86 951 Driver

Does it serve a big purpose? Stock cooler BTW.

OntarioTurbo

In discussion with Marcus Blaszak he says for a street car it means nothing. If you were to track the car regularily it might make a difference. I believe the coolers were no longer standard equipment in '87. Anyone?

I have been thinking on swaping my '86 turbo tranny with cooler for a rebuilt '87 turbo tranny w/o cooler, but I am reluctant to give up the original tranny because it is original to the car. Thoughts anyone?

User 52121

I know our Lemons car ('86 N/A) did not have a trans cooler in it. We flushed the trans fluid at the end of the first full day of racing on Saturday as the trans was starting to make noise - and the fluid that we drained out of the trans (about an hour after we pulled the car off the track) was every bit as hot as the engine oil was. So I'm sure it makes a difference at least when running the car on the track - moreso I bet for a turbo.

Tedro951

Yep

PorscheDoc

IMHO not really needed for a street car. Heavy track use...definitely.

docwyte

I'd really like to retrofit one to my current S2 tranny.

Any thoughts on how to do this? Is there an aftermarket bolt on kit? I know the factory ones have parts NLA, particularly the large lsd gear drive gear...

samluke

Similar experience to OmniGHL, we ran an NA Chump car at Hallett in 2010. The tranny got so hot, it melted the sound deadening off the trunk floor. Tranny ran just fine though, nevertheless.

Worthwhile for the track, limited need for the street.

Musche

Definitely needed for a track car. After a half hour of track driving the gear oil gets above 200 degrees. (sometime take the temp of the case with an IR temp meter and you will see what I mean). A friend of mine who rebuilds 944 gearboxes tells me the heat causes the case to expand and can spin the conical main bearing race basically ruining the transmission much like a front hub failure. I have added a cooler to my transmissions by removing the lower drain plug and replacing it with a M22x1.5 to 10AN adapter fitting and routing thru a screen filter to electric Genesis lube pump to a 9x9 cooler with electric fan that is mounted above the muffler shield and then back into the tail shaft where a factory coil would return. Right now the whole rig is on a master switch but I plan on putting a surface mounted 100 or 150 degree thermal switch from a fireplace blower to activate a relay so the whle thing works automatically. Just like any other lubricated machine the cooler it is the longer it will last. Just a thought....

Tedro951

Doc, Olli did one. Paging Olli!

FWIW, I'm not sure if the cooler is absolutely necessary on a street car, but if Porsche could've saved the $$ on the 86, I think they would have. Actually, a street going 951 could probably do without the engine oil cooler. THAT ought to start another thread altogether!

Its funny that listers sweat over what high dollar lube to use, then are willing to concede the necessity of the cooler.....

FRM

The reason that Porsche had trans coolers on the 1986 models was that in the 944T was competing in the SCCA Showroom Stock series, basically against the Corvette. I believe the rules for 1986 were that the car had to be stock and equipped with only standard equipment and possibly priced below $30,000. So if the 944T needed an oil cooler to make the trans. last thru the race, it had one....std equipment. The 944T won the championship in 1986. In 1987 I believe the rules were changed, so no more standard trans. cooler on the '87s. Anyway that's what i recall when I bought mine in 1986.

I wouldn't apply the same reasoning to the engine oil cooler. There are a lot of cars that don't normally see the inside of a race track that have come equipped with engine oil coolers including several Volkswagen models, some Turbocharged Volvos, some police interceptor and high performance models of domestic cars. In view of the cost of an oil cooler, I don't think the manufacturers would put them on if they didn't need 'em.

V2Rocket

these are great little coolers made by setrab...nice size, good quality pieces. they are what you get in a KISS kit but with smaller fittings..

Tedro951

The SCCA thing makes sense, but the external engine oil cooler falls into the same category. A street 951 that runs around on 1 or 2 psi all day, with an occasional 5 second burst to 15psi probably has oil temps barely hotter than an NA, which has no external cooler. I'm keeping my trans cooler, engine cooler, power steering cooler, brake ducts, intercooler, and 4 piston calipers.....none of which I need more than 1% of the time on the street.

Its really not worth debate, though. The OP is probably happy with the "no cooler required" results.

JohnKoaWood

Olli is on a temporary vacation, not sure if he is planning to remount Rennlist or not..

YES trans cooler can be retrofit, YES it can be done without the OEM pump or fittings, your pickup point for the pump is the drain plug, with the return drilled and tapped into the rear housing of the trans, or any number of other spots available.....

I plan to add a stock cooler loop and LSD to my 87 turbo trans as part of its build, already have all the pieces needed on hand, just need to get my N/A together and out of the garage, so the 951 can come in and make some progress.. my car is 99-100% sstreet use, but it does get some wicked street use... and distance driving is involved... did I mention I put 15K on my N/A in 5 months... and over 20K on my 951 in a year?

TonyG also did an alternative solution IIRC... electric pump, drain plug pickup, aftermarket cooler, 80mm fans on the cooler, drilled and tapped rear housing...

Tedro951

Dang! That's racking up the miles! I missed Olli's hiatus...

Lemming

Another option.

http://www.porschehybrids.com/galler...Cooler-Upgrade