1fstGM

iTrader: (13)

I heard it is better to bypass the tranny oil running through the radiator if you have a tranny cooler. The guy told me it would be better if I just ran the oil through the cooler and then back to the tranny. Yes or No?

Blue2002SS

iTrader: (13)

no, run it though the factory one and then run it though the aftermarket one and then into the transimission.

1fstGM

iTrader: (13)

So this idea is not a good pne. Right now I do have it the way you are suggesting. I was just wondering if this would be better?

XFiveLiter

I previously used a 19k B&M that was routed through the radiator. The trans would run pretty hot in stop and got driving, sometimes over 200 .

I now have a B&M race cooler, it is rated at 29k BTU. I don't know how the BTU rating compares w/the GVW rating but it is twice the size and thickness of my old cooler.

I bypassed the radiator this time and it hasn't gone over 160 on the street. It hit 180 at the track after 3 back to back passes and cooled down quickly after.

It does take a while to heat up on the street, about a half hour of driving to reach 150. Can the trans run too cool?

1fstGM

iTrader: (13)

So this means bypassing the radiator is better? The explanation I got for it being better was that the radiator tries to cool down the tranny fluid with the water that is in it, and most of the time this water is very hot.

XFiveLiter

Yes, my engine runs hotter that my trans now. If I went through the radatior it would actually heat the trans fluid.

1fstGM

iTrader: (13)

Ok. I am gonna try bypassing the radiator this time.

Zo6Killer

Think about it this way: If you try to cool off the trans. fluid with 160-210deg. engine coolant, what happens? If you cool it off with 75-95deg. ambient air, then what happens? Correct on both counts. I say ditch the radiator and go straight to air-cooling.

Spydum

fyi, I think the idea is, you want your transmission fluid to be in normal operating range sooner, so running it through the factory cooler will actually bring it to that temperature faster, but having the 2nd cooler right after the output of the factory one will cool it back down to reasonable levels. Depends on where you live I suppose, but in most cases, I'd think you'd still want it to run through both.

1fstGM

iTrader: (13)

Will it do harm if it runs too cool?

ArmyVette

This hasn't been mentioned in the above posts.

The B&M series coolers have a vicosity (thermal) bypass value. As the oil warms, the value opens and oil passes through this supplemental cooler. The warmer the oil, the more oil that goes through the cooler.

The higher the GVW rating on the tranny cooler, the larger the cooler is so that it'll accommodate more oil and generate more cooling. This cooled oil is then recirculated to the transmission.

I'm not sure whether the factory installed (stock) tranny cooler works under this principle (thermal bypass) or not but I do know that B&M does.

Hope this helps.

Ed Blown Vert

iTrader: (2)

I am also debating on bypassing the stock cooler. Since I installed my Supercharger, engine temps have been higher. Which in turn increases the temp in the tranny.

Evil 99

The truth of the matter is that a stock system (thru the radiator) is a heat exchanger type of system. works well with stock components and NORMAL driving habits. We all know none of us are doing this so the largest external coolers are far more superior than any stock system. Temperature is the worst enemy to your transmission. Using high stall converters, hard acceleration, stop and go driving are all considered severe driving conditions and an external cooler is a must as well as trans servicing every 12,000 to 15,000 mile intervals. the other situation that is avoided by bypassing the factory cooler is that you eliminate any poss. of coolant contamination into the trans that can completely destroy your transmission.

F1_SS

Im wondering this also, im trying to design something that will keep the temps very low.