I am still looking for solutions to get the trans temps down on my heavily modded A6 2012 GS. Car has B&M trans cooler, DeWitt's radiator, Dual Spal Fans, Engine Ice coolant, oil cooler. Coolant temp tops out at about 200 but the trans temp creeps up to 210. I would expect that with the trans fluid plumbed through the radiator (not bypassed) the trans temp would not be higher than the coolant temp. Trans is a Century built A6 with a ProTorque 2600 converter. Wondering if anyone has tried wrapping the exhaust pipes with asbestos webbing where the pipes pass the trans and if that had any effect on the trans temp. Any other ideas will be appreciated.

BIGMAC

 

Just bypass the radiator, and run the trans cooler as a stand alone. My temps never get above 180 even in drag racing and I have a stall higher than yours.

 

Are these track temps or just driving around town? If track temps, I wouldn't really worry about them as 210 isnt anything to be concerned about there.

Are you running a 160* engine coolant thermostat? If not, that would really bring the temp of the whole system down.

I'm from south LA, and it's about as hot and humid here as you'll find in the US. I have my B&M cooler plumbed in series with my radiator, with a temperature switched fan. I used to run the cooler standalone, and it would take too long to heat up and once it did it would skyrocket to 200+ on the street just driving around. Now that everything is plumbed "correctly", it takes active effort from me to get it over 185 on a 100+ degree day. Typical temps are 165. No oil cooler.

If you're like me, your B&M is installed in your front driver fender. If so, make sure that you're flowing enough air through it. The people who installed mine had a number of 1/2" holes drilled through the wheel well for this purpose, which I wasn't satisfied with. I essentially cut out the entire section of wheel well behind the fan and added some steel grate material which I spray painted black to protect from rust. I also added some ducting from the brake cooling duct hole in the front of the fender to directly blast cool air on the cooler and also to give a low-resistance path for the fan to pull from. If you haven't done this yet, I'd expect a significant drop in temps just from the increased airflow.

Now, I'm running a stock stall right now, but I feel with a stock radiator in an incredibly warm climate with aggressive daily driving my temps are still exceptional. My dad's C7A6 runs over 210 daily and he drives the thing in eco mode, just for some extra background.

Short of all that, if you're running the same B&M cooler that I am, there are much better bar-and-plate style coolers out there from manufacturers like Setrab. If I find heat to be an issue after I add a 2800 stall and cam later this year, I will be upgrading to one of those and use the fan from the B&M.

 

Thanks for the detailed response. The 210 on the trans was in street driving in 92 degree ambient. The car is just back from the builder and has not been to the track yet. It is primarily a drag car. My builder mentioned possibly drilling some ventilation holes in the fender well (trans cooler is in front of the left fender well) and I will try that. I find your comments on bypassing the radiator interesting as like many opinions on the Corvette Forum there is about a 50/50 split on bypass/no bypass . I will ask my builder about alternative trans coolers but he already assured me I have the best one that will fit a C6 with an ECS kit stuffed under the front. I will keep plugging until a solution is found.

BIGMAC

 

B&M cooler with fan.... vent in wheel well to let air pass through.... bypassed radiator... trans lines run away from headers....

Built trans, stall... stays very cool under all conditions... never see over 180.

 

On road courses, I couldn't keep my trans temps under 250* with the B&M cooler and fan mounted in the wheel well with a vent. I took out one of the fog lights and put it in there and still had temps above 235*. Taking it out of the rad made things worse for me but I too have read it helped others.

I will say that I would not have done a thing @ 210* but you do need to see where it is on track. My final solution was to get the biggest Setrab that would fit in the fog light space. I got 2 in fact. Now, at 60* - 65* ambient, I max out @ 210*. At 85* - 90*, max is 230*.

My 2c. Ditch the B&M. The Setrab stacked plate design is far superior. When you do and put the 2 coolers next to each other, you will see, night and day.

 

The way I see it, the factory cooler in the radiator is there to regulate the temperature of the transmission fluid. This really helps when you're trying to get the transmission to the 140-160* it needs to be at before it will shift well under load. Now, obviously, 200* water isn't going to cool anything to below 200*, but consider how much greater the heat transfer capacity of water is than air. The radiator should, under most circumstances, lower your trans temps to right around your ECT. The higher the heat output of the transmission, the higher the post-rad temps are going to be. With proper airflow, the B&M should get you around 20* of cooling.

Obviously, if you have the room and the money, you can make a better thermostatically controlled standalone air cooler for your transmission than the radiator. Given the constraints of the vehicle, however, I think that's pretty difficult to do. Others have certainly had different experiences, I'm simply sharing mine: my car works better with the factory cooler included in the loop.

I would focus on getting as much airflow through the cooler as you possibly can. This is a nearly free solution.

If you have what I have, your cooler has a Spal puller fan on it, make sure that it's set up to pull air through the cooler i.e. the fan should be on the rear of the cooler. Also, make sure the fan is either running all the time, or controlled by a temperature sensor that will turn it on when the trans temps reach a certain level. Mine turns on around 160 per my settings.

So you still have the brake cooling ducts intact? if so, that's a big source of cool, high pressure intake airflow that I have and you don't.

Maybe you could snap a few pics of the cooler setup?

 

LG Motorsports Differential & Transmission Cooler Fabricator Kit

 

I have a NA LS2 with a 2800 stall and B&M trans cooler by passed the radiator and it runs below 200 in 90 degree heat


Have you looked at the specs of your converter. STR of higher than stock converters is 1.8 to 2.7. You should have a low STR converter as you have a supercharger. This is so that you do not blow through the converter. The wrong STR could cause excessive heat from slippage

 

Pull the clips and bypass the rad, im sure you can get a temp regulated check valve and run in conjunction with the rad and then it bypasses on temp setting

 

How are the Setrab coolers different from the B&M? The B&M I had on our C5 was also stacked plate and seemed well made, kept the A4 temps down even on a road course when plumbed in series with the factory radiator cooler.

 

The B&M that is most popular is a traditional tube and fin type cooler with a fan, which is not as effective a cooler as a bar-and-plate. I imagine that the B&M and Setrab stacked plate coolers are similar in effectiveness, and either would be an improvement over the kind of cooler I run.

 

There's a whole lot more to coolers than just the brand. I have a B&M 70273 that's 11 x 5.75 x 1.5 stacked plate and rated at 15,000 BTU/HR. Because of how it's mounted, I can only get airflow through 11 x 3, which means I'm getting about 8,500 BTU/HR effective usage. Rather than cut up part of the car and then create a new mount, I just bought a Derale 51006 that's 12.5 x 2.875 x 2 stacked plate and rated at 20,000 BTU/HR. Now I'll be able to get full airflow through my 3" opening and the 2" thickness of the plates is why there's an extra 35% more capacity.
I still need to check on exactly how the Derale t-stat functions before I order, since their description is a little vague, but I do plan on using one.

If this doesn't do the job, I'll buy a second one and mount them in series.

 

It's not rocket science. Myself and a few others have said what's working perfectly. Why not just do the same, rather than reinvent the wheel.
If my built trans, with triple disc converter, behind 1000 rwhp, stay cool, I am pretty sure a similar cooler setup would work for almost anyone.
The exception might be road racing, which I dont do. That is probably hardest on the trans and I would think maybe dual coolers could be a consideration for that.

 

Picture attached. Cooler is mounted horizontally in front of the left front fender well.

 

that will never get the lower temps your looking for

 

Please keep us posted on that!

 

A not so good picture of mine installed. the brake duct flows right onto it, and a vent installed on the inner fender lets the air flow freely through it.... it just works.

 

Maybe that works in cooler Canada and most parts of the USA, but with a 4000 stall in heavy rush hour stoplight traffic in Phoenix during the 100+ days each year that exceed 100 degrees, it doesn't work for me, since I fall in to the "almost anyone" category. It also doesn't work going up steep mountain grades where the ambient air is only slightly less hot at the top.

I've had two different coolers, fans and no fans, and several different mounting locations. When the 15K BTU and OEM radiator didn't work in one location any different than when in another with half the cooler capacity blocked, it told me that the new location was good, but the capacity was the limiting factor. After fighting this with different methods for years, I've determined that going for overkill on the cooling and then with a t-stat to limit the downside during the winter, is the only solution. With only 5 more days of 100 degree temps expected this year, I won't have a result to post until next September.

 

Granted.. we don't get 100+ here.. I will give you that. I guess there are exceptions. We do occasionally get 90ish and very humid, and I have had no issues in those conditions.