mrvedit laying the smack down!
Op listen to mrvedit, 01ssreda4 & Jake
I read a lot of there tranny posts and have learned lots. With that being said I run my cooler inline with the stock cooler but will be switching to a setup like 01ssreda4 this spring

 

Here's my opinion,
On a hot rod, you are typically going to omit the factory cooler once you do anything that exceeds factory capacity. Stall converter being one.

Use an adequate (18,000 GVWR or larger, as big as mountable) cooler. Use either braided, teflon, or steel lines. Nothing wrong with steel lines as they transfer heat while the fluid is moving. i.e. they add cooling capacity.
Do not use clamp on hose except in an emergency and do not use push-lock.
ATF is very flammable when warm and headers WILL instantly cause it to flash combust. BTDT.
-6 hose or 5/16 line is ALL that is needed. -8 hose isn't doing any good.

IF you are using a vehicle for a daily driver in a cooler climate (Northern US, Canada, Alaska, etc,) the OEM rad cooler should be used and then go through the aux cooler.

Liquid to liquid coolers are more efficient (for a given set of circumstances) than a liquid to air.
The trans cooler portion of a radiator is typically on the "cold" side of the radiator. The water temp on the cold side is after cooling, so it won't be engine temp (185-230*), it is typically much less. So the ATF in the radiator is being cooled by a liquid to liquid cooler at less than engine temp.

In my experience a transmission (even stock with stock converter) makes heat quicker than the engine. Smaller volume of fluid, smaller cooling system, etc. If you watch trans temp vs. engine temp on a cold start, the trans can get to temp much quicker than the engine. Not necessarily on all vehicles but on most I have watched from cold start (Powerstroke trucks, 4th Gen F-bodies that I was doing trans tuning, etc).

Back to that "given set of circumstances".
When dealing with heat and cooling systems, engineers refer to the difference between the fluid temp and the ambient temp as "delta". Any cooler will have greater efficiency when there is a greater delta. If the ATF is 200* and the ambient temp is 80* the cooler will be more efficient than if the ambient temp is 100*.
The in radiator cooler is efficient and will drop the ATF down from the 200+ degrees after hot lapping the trans to the say 160* using the cold side water temp of guessing 120-130*. Then the auxiliary cooler can bring it down further to get it back in the pan at 100-120*. Pan temps will be higher and immediately bring the temp back up somewhat.

 

What is the optimal temp for a tranny? I know heat kills. I live in S. Florida and I just went from rad then cooler - to by-pass rad to a stacked plate. It is running 30* cooler...this is a 80% strip 20% street. What do the experts think...cooler is better right??

 

Cooler is better. 120*-180* is ideal IMO. Seeing 200-210 when beating on it is OK but is showing the cooler capacity is marginal.

 

Everyone can feel free to debate the finding if they'd like. We did the tests and produced the facts... Yes, I, as well as every other employee in the shop knew that the bottom line is the return on a 2004R...

As far a tube and fin VS> stacked plate. We've fixed many over temp issues by simply replacing a tube and fin cooler with a stacked plate design.

 

I daily my yukon, which has a trans temp gauge, my camaro has an aftermarket pan mounted one. Ive owned my yukon a year and the camaro almost 8. Not one time, in all that driving has either of these transmissions heated up at even half the speed on the coolant. Period.....no matter what the circumstances or cooling devices used.

 

Maybe you had a faulty cooler I dunno....but I think the rebuttals from some members speak for all of us, sorry

 

Yes, you are correct. We had many faulty coolers. Every one of the tube and fin coolers anybody has ever used has been "faulty"... Faulty by design.

 

Ive honestly never used one by choice, not one time. Im very well aware though that lots of trucks and suvs have them as aux coolers from the factory, my two suvs included.

 

One other thing I will add is that these initial tests were done right around 20 years ago. During the 20 years since then, I have had many many experiences with continuing to prove the results, by either changing cooler types, location, or routing. There is another local "performance shop" that is famous for bypassing the radiator when doing auxilliary cooler installs. My shop get's these cars in all the time with the trans temps too high. Simply rerouting the fluid back through the radiator first, fixes them. I say "simply", but this is an LS specialty shop so some of these cars are GTOs. The shop discards the original radiator lines, so we have to order new lines from Australia. They have a unique fitting called a "jiffy-tite" fitting. I'm not here to argue or debate. I'm simply posting what we've proven to be true in every instance.

Frank

 

When you replaced the tube and fin cooler with a stack plate, were both coolers of similar physical size?
Here is an article claiming the stacked plate is indeed most efficient:

http://www.etrailer.com/faq-about-en...n-coolers.aspx

I know in the BMW world that stacked plate engine oil coolers are considered better than the OEM tube and fin.

You mentioned the Tru-Cool 4490 cooler (stacked plate), but that has barb fittings which I would never use. Do you know of a similar performing one with threaded fittings?

 

Based on showvette's and Jake's comments (#23) it seems that a marginal external cooler may need the assistance of the stock/radiator cooler to properly cool the trans. Clearly if the trans is exhausting fluid at 300F then the efficient liquid-to-liquid cooler in the stock radiator should cool it to close to engine temp. Whether that is 220F or 180F is up for hypotheses, but either is clearly less than 300F. The external cooler then receives it at 220F/180F instead of 300F.
Of course if the trans is exhausting fluid at 180F then the stock cooler may actually heat it.
Based on dozens, if not hundreds of comments on this forum, it seems that an adequately large cooler, properly mounted, will cool the transmission by itself. This has the advantage of avoiding the possibility of a cracked stock cooler from destroying the trans. As the Gen-4 are getting to be 15+ years old, radiators are failing.

I'm certainly willing to try a stack plate cooler, although my trans temp barely hits 200F when running at the track with runs 10 minutes apart.

 

Actually, a stacked plate cooler of smaller size and GVW has proven to work better than a larger tube and fin style. Our tests included many various Hayden tube and fin coolers.

Yes, B&M makes several auxilliart coolers that will accept A/N fittings. The reason I specifically listed the Tru Cool is because we specialize in F-Bodies and that particular design fits well on them. Using the supplied rubber line that comes in the Tru Cool kit is acceptable because it's ATF compatible, but we understand people feeling more secure with braided. The Tru Cool is also a few dollars less than a comparable B&M. Eventhough I broke down the difference between tube and fin and stacked plate, it's also fair to mention that not all coolers of either design are created equal. Some stacked plate coolers have more plates. The more plates, the better they SEEM to cool. Hayden makes a stacked plate cooler that is the same dimensions as the Tru Cool 4490 but it has less plates. I haven't had the opportunity to do actual tests to get exact results to see how different they cool. I know the Hatden is right around $20 cheaper than the Tru Cool.

 

The B&M coolers are Tru-Cool, made by Long Industries, a division of Dana.

 

I'm running 150* now!!

 

Yes. All of them are stamped LONG. They're usually a little less expensive from Tru Cool. Very much the same as many auto parts. Many are made on the same assembly line and just put in different boxes. It's absurd to see the difference in price on some of those parts though...LOL

 

Cool. (All puns intended)
Any chance you can post the part number of stacked plate cooler with threaded fittings?

 

70274 is one.

 

Fittings were a pain the butt for me while trying to find compatible fittings for both my filter and extra cooler. There's A/N fittings, SAE, metric, etc etc

 

My current B&M tube/fin cooler came with threaded fittings - 1/8" pipe which are easy to adapt to AN. I've seen some stacked plate coolers come with AN fittings but they were ridiculously priced in the $350 range (for the Break My Wallet (BMW) world).