressed an opinion around here that the tranny got a significant amount of heat from sitting up against the diff. If you buy into that, there might be some benefit to the tranny by installing a diff cooler.

I have a tough time believing that the tranny can't make itself nice and hot though.

<edit> Oh. You have an auto. Yep. It's gonna get hot. For track use I would be looking for some serious cooling for the tranny. <\edit>

J.R.

Agree with above.

On an MN6 you can probably get by with wrapped exhaust pipes and a diff cooler but with auto you will definitely need two coolers.

Expensive, but a trans and diff plus labor is a whole lot more expensive.

mark b

so u guys are saying that the radiator with the engine cooler and tranny cooler is no good, but individual coolers on the tranny and diff is better?

73-84 IMSA Widebody

With coolers, bigger is better, if you have room.
Summit Racing has 20x10x3/4 coolers for $50. Plumming them in line before the radiator is straight forward and you can leave your tranny/radiator cooler connected for "double cooling".
If the diff cooler is a new add on it may need a pump but I am not familiar with how the "newer" cars are set up.

yakisoba

In the C5, you need a pump for either diff or tranny cooler. LG's diff cooler setup gets around that by using the diff AS the pump (requires a bit of fiddling and welding), but for the tranny, still need a pump to move the fluid around.

Bill Dearborn

You probably need to get a bigger cooler for the tranny. Not sure which B&M you have but you should be using a large plate cooler at a minimum (the largest B&M Supercooler). Running a larger radiator with a built in tranny cooler plus the external cooler will help also. I would also wrap the exhaust pipes where they pass the tranny.

Bill

MattB

Hate to tell you, I did all that and the trany temps still went through the roof: big rad with cooler, external 11x11 plate cooler, Syn ATF, built A4, low stall converter, still over heated. Do some searches here, there are a couple of guys who claim they solved the issue. Me, I'm going to give a M6 a try, although that means relearning how to drive LOL.

Rob Burgoon

I was afraid of that.

yakisoba

Yeah, it seems it's quite hard to run an A4 under road course conditions.

Rob Burgoon

Quite hard to ride in one too. Weekend before last my student had a C6 with an A4. That 2-3 shift packs quite a wallop!

mark b

Thanks guys for the feedback...this is obviously an issue with these cars. I think Im going to try the dewitts radiator first and see if my B/M tranny cooler will fit with the new radiator. Im hoping it will so Ill have additional cooling. If that doesnt work then Ill look at getting a separate cooler in additon to my B/M cooler/stock radiator.. Im going to check to see if B/M has made a more efficient cooler for race applications.. If the new dewitt radiator works, then Ill get a diff cooler and I should be fine for the 30 or so minutes on the track each time. induro races are out though. My final question is Has anyone here on this forum used the dewitt radiator and a separate tranny cooler(against the radiator) and it fit? I dont want to buy this radiator if my existing trannycooler doesnt fit. (I dont think it can be mounted anywhere else) If it doesnt fit then the individual coolers are a go

RAFTeRACER

You may want to bypass the radiator cooler entirely and only run the external cooler. Your engine can handle higher temps than your transmission. If your engine hits 260 on the track its no big deal but thats a little warm for your tranny. No sense in preheating your fluid in the radiator.

73-84 IMSA Widebody

I was under the understanding that auto trannies typically run hotter than engines, not suggesting this is a good thing. My only real experience is with our tow vehicles as we run an M-21 in the car.

For anyone with gauges on an auto tranny what are you seeing, I can always use a little education