915 oil cooling

[gliding_serpent]

I have been thinking about transmission oil cooling for my 3.4 conversion with 915 (street and HPDE use).

A euro style mechanical cooler seems like the most sense, but then I can not find it in the PP catalog. I am also wondering if this will work with aftermarket reinforced diff side plates and guard LSD (I suspect not, and I am getting both)

Patrick motorsports builds an oil cooler but I have yet to research on how and where it mounts (I have sent them an email). G50 930 915 911 901 Transmission Oil Cooler System - Trans Gearbox By Patrick Motorsports Porsche & Mid Engine Performance Specialists

Wevo builds a unit, but it is a bit $$$ for me.

Thoughts or experiences would be appreciated.

[Drisump]

Sorry, no input on your selection but I think getting a cooling system for a more powerful, 915 powered car is a good idea. I have a 915 powered Euro (with 231 HP) and the factory thought it necessary to install a cooler. I take from that, the factory believed that the 915 coupled with a 231 hp engine was at the edge of it's power rating for a production road car. I'm thinking your 3.4 would likely put out at least 250 hp? Cheers

[Matt Monson]

Our LSD does have mounting allowances for the drive gear of a Euro pump and cooler kit. Finding one for sale is another issue all together.

Aftermarket sidecovers don't have mounting allowances for the pump or cooler. However for a track car one of the aftermarket ones, like Patrick's will offer better cooling than the street car version.

Regards,

Matt Monson
Guard Transmission LLC.

[tshebib]

I installed a Tilton pump in the engine bay and the cooler is attached to the deck lid. I often wonder if this is optimal because there is no fluid in the lines or the cooler when the pump is not on. Once the pump turns on the oil level in the 915 is now effectively lower. I would love to hear any thoughts on this. I looked underneath on either side of the tranny for a possible location but it's really tight and I wimped out. The Wevo solution looks perfect to me as they solve the space issues, created a "scoop" to pick up some air flow and the fluid level in the tranny will stay the same whether the pump is running or not. The PMS solution I believe assumes you are cutting a hole in the back seat and pulling the air from inside the car. Ideally I think it would also be nice if you didn't have to disconnect the cooler, etc. when R&Ring the engine/trans. Here are some links to help confuse the issue


http://forums.pelicanparts.com/porsche-911-technical-forum/776106-gearbox-oil-cooler.html

The 915 Transmission Case | Rennsport Systems | Porsche Performance Systems and Support

http://forums.pelicanparts.com/porsche-911-technical-forum/630433-915-rebuild-3-6-oil-cooler-suggestions.html

http://forums.pelicanparts.com/porsche-911-technical-forum/597460-915-cooler-setup.html

911 Transmission Cooler for a 915 Transaxle

http://forums.pelicanparts.com/porsche-911-technical-forum/318439-transmission-cooler.html

http://forums.pelicanparts.com/porsche-911-technical-forum/213609-915-cooling-help.html

Pics of my setup

[spuggy]

Originally Posted by gliding_serpent

I have been thinking about transmission oil cooling for my 3.4 conversion with 915 (street and HPDE use).

Spray bars pump returned oil into the gears. I'm told the factory used them on every racing box (and that all the 915 castings have provisions for the spray bars), despite the load the pump added (apparently 10-12 HP) - even on older motors making less than 200 or so.

Cooler reduces oil temp - which can prevent oil/additive breakdown, I believe.

I think both are great ideas. as power rises, or usage conditions get more extreme. In one of Jack O's videos, seem to recall he manually switches on the cooler pump when tranny oil temp gets over 200 after 2-3 laps...

Aftermarket billet covers don't have provision for the mech oil pump - but should be stiffer/stronger than even the latest/last factory cover with the pump AND take the 930 bearing/seal instead of the 915 one.

Mech pumps take HP to drive them - all the time - whereas electrical pumps take that from the electrical system (e.g. battery, probably adds load to the alternator), but can be switched off when not required (e.g. thermostatically-controlled).

For HPDE with over 300 ft/lbs, I'd probably lean towards a billet cover.

[gliding_serpent]

Tom, we should talk. I made assumption with the patrick cooler. I was thinking something to the effect of a scoop diverting air to the cooler underneith everything.... But i did not think about this hard enough i guess. I am about to pull the trigger so will call you tonight if that is alright.

I installed a Tilton pump in the engine bay and the cooler is attached to the deck lid. I often wonder if this is optimal because there is no fluid in the lines or the cooler when the pump is not on. Once the pump turns on the oil level in the 915 is now effectively lower. I would love to hear any thoughts on this. I looked underneath on either side of the tranny for a possible location but it's really tight and I wimped out. The Wevo solution looks perfect to me as they solve the space issues, created a "scoop" to pick up some air flow and the fluid level in the tranny will stay the same whether the pump is running or not. The PMS solution I believe assumes you are cutting a hole in the back seat and pulling the air from inside the car. Ideally I think it would also be nice if you didn't have to disconnect the cooler, etc. when R&Ring the engine/trans. Here are some links to help confuse the issue





Gearbox oil cooler



The 915 Transmission Case | Rennsport Systems | Porsche Performance Systems and Support



915 rebuild for 3.6, oil cooler suggestions



915 Cooler Setup



911 Transmission Cooler for a 915 Transaxle



Transmission cooler



915 cooling help



Pics of my setup

[tshebib]

Also, There's the question of switching. I tapped into the rear window defogger relay in the engine bay. When/if I remember, I just have to pull the switch on. Ideally it would be nice to have a thermal switch installed somewhere on the tranny but there is very little info on the details of how/what to do to set that up. Call me anytime to discuss.

[gliding_serpent]

A non-return valve in the oil cooler circuit is key. Should solve the dry issues when not in use (depending on how you mound the cooler). The flip side of that is that having cold trans fluid in the cooler will stress the pump on startup as swepco is thick. I think my balance may be to have short lines and my cooler as close to the tranny as possible.

Also, PMS sells a thermo switch that can run inline with the oil lines. When it is at 180 degrees F it will turn on the pump (if I understand correctly).

In-Line Thermal Switch Assembly AN08 By Patrick Motorsports Porsche & Mid Engine Performance Specialists

the cooler and pump
G50 930 915 911 901 Transmission Oil Cooler System - Trans Gearbox By Patrick Motorsports Porsche & Mid Engine Performance Specialists

This will run to my center console (that will also house an AEM wideband analogue afr gauge that I will tap to the O2 sensor port on my SSI's)
Oil Temperature Gauge & Sensor Set - Engine - Transmission M14x1.50 By Patrick Motorsports Porsche & Mid Engine Performance Specialists