Transmission cooler install question

[Hooked on Speed]

When installing a cooler, do y'all bypass the radiator completely?

[STL_G8GT]

I did not... it went out from trans to radiator to cooler into trans.

[LDM]

Normally an auxiliary cooler is run in series, after the cooler in the radiator. The return line from the radiator becomes the inlet to the aux cooler, and the the return from that goes back to the transmission.

[Darkmanx]

I did not... it went out from trans to radiator to cooler into trans.

Shouldnt it be trans , cooler,radiator , trans?

[LDM]

Shouldnt it be trans , cooler,radiator , trans?

The radiator will be hotter than the cooler, so no, otherwise you'd probably be heating the fluid back up a little bit before returning it to the transmission.

[Hooked on Speed]

I figured if you bypass the radiator, the trans fluid would stay cooler.

[matts88yj]

Shouldnt it be trans , cooler,radiator , trans?


The radiator will be hotter than the cooler, so no, otherwise you'd probably be heating the fluid back up a little bit before returning it to the transmission.

I know my built trans and drivetrain setup isn't in a G8 but it's rather in my Jeep. Built 5.3 and 4L60E. After many discussions between guys just driving on the street to rock racers who beat the snow out of their rigs as well as a few trans builders I plumbed it up the way that Darkmanx stated. A few things I picked up on is that auto transmission like a stable operating temperature and not big fluctuations between them being cold, then hot, then cold again. With the way described above the small cooler that is in my radiator helps normalize the temp before being dumped back into the transmission. I have a Derale cooler in front of the rad all plumbed with -08 AN fittings and lines. That cooler takes the main batch of heat out of the fluid before it passes through the rad and then back into the trans. Now before everyone jumps on me saying that the fluid is going to jump to the temp of the coolant, it doesn't sit in there long enough for it to get to that temp. I have the main temperature probe for the gauge in the pressure port (again I know this isn't a 6L80) since after a few discussions this is a good place for the general working temperature of the trans. When I first did a temp setup on the outlet and inlet of the trans ports to see the temp differences each and every time coming back into the trans it was less than my coolant temp.

I'm not saying one is the definite over the other but that either way, with the proper plumbing, line routing and cooler size can achieve a cooler running trans. In traffic on the 85 degree day we had last week mine got up to 180 and that was after stopping and going for at least 5 miles. As soon as I got airflow, it was back down to 160 and stayed there the rest of the trip.

Just thought I would add a different view onto things.

[laserred]

I'd get the biggest cooler you can find and eliminate the radiator from the loop. Any time you run heat eliminators in series you lose efficiency. It's simple math, even 98% x 98%< 98% by itself.

[Darkmanx]

The radiator will be hotter than the cooler, so no, otherwise you'd probably be heating the fluid back up a little bit before returning it to the transmission.

Sound like you need a 160 t stat

[matts88yj]

I'd get the biggest cooler you can find and eliminate the radiator from the loop. Any time you run heat eliminators in series you lose efficiency. It's simple math, even 98% x 98%< 98% by itself.

I see the OP is from Houston so the temps are usually pretty warm (at least for most of the year) but one thing I will warn you about it too cold of a trans fluid is almost as bad as the fluid being too hot. For colder climates (if you drive your vehicle in them) I would still keep it plumbed through the rad in some capacity.

[LDM]

I was basing what I said on the factory GXP setup, which is the route I'm planning on eventually. If I'm wrong and the fluid in a GXP in fact goes to the aux cooler before the one in the radiator then I'll take back what I said. I don't have a GXP to check but I'm pretty sure it's how it's setup. Like Matt mentioned, too cold isn't good for the trans either. As a daily driver here in New England, where we have winter, I'll keep my radiator in the circuit. It'll help the transmission get up to operating temp quicker when it's cold.

[KRUG]

Ultimately a thermostatically controlled trans cooler is what is needed. With cold air temps a large cooler is not good for the transmission. Many OEM's are starting to use bypassing thermostats in there trans coolers now days. Ford and Chrysler are doing it on some vehicles.

[thebeast]

I just ordered he cooler from pcmforless. Shipped today already and will give impressions once installed

[todds87ss]

I have the PCM for less setup also...jut waiting for the install time. Being in the Houston area also, I am going trans, radiator (which, contrary to a previous post will reduce trans temps), cooler (at driver's side of rad), then back. I will agree that the single cooler would be more efficient, but I'm after the temperature reduction, not max efficiency. this is the method most used with this relatively small aux cooler.

[LDM]

(which, contrary to a previous post will reduce trans temps) If you were referring to my post, I agree with you, and perhaps just worded my post poorly. If you weren't referring to my post, then I still agree with you.
:cheers:
While a large, aftermarket cooler on it's own could possibly cool the trans fluid more than a small aux cooler in series with the radiator cooler, the radiator cooler on it's own definitely lowers the trans temps which is why all our cars have it. Add an auxiliary cooler in series after the radiator cooler and it will definitely lower the trans temps more than just the radiator cooler does, which is why the GXPs are set up this way.

[carey]

man with these contradicting arguments I will have no clue how I will run mine when I purchase it...

[matts88yj]

Ultimately a thermostatically controlled trans cooler is what is needed. With cold air temps a large cooler is not good for the transmission. Many OEM's are starting to use bypassing thermostats in there trans coolers now days. Ford and Chrysler are doing it on some vehicles.

This would be the most ideal solution.

Also I didn't mean to confuse anyone with my post earlier. Both will help cool the transmission fluid down for sure. I just went with what I understood from the trans builders and people who beat the snot out of their rigs. This exact debate went on for a few months on the offroad forum I'm on and it basically came down to that both ways of plumbing will cool the fluid, and there is no exact right or wrong.

[gman08]

You can always get a cooler with the LPD feature so that when it is cold the fluid wont pass through all of the cooler only the top two fluid channels. I know B&M and trucool have them on most of there coolers. I just bought # LPD4544 Plate & Fin type 30 plates, 22,000 GVW 9 1/2 x 11 x 3/4 and a 10in fan to put on top of it.

[Semperfire]

I just ordered he cooler from pcmforless. Shipped today already and will give impressions once installed

Is the PCM trans cooler a good part to get or should I go with a different set up? Seems like there are a decent amount of guys running these and other setups?

[Fatdaddy]

I have the pcmformless tranny cooler. My average tranny temps dropped 20 degrees. From 208 - 212 to 188 - 190, which was what I was looking for. I have a stock transmission. The cooler is very small. A larger cooler will get you a larger temperature drop. It is plumbed inline, tranny-radiator-cooler-tranny. You should get what will work best for your situation. The PCM kit is a convenient all in one package.




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[Semperfire]

The all in one is what I like about it but not sure its good for stall applications?

[1gr8ate]

Man y'all's trannys run hot I don't live far from Houston actually around there a lot even on track nights making 8 or more passes under a hour and a half or very sported driving conditions mine rarely sees 180 with no trans cooler I've never seen 200!

[thebeast]

Is the PCM trans cooler a good part to get or should I go with a different set up? Seems like there are a decent amount of guys running these and other setups?

I just removed it and went with an earls cooler.

It will not be enough for a stalled auto. I still hit 200 ith it on and cruised around in the 180's

[Semperfire]

Are the earls any harder to set up? The pcm one had the kit thats why it caught my eye but if it wont work then I guess I have to pice together a set up?

[Fatdaddy]

Man y'all's trannys run hot I don't live far from Houston actually around there a lot even on track nights making 8 or more passes under a hour and a half or very sported driving conditions mine rarely sees 180 with no trans cooler I've never seen 200!

I'm in Houston. The temps I quoted are highs, stop and go bumper to bumper traffic on the fwy during the summer with the a/c blowing ice cubes. Cruising I see temps in the 150 to 160 range. It was 89 today on my way home. Tranny was 152 degrees. Cruising temps before the cooler were 180 to 200. Regardless of how you measure it, I saw a 20 degree trans temp drop with the PCM cooler, which is exactly what I was looking for on my stock tranny.


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[todds87ss]

For those looking for a larger cooler with plug and play of the PCMFORLESS kit, you can get a derale cooler ordered with -6 ends, then order the PCMforLEss install kit. You still get plug and play, but you can choose which cooler you think is best.

[wreckwriter]

For street driven cars its generally not recommended to completely bypass the in-radiator cooler. Also, keep in mind that for best performance transmissions, like engines, need to be warm. I would not ever push a street G8 hard unless trans temp was at least 130.

[Semperfire]

Is there anyone else who has a kit that will work with stall applications? It seems like a simple set up but having no experience with them I'd like to keep it as basic as possible since I have no idea what else to order if I pieced it together.

[wreckwriter]

Is there anyone else who has a kit that will work with stall applications? It seems like a simple set up but having no experience with them I'd like to keep it as basic as possible since I have no idea what else to order if I pieced it together.

They all work with converters. Assuming you're not going with a stupid high stall, any of these are fine.

[Semperfire]

Thanks Wreck I found a thread with parts for a bigger one than the PCM I will try and piece together. Whats a stupid high number for a stall out of curiosity over 4k Im assuming? Are the install's on these pretty straight forward

[Erik@Lashway]

100% yes...bypass that crap.

[todds87ss]

100% yes...bypass that crap.

hmmm...:huh:

[thebeast]

Bypass radiator for sure. Just heats up the fluid .

[EcoBrick Bob]

My installer added a T/C when he added my Circle D. I have found that my tranny needs some heat to shift properly, and won't go into lockup mode until it is warm. So... how you route it would depend on whether your car will be in freezing or sub-zero conditions for much of the winter, in my opinion. Thinking I need the Camaro pan, as I did see 100+ Centigrade temps after several back to back 1/4 mile runs. That be said, my best run was the last, though drivetrain did smell hot when I parked. Left car idling, which is what I was told is best way to cool it down.

[Ewing]

True....I wouldn't want the radiator bypassed either in a winter state. In Florida however, bypass all the way. Mine is bypassed.