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Transmission Cooler 727

Posted By: SILVER67

Transmission Cooler 727 - 03/10/10 02:23 AM

Hey Guys,

Do any of you run an external tranny cooler on your car and then bypass the cooler in the radiator? I have a '67 R/T with a mild 440. Would I be able to get away without the radiator cooler hooked up? The car is a street/strip car. I am planning on a installing a B&M 11" x 11"x 1-1/2" Supercooler. GVW 29200. Thanks Guys, Michael
Posted By: dOc !

Re: Transmission Cooler 727 - 03/10/10 02:29 AM

Almost 30,000 lbs GVW ? ..way WAY toooo big. uNless you are not worrying about "killing" some of the stall speed of the converter.

I know guys that run 10 and 9" converters ON THE STREET with the radiator ATF cooler/warmer only !
Posted By: 383man

Re: Transmission Cooler 727 - 03/10/10 05:19 AM

I installed an aluminum rad this year but I still use the same trans cooler that you can see some of in front of the rad. I only used the external cooler when using this stock rad also. I have not had any heat issue's with the trans and I drive it alot in the summer months and race it a few times a year also. Ron



Posted By: Azzkikrcuda

Re: Transmission Cooler 727 - 03/10/10 05:37 AM

The internal radiator trans cooler isn't much more then a tube running in one side and out the other. I bypass it when I put on an external cooler. Cleaner install and less hose/tubing to leak.
Posted By: rebel

Re: Transmission Cooler 727 - 03/10/10 07:31 AM

i have the same B&M supercooler but fitted a fan to it. i mounted mine at the rear of the car & have a temp guage on the return. they're a great cooler & are superior to the endless multipass units as they thave less restriction. do it!
Posted By: Quicktree

Re: Transmission Cooler 727 - 03/10/10 10:52 AM

Quote:

Almost 30,000 lbs GVW ? ..way WAY toooo big. uNless you are not worrying about "killing" some of the stall speed of the converter.

I know guys that run 10 and 9" converters ON THE STREET with the radiator ATF cooler/warmer only !


explain how it will effect the converter?
Posted By: Ron Silva

Re: Transmission Cooler 727 - 03/10/10 05:20 PM

Quote:

Quote:

Almost 30,000 lbs GVW ? ..way WAY toooo big. uNless you are not worrying about "killing" some of the stall speed of the converter.

I know guys that run 10 and 9" converters ON THE STREET with the radiator ATF cooler/warmer only !


explain how it will effect the converter?



I put a huge cooler on my Car. I want to go get tacos through the drive through when it is 105 deg outside and I do not want any issues. My Transmission guy said you cannot overcool the fluid in the trans. I specifically asked him about having this huge cooler and driving in the winter. He said not a problem.

Attached picture 5856283-19.JPG
Posted By: dOc !

Re: Transmission Cooler 727 - 03/10/10 05:35 PM

Quote:

Quote:

Quote:

Almost 30,000 lbs GVW ? ..way WAY toooo big. uNless you are not worrying about "killing" some of the stall speed of the converter.

I know guys that run 10 and 9" converters ON THE STREET with the radiator ATF cooler/warmer only !


explain how it will effect the converter?



I put a huge cooler on my Car. I want to go get tacos through the drive through when it is 105 deg outside and I do not want any issues. My Transmission guy said you cannot overcool the fluid in the trans. I specifically asked him about having this huge cooler and driving in the winter. He said not a problem.



TWO points here ...

How will it effect the converter? ..... not up-to-temp ATF will effect stall-speed. Talk to anyone who makes HP converters. And LOOK at how the OEM lockup converters and OD transmissions work ... they do not operate "properly" until the ATF is up-to-temp.

Your trans guy says ATF can not be toooo cool ? .. again - TALK to any converter manufacturer. Now if you are not worried about the stall speed ... it is BESTer to run a huge cooler on a typical HP 727.

THIS is what I plan on using on my motorhome ...which will be going down-the-road at as-much-as 20,000 lbs.

B U T - I will have the biggest FATTEST lowest stall-speed converter I can dig-up.
Posted By: Ron Silva

Re: Transmission Cooler 727 - 03/10/10 05:41 PM

I don't care if my stall speed varies a couple hundred RPM.

Plenty of Guys will start their car stone cold, do their burnout and them make a pass. No damage to transmission results.

I believe Modern cars delay the converter locking and gear shifting for EMISSIONS reasons.
Posted By: dusturbd340W5

Re: Transmission Cooler 727 - 03/10/10 07:27 PM

Quote:

I don't care if my stall speed varies a couple hundred RPM.

Plenty of Guys will start their car stone cold, do their burnout and them make a pass. No damage to transmission results.

I believe Modern cars delay the converter locking and gear shifting for EMISSIONS reasons.




we have a winner emissions is the only reason they delay the shifts.
Posted By: maximum entropy

Re: Transmission Cooler 727 - 03/10/10 08:00 PM

it is possible to overcool in cold weather, which would require an inline thermostat, if you're not running fluid through the cooler in the radiator (which you should be, trannies, like engines, have optimum operating temperatures).
Posted By: turbobitt

Re: Transmission Cooler 727 - 03/10/10 08:06 PM

I'm in the process of doing some transmission dyno testing on some brand X TH400 stuff. I don't think the trans fluid temp will vary the stall that much but will say that the bar and plate style coolers have significant flow restrictions. We seen very high converter charge flow pressures when adding a bar and plate style cooler. I would tend to think that this would decrease the stall since the oil is kept in the converter and keeping it full.
Allan G.
Posted By: Ron Silva

Re: Transmission Cooler 727 - 03/10/10 09:11 PM

Quote:

I'm in the process of doing some transmission dyno testing on some brand X TH400 stuff. I don't think the trans fluid temp will vary the stall that much but will say that the bar and plate style coolers have significant flow restrictions. We seen very high converter charge flow pressures when adding a bar and plate style cooler. I would tend to think that this would decrease the stall since the oil is kept in the converter and keeping it full.
Allan G.



Are you specifically talking about B&M coolers? Because that is what I have and it does not appear restrictive (looks can be decieving). But on the other hand I wiped out 3 thrust bearings before I had Dave Restrict orfice my converter charge circut (904). I have heard that they commonly do this with Chevies, hense your experience with a TH400.

Also NOTE: I am not saying it is good to have cold trans fluid. Certainly there are benifits to having the oil at a nice 150 degrees or whatever, but it is not going to harm anything on a race car to have cold oil or on a not often driven hot rod. Especially my car since I have aluminum Drum and am constantly changing the oil to purge the aluminum in the fluid.
Posted By: turbobitt

Re: Transmission Cooler 727 - 03/11/10 12:24 AM

Quote:

Quote:

I'm in the process of doing some transmission dyno testing on some brand X TH400 stuff. I don't think the trans fluid temp will vary the stall that much but will say that the bar and plate style coolers have significant flow restrictions. We seen very high converter charge flow pressures when adding a bar and plate style cooler. I would tend to think that this would decrease the stall since the oil is kept in the converter and keeping it full.
Allan G.



Are you specifically talking about B&M coolers? Because that is what I have and it does not appear restrictive (looks can be decieving). But on the other hand I wiped out 3 thrust bearings before I had Dave Restrict orfice my converter charge circut (904). I have heard that they commonly do this with Chevies, hense your experience with a TH400.

Also NOTE: I am not saying it is good to have cold trans fluid. Certainly there are benifits to having the oil at a nice 150 degrees or whatever, but it is not going to harm anything on a race car to have cold oil or on a not often driven hot rod. Especially my car since I have aluminum Drum and am constantly changing the oil to purge the aluminum in the fluid.


I want to say that my test cooler was an older B&M unit. In my test with the TH400, we restricted the converter charge feed orfice to .113" and was able to maintain over 100 psi cooler circuit pressure. With this style cooler, pressures went up to ~150 psi. I don't have the exact numbers since my notes are at the shop. We will be testing a tube and fin style cooler along with different stlye input shafts and converters.
I am interested in your 904 feed restriction. What line pressure are you running ? Did you measure the cooler pressure ?
Sorry if I hijacked this thread.
Allan G.
Posted By: Ron Silva

Re: Transmission Cooler 727 - 03/11/10 01:06 AM

I was told that Mopars do not pressurize the cooler much if at all. That the oil exits the converter working circut and then goes through the cooler and drains over some bearings,bushings etc right into the Pan. I would have never expected that much pressure in the trans cooler. I do not know what he did to restrict the charge circut. But the car drives the same with the same 60 foot.
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