Transmission and Supercharger Oil Cooling Design

[JohnJL]

Looking for help designing a cooling system for the transmission and supercharger. Although the manufacturer doesnt mandate a cooler, the supercharger runs super-hot. The last one failed and I'm still in dispute with the manufacturer over the cause but they arent claiming heat.

The transmission is a pricy bit of kit, a built, shortened G50 with a Guard LSD.

Both components support the car putting out around 400hp at the wheels. I already have a transmission temp gauge on the dash.

I've never designed or installed one of these so I'd appreciate some pointers. I was planning on the following additional details;

-8 lines
ECU to turn on the pump as soon as the car is running (since in this design the Transmission acts as the sump and the supercharger will be nearly empty when cold, though I could choose a mid-point drain location to mitigate this)
Sightglass on the supercharger to verify oil level

Suggestions?

[DUK]

Just my opinion... Do you really want to use gear lube in the supercharger? Also I would put the filter in between the trans and the pump. And maybe one where you have it between the supercharger and the trans. And now that I say that, do you really want hot oil coming from the supercharger going to your high dollar g50?

[JohnJL]

Originally Posted by DUK

Just my opinion... Do you really want to use gear lube in the supercharger? Also I would put the filter in between the trans and the pump. And maybe one where you have it between the supercharger and the trans. And now that I say that, do you really want hot oil coming from the supercharger going to your high dollar g50?

Thanks, and good questions. My initial thoughts were that since the transmission is the lowest component, its easiest/best for the pump for it to be the "start" of the system. The flowrate of 1-2 gallons per minute should provide enough throughput that the supercharger won't "superheat" the oil anymore. Also, the supercharger isnt sensitive to oil temps whereas the transmission is.

As far as the lube, the supercharger gear assembly is just a set of straight-cut gears engineered (the manufacturer says) to live on self-contained engine oil. I'd think a cooler, filtered and continuously-circulating supply of oil (redline) designed for gears would be best.

Happy to hear if I'm off or alternative flow designs. THanks!

[JohnJL]

Is this what you mean?

[DUK]

[sc_rufctr]

John

I like the unique approach and it would work but why re invent the wheel?

Why not use a traditional set-up with a dedicated cooler for the supercharger using engine oil as the lubricant?
I think the gearbox oil may be too thick for the super charger gears at high RPM.

What weight oil does the manufacturer recommend for the super charger?

[RarlyL8]

I also think that the engine is a better source of oil for the supercharger. Much more cooling capacity and proper grade oil. The tranny is best left alone as it will be working harder than stock to support 400whp which creates more heat as well. Any track use would heat up the tranny fast trying to cool itself and a supercharger.

[JohnJL]

Originally Posted by sc_rufctr

John

I like the unique approach and it would work but why re invent the wheel?

Why not use a traditional set-up with a dedicated cooler for the supercharger using engine oil as the lubricant?
I think the gearbox oil may be too thick for the super charger gears at high RPM.

What weight oil does the manufacturer recommend for the super charger?

Hi Peter,

I was looking to incorporate the supercharger into the tranny cooling because I am planning on installing a cooling system for the transmission anyway and it would be opportune time.

The manufacturer says the supercharger is fine with its self-contained oil supply, but they also endorse (and Corky Bell advocated) adding a separate supply.

Autorotor recomend a thick grade of engine oil, though they aren't specific.

[JohnJL]

Originally Posted by RarlyL8

I also think that the engine is a better source of oil for the supercharger. Much more cooling capacity and proper grade oil. The tranny is best left alone as it will be working harder than stock to support 400whp which creates more heat as well. Any track use would heat up the tranny fast trying to cool itself and a supercharger.

Thanks Brian. I have not done any calculations but I would think the supercharger and transmission would be fine from a temp standpoint? There are 2 litres of additional coolant, and a derale cooler with a dedicated fan. If the supercharger is supposed to be fine with no external cooling and the transmission is not overheating, then they would be OK?

[sc_rufctr]

Originally Posted by JohnJL

... If the supercharger is supposed to be fine with no external cooling and the transmission is not overheating, then they would be OK?

Your logic is sound...

As I said I like your unique approach.
I'm interested to see how this works out.