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!!

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.

Bob,

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

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

Richard

Nah. Bob doesn't have enough torque/power for "just" a 4-speed with big gears.

Is this a clear enough pic (below)?

Forgot to answer the product questions. Tilton pumps & Mocal/Setrab coolers.




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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.

This car is gorgeous.

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.

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.

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!

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

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!!

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

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.

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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.

I agree and I don't know.

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.

Thanks Matt.

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

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!

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!

The pump is simply controlled with a toggle switch on the dash. I have a rather large gauge (overkill, but I had the roll bar just sittin' there.) down by my shift tower. On the fluid viscosity question...

that pump is powerful and even when cold it still pumps that fluid out at a big rate. As long as the case is vented it's an open system, so the pressures in any hose segment are very low. In fact, there's no need to turn it on most of the time while on the highways and byways except to keep sediment moving into the filter. I'm running it about once an hour for 5 minutes just to keep sediment from building up in front of the pickup (formally drain) fitting.

I got back yesterday from a 600 mile round-trip (55-75 mph) in 98 - 108 degree (F) weather and the system is good for ~15 degrees of without a fan on the cooler... wish I could get that in the cockpit. Bloody hot outside but just too much fun to drive to take one of the cars with AC. Besides, I have nieces and nephews that want to ride and they don't care how hot it is, just which friends see them in a sports car. Pretty funny that.

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Ron,

Sorry if you mentioned this type of info earlier, but on your trip yesterday, you mentioned an approx 15 degree delta when you run the pump. What was the temperature you were seeing when at steady state highway cruise without the pump on?

Thanks,

Richard

I use a three position switch on the dash - ON (Man)/OFF/ON (Auto). In ON(Man) the pump is on always. In ON (Auto) the pump turns on when the trans temp rises above 180 degrees F. I epoxy-ed a small (dime -sized) thermo switch to the side of the transmission which turns on the pump when the temp gets at or above 180 degrees. The thermo switch is normally open and closes when the set temp is reached.

On track I usually see the pump turn on (I have a pilot light indicator on the dash) after about 3 laps. Trans temps stay less than 240 degrees with my set-up. I have seen over 300 degrees before pump and cooler installed and the front trans seal leak along with the high temps.

It varied from ~150 - 180 depending on my speed. That's less than the temps that I saw on the previous transaxle (lost the R&P late last year) and the main reason I'm going to plumb another sending unit closer to the gear cluster/R&P. It might get the same readings but I'm just not sure, and tapping another hole for a sender is trivial.

Until then I don't know if I'm comparing apples and oranges between this box (same internals except for the replacement R&P and a taller 5th gear pair) and the last one, which ran hotter ~200 without a cooler. All bearings are the same.

Interesting to me that it took about 5 minutes at ~2.x gpm flow rate (didn't measure it hot) to bring down the temp. I could've calculated that beforehand but chose to just observe the finished system. This geared pump is rated at 2.6 gpm continuous duty. Another thread that, but important.

I'm buried so unfortunately, I won't get any track-time this year. I'll update this thread on those readings when get them. Seems to be interesting to a few folks.

Speed makes a real difference. Not sayin' I did, but if I were to run at about 100+ mph for a few minutes, I wouldn't doubt that a reading around 200F was possible with the pump running.

I like this idea. On track, I don't want to have to "remember" to turn the pump on....I won't. And neither will my wife. I'd hate to bust a trans because one of us forgot to turn on the cooler!

New question: what gear oil does everyone use? Was thinking Swepco, but would appreciate thoughts from the peanut gallery..

Thanks
FYI, pics coming soon....we're moving along nicely.

Progress Pictures!!
So we decided on the very simple approach: pull oil out of the drain plug, through a scavange filter, through the pump, into the cooler, then back in at one point only, right above the R&P. Simple and hopefully effective.

Pump is mounted in rear trunk.

Cooler is mounted at 45* at the rear bumper, hole cut for pass-through cooling.

the third tap in the case is to extend the vent into the trunk for a catch can or just a filter...not decided on that yet.
Obviously still have to grommet the holes, run the power wire, finish mounting everything, etc. this is just the mock-up. HOPE to have all that done this weekend.

Sorry for the picture quality, did it with the iPhone quickly last night...

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Bob,

Is that sealant of some type oozing out between the intermediate plate and the case? You should only use paper seals there. I know that adding a sealant might help prevent leaks, but it is not going to let you set pinon depth accurately. You can use a sealant between the intermediate plate and the end cover (I use paper + a thin layer of Curil-T). I don't have problems with leakage on the differential side cover (that o-ring seems to work fine). I use Hondabond on things like the breather and clutch pivot ball (where it threads into the case).

Keep us posted on how the cooling system works out!

Richard

Richard,
Lou at Exclusive Motorwerks is who builds my transmissions, engines and pretty much does everything with my cars. He's been building transmissions this way forever, and they never leak or have issues, so it works out fine. It's really only a very thin layer of Dow 730 (some really expensive aircraft grade stuff)... a little dab on the finger and spread it on every mating surface. Uses it for engines too and he's built me probably the only engine I've ever had that doesn't leak anywhere!

We had just rebuilt this exact trans early this year and it was very dry, worked perfect. Then I got the brilliant idea of the cooling and new IP, so apart it came.

I was hoping to run it yesterday, but I ran out of time. Lou wasn't around, but I got all the fittings hooked up, ran the breather line, wired it up to a switch on the dash, and grommetted before I left. I had a bunch of other things to do on the car while he wasn't there anyway, so we'll get it tested out on Monday...

Looks good and simple. Do I remember that you're taking temps at the speedo hole or am I confusing that with another build? You'll have to let us know the temp deltas when you take them. To the fluid...

I've used Mobil-1 and Amzoil both with no measurable difference in either R&P or synchro/dogtooth wear. I'd use LE (Lubrication Engineers) except that I have to buy 5 gallons at a time. About 730...

I don't think paper gaskets and 730 are mutually exclusive, but I've never used it on a transaxle before. I've used it for years and yep, they're proud of it at about $34/oz. but I don't know anything that works better.

If I've done my surface prep right I don't usually have issues with anywhere except the occasional axle-flange seal seepage. Especially since cutting the second o-ring groove into the speedo housing/plug. The only thing I don't like about 730 is cleanup during a rebuild... tenacious stuff that.

Bob,

Thanks for the reply. I am a big fan of using empirical evidence, so if it has been working for Lou, then kudos to him for trying something new and making it work. I think I still would not recommend that everyone do this unless they know what they are doing. I have seen "how to" instructions on these transmissions in which people have used RTV (and other sealants) in place of the paper and I think that was done out of ignorance and not via a proven new method.

My concern (especially for amateur rebuilders) is that if you have to use multiple paper seals to set pinion depth and you also apply a sealant to each layer that it could adding up. That the thicker the sealant the less likely the assembly clamping force is going to squish all of the extra out (seven layer burrito!) And lets face it, the main reason any type of sealant is going to add value here is if you have a buggered up sealing surfaces.

Maybe someday I will dry assemble a case, measure depth, then do the same thing, but with the addition of some type of sealant to see how the depth changes. I would be shocked if it doesn't, but the pinion depth spec does allow for some leeway (you can't expect to achieve optimal depth with just the metal and paper shims), so I can see if you are on the right side of optimal, that some extra sealant might not hurt. But if you are on the wrong side, some extra sealant might actually not help.

Regardless, I love this thread as it is interesting to see what everyone has tried from a cooling perspective and what works and doesn't.

Richard

PS: We live so close to each other, we are eventually going to have to meet some day!

Richard,
No problem. There is the paper gasket in there, and the pictures make the sealant look more than it is, he basically puts a pea sized dab on his finger and spreads it all over the surface. Tightening the bolts down squished out anything other than a micro thin layer.
But I can say this: Lou's transmissions and engines never leak! I am VERY happy about that!!

You wouldn't by chance be going to the VIR ALMS race? We'll be there, staying at Hurricane Region President Kevin Heimbaugh's house in Cary. Not sure if we're bringing Huey or the GT3.... depends on the weather.

I will be there on Saturday with my youngest. I am not sure but I "think" I saw one of your cars at the Porscheplatz (VIR or Road Atlanta?), a few years back. But I didn't get a chance to look for you.

Richard

Huey has been at RA the past few years.

so I was looking at the pictures I posted and damn is the car dirty! The least I could have done was clean him up before taking pictures.

Was hoping to get oil flowing today but no time.

Dirt is patina...

I posted this on another thread, but havent gotten a response yet:

For those using the Tilton pump, how noisy is it? We turned it on to test and it's REALLY loud. Not as loud as the engine, but loud enough to sound like there's something wrong with it.

I thought it was the mounting, but even holding it still against the rubber mounts doesn't change anything. I even thought that once it primed it would quiet down, nope. It's working fine, pumps the oil ver well, but just really loud.

thoughts??

Shades of Facet fuel pumps eh? I was watching that thread as well for an answer. My gear pump is closer to me but I can hear it while it's running too, which surprised me. It growls through the rubber mounts for just a moment while priming and settles into a solid whine.

Intake noise and SuperTrapps make it go away while driving.

It's obvious that transmission cooling is a hot topic (pun intended) because there are so many threads on it.

Wasnt sure which thread I updated on our progress/finish (or if I did at all), but there is info on our facebook page www.facebook.com/naroescapemotorsports

So, everything is installed and was run this past weekend at CMP.

NOTE: We learned that if you install a cooler/pump, you MUST run it! You need to fill the case higher than normal to allow for the capacity of the pump, cooler and lines, so if you don't run the pump, the case is technically overfilled. We had quite a bit of oil spurting out through the vent hose and filter when we forgot to turn it on! oops.

Was also told that using synthetic will help with that as they foam up less. We'll try that.

Finished pictures: (sorry they're not clear, did them with the phone)

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Bob, how did this setup do for your tranny? Did it last longer? Did you break anything over time?

Bob,

I use this... http://www.smittysinc.net/supersyn-gear-oi...-gl-5-gear-oil/

It is for tractor trailers and I was told to by Peter Dawe who built my motor and gearbox. I know you know him. . I also run a cooler setup much luck yours.

Steve

Hi Steve,
Uh...yeah...our car is having the engine rebuilt from Peter now... For the future, I'll do whatever Peter tells me.