I need advise for a choice in trans/oil cooling

[Schmieder]

1996 Grand Prix SE 3100v6 with T04E .50 trim turbo at 6-8 psig

I have two B&M Coolers. One is dedicated to trans at 9.5k BTU. The other is optional for oil or trans cooling at 14.4k BTU. The reason I dedicate the 9.5k to trans is the bypass feature for fluid that is cold.

I could use the other to add the trans cooling to 24k BTU or use it to cool the oil before the turbo.

My consideration is this. The transmission is the weak point in the turbo set up. Knowing 95% of all trans failures are heat related, I need a strong cooling. And the oil system won't see too much more heat and I'm using high quality synthetic oil. So I am leaning towards 24k BTU cooling for the trans. But I would like a little advise, please.

Should I cool the trans at 24k BTU?

OR

Cool Oil at 14.4k BTU and leave trans at 9.5k BTU?

[robertisaar]

cool cooler () i've never heard of one with a temperature bypass built in...

is the tranny cooler built into the radiator being used? if not, you could pipe the oil through there, it would stay roughly within the same temp as the coolant. which could be a good thing depending on your thermostat.

[Schmieder]

cool cooler () i've never heard of one with a temperature bypass built in...

is the tranny cooler built into the radiator being used? if not, you could pipe the oil through there, it would stay roughly within the same temp as the coolant. which could be a good thing depending on your thermostat.

That is an interesting idea. Though, how much of a thermal effect would the hot motor oil have on the coolant?

As of right now the trans fluid is piped to the rad cooler then the 9.5k cooler.

Now, using the rad cooler to moderate the motor oil is a very interesting idea as you said it would help keep the motor oil around 190-200 degrees. That would be beneficial using synthetic oil as it is thinner then normal oil in the same weight range 5w30. The slightly lower temp would bring synthetic oil to a similar viscosity as regular motor oil, in theory that is.

Here is the cooler w/ bypass feature.

link

The coolers assembled with hose barb ends include a unique bypass feature allowing a controlled amount of ATF to bypass the stacked plate core when the fluid is cold. This is beneficial in cold climate areas to guard against lube system failure. Controlled by viscosity, fluid is returned directly to the lube circuit through bypass openings in the stacked plate core. As the temperature increases, more ATF is directed through the core. This highly efficient design combines improved protection against lube system failure with the required levels of optimal heat transfer.


I have to run out but I will be back to discuss the oil to radiator cooler further.

Thanks

[robertisaar]

That is an interesting idea. Though, how much of a thermal effect would the hot motor oil have on the coolant?

it will heat it up obviously, but it's much easier to remove heat from the coolant than it is removing heat from oil... and the heat that doesn't transfer will be stuck in the metal until airflow removes it.

[pocket-rocket]

As of right now the trans fluid is piped to the rad cooler then the 9.5k cooler.

I've always been under the impression that you want your trans fluid at a specific temperature, so when plumbing in a trans cooler you would want to go trans > trans cooler > radiator trans cooler > trans. That way your fluid doesn't drop out of it's optimal temperature thanks to the coolant.

[robertisaar]

I've always been under the impression that you want your trans fluid at a specific temperature, so when plumbing in a trans cooler you would want to go trans > trans cooler > radiator trans cooler > trans. That way your fluid doesn't drop out of it's optimal temperature thanks to the coolant.

tranny fluid does like a certain temp, roughly 180*F. not sure if synthetic tranny fluids run on the same scale though.

EDIT: but the thermostatic valve should help keep it at the correct temp...

[Schmieder]

it will heat it up obviously, but it's much easier to remove heat from the coolant than it is removing heat from oil... and the heat that doesn't transfer will be stuck in the metal until airflow removes it.

"It will heat up obviously"...lol

I was more along the lines of thinking about effects of hotter coolant entering the engine block. Such as, will cylinder #5 get too hot since that is the last cylinder to be cooled kind of questioning. But I suppose the thermostat will open sooner and the temps will remain as thermostat dictates.

Pocket-Rocket makes a good point about the coolant lines keeping trans fluid temps stable. Not sure of how important the function is, but something for us to ponder over.

Placing the trans fluid path to the rad chamber last isn't a bad idea either. Even if the external coolers drop trans temp below desired operating temps, the trans fluid would help to cool the rad coolant.

Here is my new plan

Ok, I'm going to route the trans fluid to the first cooler, 14.4k BTU that doesn't have the cold bypass option. Then to the radiator cooler. The last step is the 9.8k BTU cooler with cold bypass.

hot ATF > 14.4k BTU > Rad Cooler > 9.8k BTU w/ bypass > TRANS

So the ATF will always need a cooling when hitting the 14.4k BTU cooler. The ATF will be balanced by the rad cooler and if the ATF is still too hot, the 9.8k BTU cooler will kick in. If the ATF is cool enough after the rad cooler, the 9.8k BTU cooler will bypass.

[bszopi]

3 coolers for the trans is overkill.

[robertisaar]

3 coolers for the trans is overkill.

blown 660s in a mustang is overkill.

but we're not complaining...

[Weatheralls Auto]

I have dealt with Trans Temps by using a 5 Speed lol.


I'd love to see more pics of the install, remember to try and keep it all clean and organized.
IMHO a too "busy" engine bay is not desirable.

[Schmieder]

I have dealt with Trans Temps by using a 5 Speed lol.


I'd love to see more pics of the install, remember to try and keep it all clean and organized.
IMHO a too "busy" engine bay is not desirable.

I want a 5-speed but can't afford it just yet.

One thing the auto trans has over manual is the auto will ALWAYS shift faster and more precise then any person with a manual could.

I'll get some pics up some day soon. In fact, today I bought some batteries so I can snap a number of them tomorrow.

The trans coolers are ahead of the radiator, out of the engine bay. My install is very similar to many turbo installs I seen on the internet. I used those pics as a basic starting guide to my build.

Just like a dream girl, it is tight in there, but not too tight as to be sucking a watermelon through a garden hose, lol.

3 coolers for the trans is overkill.

You are absolutely correct.

However, as long as the radiator keeps the ATF at 180-200, all is well.If the coolers bring the ATF below coolant temp, the ATF will help cool the coolant, lol.

Well, if 95% of tranny failures are from heat, I won't have much to worry about there.

[pocket-rocket]

Well, if 95% of tranny failures are from heat, I won't have much to worry about there.

I had a cooler meant for a 14k or 25k gross weight truck on mine and still blew it up. Then again, I also added Lucas to it too. I'm not saying Lucas is the root of my problem, but heat shouldn't have been a worry with mine. You can't absolutely prevent wear in a wear and tear piece of hardware.

[Weatheralls Auto]

95% of 50% statistics are are made up, 5% do not exists.
Of the other 50%, 15% are lies and 35% are based of some factual event.

LOL

[Schmieder]

All very good points posted here.

Maybe I should just use the 14.4k BTU for the transmission before the radiator cooler and use the 9.8k BTU cooler for the oil feed just before the turbo.

Yeah, the trans can be killed with brute wear and tear. But ask many techs who work on auto transmissions, I'm sure many hear do. A LOT of auto trans that are destroyed are killed by excessive heat.

I'm going to run about 6-8 psig boost. Heat is a larger concern in my application then torque wear and tear. As long as I don't exceed the torque from a stand still WOT the brute wear should be low as the trans sees the greatest torqing load at stand still WOT acceleration. At 6-8 psig, I am far from reaching that limit. By the time the turbo spools up the velocity of travel will be great enough to negate any additional torque and keep it below 280 lbs/ft.




About how much more heat will be introduced into the motor oil from the turbo when it's spooled up?

[pocket-rocket]

All very good points posted here.

Maybe I should just use the 14.4k BTU for the transmission before the radiator cooler and use the 9.8k BTU cooler for the oil feed just before the turbo.

That's probably how I would hook things up if it were me. Then again, I see others that run a turbo that don't even do a pre-turbo oil cooler and they seem to be just fine. I'm sure with mine (and being a DOHC) mine was brute force wear and tear from dead stops with hard accel. and exceeding the 4T60-E's max RPM. I kept the trans cooler to eventually adapt it as an oil cooler