Notices
924/931/944/951/968 Forum Porsche 924, 924S, 931, 944, 944S, 944S2, 951, and 968 discussion, how-to guides, and technical help. (1976-1995)
Sponsored by:
Sponsored by:

Home made transmission cooler

Thread Tools
 
Search this Thread
 
Old 01-30-2012 | 12:53 AM
  #1  
Van's Avatar
Van
Thread Starter
Rennlist Member
 
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
Default Home made transmission cooler

I wanted to add a tranny cooler to my race car, but it's a non-cooler transmission... so I decided to put in a more conventional cooler with an electric pump.

I modified a drain plug so I could attach an AN fitting. I also took off the end cap of the transmission and tapped a hole for another fitting (where the stock cooler returns).

Luckily, this car already had the spare tire well removed, so I didn't have to do any of that. I did have to cut two rectangular holes in the blanking plate that was installed... and I had to make some brackets/studs to hold the cooler (RX7 oil cooler) and pump. I thought long and hard about how to get airflow over the cooler, and decided on putting NACA ducts in the side windows and then duct that air over the top of the cooler so it exits under the car. E.g. I'm hoping the air moves from a high pressure area to a low pressure area.

The pump is a gear-driven oil scavenge pump... hopefully it's up to the task.

Then I did a little tin knocking and made up a baffle that will help seal the cooler so the air goes where I want.
Attached Images      
Old 01-30-2012 | 12:58 AM
  #2  
Van's Avatar
Van
Thread Starter
Rennlist Member
 
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
Default

Once my baffle was in place, it was time to put air ducts in the trunk - again, these will direct air to the top of the cooler. I think this will still give me enough space in the trunk for my gas cans (a convenient place to put then when I trailer to the track).

And, finally, how it will be with the RX7 oil cooler in place. (I still need to make up the plumbing and finish the wiring.)

I think it'll do the trick!
Attached Images    
Old 01-30-2012 | 01:47 AM
  #3  
pa944red's Avatar
pa944red
Rennlist Member
 
Joined: Jun 2003
Posts: 767
Likes: 1
From: Mt. Holly, PA
Default

Looks good.

It appears the pump is above the trans output, any concerns with it loosing its prime?

Tom
Old 01-30-2012 | 03:26 AM
  #4  
odurandina's Avatar
odurandina
Team Owner
 
Joined: Oct 2009
Posts: 28,704
Likes: 213
From: one thousand, five hundred miles north of Ft. Lauderdale for the summer.
Default

Good work Van.
Old 01-30-2012 | 09:04 AM
  #5  
Van's Avatar
Van
Thread Starter
Rennlist Member
 
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
Default

Originally Posted by pa944red
Looks good.

It appears the pump is above the trans output, any concerns with it loosing its prime?

Tom
Yes - I'll have a check valve after the fitting on the drain plug.
Old 01-30-2012 | 10:56 AM
  #6  
Lemming's Avatar
Lemming
Nordschleife Master
 
Joined: May 2004
Posts: 6,426
Likes: 87
From: Altered States of America (B'ham)
Default

Looks great, let us know how it works? I assume you will be adding a thermostat?
Old 01-30-2012 | 12:07 PM
  #7  
Van's Avatar
Van
Thread Starter
Rennlist Member
 
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
Default

Yes, I'm going to put a thermostatic switch on the transmission (that's what the green wires hanging down are for). But I'm a little unsure what temp setting to go with... I have a switch now that's 140 degrees...
Old 01-30-2012 | 12:25 PM
  #8  
V2Rocket's Avatar
V2Rocket
Rainman
Rennlist Member
 
Joined: Jan 2007
Posts: 45,606
Likes: 674
From: Nashville, TN
Default

looks good. i'd be interested in knowing how the RX cooler works with the thicker juice of the transmission oil. are you measuring trans fluid temperature with sensors? i have a factory cooler on my trans that i'd like to get rid of if there were a better option such as this.

what size lines/fittings are you running? the factory cooler cant be more than roughly a -10 or -12
Old 01-30-2012 | 02:32 PM
  #9  
xschop's Avatar
xschop
Rennlist Member
 
Joined: May 2009
Posts: 2,728
Likes: 11
Default

Great pics Van. I am going to install a laminar flow double-pass radiator on the trans to keep the install simple. From experience the viscosity of the gear oil is too high for some of the radiator designs that have thin tube wall.
Old 01-30-2012 | 03:02 PM
  #10  
LuigiVampa's Avatar
LuigiVampa
WRONGLY ACCUSED!
Rennlist Member
 
Joined: Nov 2011
Posts: 15,146
Likes: 4,671
From: PCA Gulag
Default

I'm curious if you got a temperature of the fluid before you did this work so you could see how much it went down? Awesome work.
Old 01-30-2012 | 03:14 PM
  #11  
Hollywood D's Avatar
Hollywood D
Burning Brakes
 
Joined: Oct 2010
Posts: 954
Likes: 0
From: Denver
Default

Top notch work as always
Old 01-30-2012 | 11:29 PM
  #12  
car_slave's Avatar
car_slave
Pro
 
Joined: Apr 2003
Posts: 680
Likes: 0
Default

Exciting project.
I was just surfing the web and found a kit for a 911 which might work - I'm sure your's was cheaper.

http://www.patrickmotorsports.com/part/1690/
Old 01-31-2012 | 12:57 AM
  #13  
Van's Avatar
Van
Thread Starter
Rennlist Member
 
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
Default

Originally Posted by V2Rocket_aka944
looks good. i'd be interested in knowing how the RX cooler works with the thicker juice of the transmission oil. are you measuring trans fluid temperature with sensors? i have a factory cooler on my trans that i'd like to get rid of if there were a better option such as this.

what size lines/fittings are you running? the factory cooler cant be more than roughly a -10 or -12
-10AN


Originally Posted by LuigiVampa
I'm curious if you got a temperature of the fluid before you did this work so you could see how much it went down? Awesome work.
I don't have a temperature record yet... but I'm thinking of getting some of these: http://paperthermometer.com/pages/indust.html#8temp


Originally Posted by car_slave
Exciting project.
I was just surfing the web and found a kit for a 911 which might work - I'm sure your's was cheaper.

http://www.patrickmotorsports.com/part/1690/
Yeah, I was looking at that. I probably have $250-$300 into it.
Old 02-03-2012 | 03:59 PM
  #14  
Van's Avatar
Van
Thread Starter
Rennlist Member
 
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
Default

I got the lines hooked up.

Next step is to run power to the motor and check for leaks.
Attached Images  
Old 02-11-2014 | 08:18 AM
  #15  
Thom's Avatar
Thom
Race Car
 
Joined: Mar 2002
Posts: 4,329
Likes: 41
Default

Bump... What kind of oil temp are you seeing and how has the pump been standing the heat?



All times are GMT -3. The time now is 05:18 PM.