tranny cooler questions -UPDATED, ...like...how, what, where??? Options

[naro914]

Hey all,
so it's become obvious to me that I need a transmission cooler set up. With 330 hp and using a 901 box, it's going to start destroying gears (already did this past weekend at Road Atlanta).

So, what is everyone using and how are they set up? What pump & cooler? are you using a resevior/tank? Where is the cooler mounted? and where are you getting the oil in and out of the trans?

As you can see, I'm a complete newbie about this, need to educate and do as quickly as possible...I'm running out of transmissions!

Pictures would be wonderful...

thanks!!

[mepstein]

Sounds like a 930 trans is in your future.

[naro914]

Sounds like a 930 trans is in your future.

Huh? Why would I want a 4 speed? As it is, I wish I had a 6 speed.

[Richard Casto]

Bob,

Here is a recent thread that you might find useful...

http://www.914world.com/bbs2/index.php?showtopic=161520

Richard

[Cracker]

Nah. Bob doesn't have enough torque/power for "just" a 4-speed with big gears. (IMG:style_emoticons/default/unsure.gif)

Is this a clear enough pic (below)?

Forgot to answer the product questions. Tilton pumps & Mocal/Setrab coolers. (IMG:style_emoticons/default/biggrin.gif)

Sounds like a 930 trans is in your future.

Huh? Why would I want a 4 speed? As it is, I wish I had a 6 speed.

[pcar916]

I'm going through the same decision process now. A related thread that has a long discussion on cooler parts and considerations... my pump choice wasn't either of those...

http://www.914world.com/bbs2/index.php?sho...161520&st=0

I'm looking at the huge space in front of the passenger side rear tire because the weight will be forward, low and power is available in the harness a couple of feet away. If my oil tank were up front (possible future project) I'd put it in the left side instead. There is room for a 7in Spal pancake fan, mounting brackets, and a bit of duct-work/rock shielding too.

The six exhaust makes it too hot in my book to mount the cooler and pump below the trunk unless it's got long, completely enclosed ducting and I like fabrications as close to simple as I can get.

[pcar916]

Nah. Bob doesn't have enough torque/power for "just" a 4-speed with big gears. (IMG:style_emoticons/default/unsure.gif)

This car is gorgeous.

[mepstein]

Sounds like a 930 trans is in your future.

Huh? Why would I want a 4 speed? As it is, I wish I had a 6 speed.

Because i'm thinking at 330hp, and racing the car, you're on the very edge of the 901 trans capability. Even with all the mods you plan. So you put big bucks into all the extras, spend a lot of money to get to a race and still blow the trans. Then what do you do at the race? Put in another 901 without all the extras? The 930 trans might not have all the gears but at least (from what I read) was designed for the kind of HP you are working with.

* I have no race car or mechanical experience.

[J P Stein]

Just my opinion with some assumptions on my part but this is the way I would spend my money and why.

When you start blowing off the R & P of a 901 a cooler will help alleviate that but when you start blowing off teeth of gears you are just putting too much power thru the trans....a cooler may help but I doubt it. I believe the mainshaft bows away from the pinion shaft.

I'd do the 930. Sure, it's a 4 speed but has a usable 1st gear whereas the 901 1st is useless as tits on a boar. The straight H shift pattern makes 1st a snap.
All the gears are larger/stronger including the R & P. It will handle more power that the 915.....which is why it was made.

The R & P needs to be flipped
and the shifter needs to be redone.....all not cheep. I hear it doesn't shift as quickly as the 901 because it has the same rube goldberg syncro arrangement as the 901 but more rotating mass.....all trade offs but it will be there for the long haul.
WAG on cost 5-7K.

When you get into the power zone that you're running the trans selection is limited for less than 12-15K.

[Cracker]

The R & P needs to be flipped...

When you get into the power zone that you're running the trans selection is limited for less than 12-15K.

I don't think this is the best idea for Bob/Naro. I have a 930, flipped ring gear, cable shifter, yada, yada, yada. It's a super big $$$ committment - my swap was on a budget build and it still cost 11k (and this is getting great deals!).

But in order to really make use of 930 gearing, a car needs big power. Even 930 turbos swap the trans for G50's because they don't even have enough guts for the gears. You really need 400 at the wheels for it to be a great fit - Bob's car is not in the ballpark, power wise. I think he would be very dissapointed in such a swap with his driving aspirations.

The challenge is where the line is drawn and he's approaching it. I'd suggest a well prepped/built 901 with all-the-fixins which is the direction he's headed. All this being said, he knows what he's going to do and how to do it - he's a racer!

[mepstein]

http://forums.pelicanparts.com/porsche-911...saxle-sale.html

[Steve]

There are some pictures on how Ottos set up mine in the classified. The pump and puke bottle are mounted in the trunk.
http://www.914world.com/bbs2/index.php?showtopic=177014
I will try to post some more pictures of the cooler. I thought he did a nice job!!

[naro914]

OK, so here's the current "plan".

I'm sitting on 3 901 tranny's - only one has the LSD (actually, 4...one is now for parts missing a 4th gear). I'm going to put an oil cooler/pump in - already had a cooler from somewhere (been sitting in a box in my parts bin) and just got a Tilton pump. Going to install fittings on two of the transmissions to accept the cooler lines. The one with the LSD will stay on the car, one without will stay in the trailer in case we need to do a swap.

We'll see how this goes. If I quickly go through one - or both - of these, then we'll go to Plan B...

so, anyone else got pictures of your cooler/pump set up?

BTW Cracker...VERY nice. Got more pics and details of the car you can send me? send to naro@carolina.rr.com

thanks

[Cracker]

BTW Cracker...VERY nice. Got more pics and details of the car you can send me? send to naro@carolina.rr.com

thanks

Thanks...but misdirected. The pictures I posted are NOT of my car...I took it from Patrick Motorsports site. Below is a pic of my 930 trans just prior to install...no cooler necessary for my set-up.

Regarding trans coolers from what I've seen/heard from my SCCA racer friends.
1) Unless you are running at least 25 minute (full on sessions) a cooler is most likely not necessary.
2) Make sure you also run a thermostat 'cause it can take a long time to get gear oil up to temp.
3) Ideally, setting up a trans for a cooler is more than just running in and out...directed internal "squirters" are most beneficial in getting lubrication to the critical bearings, etc.

[naro914]

any more pictures? Finally going to get around to doing this...

No, I'm not going to a 930, so lets stop that discussion.

Looking at the pic from Patrick, I don't see a reseviour, and what is the red section right after where it attaches at the the drain plug? (I'm not in a place I can repost the picture)

Also, can I assume you need some sort of temp switch to turn on the pump once it starts to get warm? (and not run it when the oil is cold)

And....how do you fill it with oil? if you do it the 'normal' way, you lose oil that runs through the lines, pump and cooler, which will lower the oil level in the trans.

[Cracker]

I agree and I don't know. (IMG:style_emoticons/default/drunk.gif)

[Matt Romanowski]

The red thing is probably a filter.

No need for a reservoir. You can probably detach the hose that attaches goes into the original filler and fill the transmission. The cycle the pump and it will fill the lines, then refill. Repeat until it's either full or darn close. With the pump running and spraying the gears, you probably need less oil than you would think.

[naro914]

Thanks Matt.

Missed you here at Parade...you probably already know the news from Jay! :-)

[pcar916]

I used the method above and it worked just fine (details below. There are two things about the system that keep the cooling circuit from dumping the fluid back into the trans while stopped. My cooler is mounted vertically so that the inlet and outlet are on top and I have a 2-psi backflow valve at the geared (self-priming) pump.

I added nearly a quart more fluid to fill the entire cooling system.

My sequence:
1. filled the tranaxle like normal (I have a hole in my trunk floor that lets me run a funnel/line into the fill hole) The trunk-hole is then plugged with a rubber stopper.
2. disconnected the inlet line and pointed it at a catch-can on the floor
2. ran the unprimed pump until there was a steady stream of fluid out of the inlet line
3. turned the pump off and made sure the only line dumping into the case after the pump was turned off was the return line from the cooler to the case.
4. reconnected the return line and added (as it turned out) 15.5 oz more fluid.

Total line used was about 14 ft.
Total oil capacity ~3.75 quarts

Most have seen it but pix are on page three in this thread starting at post #50.

http://www.914world.com/bbs2/index.php?sho...61520&st=40

Good luck!

[naro914]

OK, I lied...haven't gotten to the cooler yet. But soon, I promise!

Ron, do you have a temp/thermostat switch or something to turn on the pump? I guess what I'm asking is, what triggers the pump to turn on? I would assume you don't want it on when the gear oil is cold - too "thick" then, right?

thanks again!