Manual Transmission Cooler

[Sasha]

What do you guys do to cool your manual trannies? Are there manual transmission coolers? I guess they woudl work with some sort of external pump, since there is no pressure inside a manual tranny to flow oil to and from the cooler.

If there isn't anything im thinking about peicing together an electric pump system to a cooler and back to the tranny

input and advice would be greatly appreciated thanks guys

[John Powell]

My first comment would be a question - why do you think you need one? A good high performance gear oil such as Red Line HD Shock Proof Synthetic should be able to handle gearbox temperatures in any smaller production-based race cars. The only production-based cars I've seen that need tranny oil coolers are those with highly modified, high torque and horsepower V8/V10/V12 engines. Also, if you need a tranny oil cooler you'd probably nead a differential cooler too, and these are extra plumbing jobs that you'll have to prepare and maintain. Maybe you should get an idea of the temperatures you're getting first, and if you can't plumb in a temperature guage (which you'll need if you put in a cooler as over-cooling could be an issue too) there are temperature-sensitive stickers available that you can stick on the transmission and rear end housings. Oh yeah, and that'll mean yet another guage (or two) that you'll have to check while driving in competition. More stuff is not always better.

[Sasha]

haha thanks for the input john, believe me with my budget LESS IS BEST

but my car is producing about 330whp and around these power levels they are known to break gears. ADAM with a solo 1 car of similar power has blown a couple gearboxes himself if i remember correctly. So a tranny cooler (esspecially for the longer races) is really needed.

I agree that overcooling would be a problem as well, but since its strictly a race car I don't think i'll have to worry about it to much unless I'm racing in very cold conditions! Maybe I should put some sort of thermostat inline. Maybe if I was using an electric pump I could have it run off of a temperature probe that went into the transmission, when it gets above x temperature the pump comes on and starts to circulate the oil in the transmission.

I guess the problem is a weak transmission more than a ton of torque. Nissan really didn't build this car to be a race car

[rmicroys]

Many transmissions can't take the heat. My VW 020 transmission is probably okay up to about 150whp for longer endurance races... but after that it has to be cooled. Then I either have to step up to a different OEM setup, or cool the one I have. Very easy to do. Get a tilton oil pump, any kind of good transmission oil cooler, and some hoses/fittings.

[Slowpoke]

I've thought about this myself, but it's lower in the list of priorities at the moment.

The 6-speed in the Subaru STi is supposed to be bullet-proof. However, I noticed that around the Mosport GP track that the feedback on the stick wasn't as crisp towards the end of the run. It felt sloppier and I would occasionally grab 3rd when I wanted 5th. (Yes, yes, maybe it was ME getting sloppier. But I'll blame the transmission heat to save my pride.) If I had dumped the clutch, that would have been a "boom".

If you find a commercial system, please post the manufacturer here!

Fluid: Motul Gear 300 75W90 with a touch of PA90 for better synchro engagement.

[rmicroys]

These guys make a diff oil cooler kit. The same technology can be used to cool the tranny too...

http://www.arcinter.co.jp/arc/products/oil/deff.html
http://www.mackinindustries.com/md/a...ssionoilc.html

[John Powell]

Originally Posted by Sasha

but my car is producing about 330whp and around these power levels they are known to break gears. ADAM with a solo 1 car of similar power has blown a couple gearboxes himself if i remember correctly. So a tranny cooler (esspecially for the longer races) is really needed.

With those kind of issues, you're right. Luckily I haven't had or heard of similar issues with 1st gen RX7s - knock on wood.

[P.Po]

A few late 944 Turbo's have a tranny cooler. A very simple and effective design, I believe. They simply tap two holes in the tranny, and install what looks very similar to brake tubing. The tubing forms about 5-6 loops and they are licked by the airstream underneath the car.

Also, check out the diff cooler fins on some of the "M" BMWs.

A high quality fluid always helps!!

Ymmv,
Patrick

[ADAM]

Hi Sasha,

I have only lost 1 gearbox due to overpowering it, and that was at 21psi boost, so it was taking over 400ftlbs torque.... 3rd gear just let loose the teeth stripped right off, it was not being abused or mashed..it just let go at full throttle at a low rpm...and that was that...

never had any failures or problems at sub 400rwhp power levels.... and the diff has been bulletproof so far...

only heat issues are turbo heat issues ..thats where I would spend all your time and money....

[Sasha]

hehe thanks adam! I never knew you were pushing that much power on the tranny thats sweet. Yea I have a bottom mount turbo and I've wrapped the manifold and downpipe with manifold wrap so i'm hoping she'll be ok. I might also open up my hood in that area as well to let all the heat drain out, and a heat sheild around the master cylinder would likely be a good idea

I'm just looking for an oil pump online that is cheap and then i'll order it up and hookup the system i'll be sure to take some pics and show you guys

edit: just found tilton pumps on summit for like 176usd. Sweet. Going to order one real soon

[Sasha]

Well I got my tilton pump from summit racing and a setrab cooler off a nascar car from ebay. A bunch of braided line and some fittings later and we have this!

my masterfully engineered design thanks to MS paint:



And reality:




(cooler on the right is my oil cooler)

[Sasha]

drain and fill plugs welded with -8 fittings



cooler's rough position:



pump and inlet on the cooler:

[Sasha]

lines all done:



and a shot from the bottom. I think im going to make a protective plate just incase anything decides to try and wreak havoc on my tranny this season



and while we're at it, heres a pic of the oil cooler:

[kmorris]

Wow, nice looking setup.

An oil cooler from EBay? Better make sure that puppy isn't full of shrapnel!