Cooling Rear Diff.?

Double Venom · #1 (**permalink**) 09-01-2002, 08:11 AM

Taking a spin from the Pre-Lube thread got me thinking.

Maybe Bob or Cal can throw some insight into this.

The DV II model is using an inboard brake, quick change rear end.
At the track the oil temp will run right at 245 to almost 300. ( I know, requires a oil change once it hits 275.)

We are installing " marine blowers" on the rear rotors which should help tremendously.

I'm wondering if we use the pump that Perry mentioned, run it through a small tranny cooler we use on our streetrod builds, would it drop the oil temperature down to an acceptable level?

Any other suggestions?

DV

Jack21 · #2 (**permalink**) 09-01-2002, 10:54 AM

Seems to me that diff oil coolers are used on roundy-round cars all the time for the same reason. There is no heat radiating surfaces on the diff, because under normal use, they don't get that hot.

There are little trans oil coolers that come with electric fans that can be mounted in any position. Couple this with an electric oil pump, and a little plumbing and it should drop your diff oil temp.

Last time I visited the coatings shop, they were coating diffs with heat dissipating material on a race car, along with trans cases, oil pans, and brake rotors & calipers.

Double Venom · #3 (**permalink**) 09-01-2002, 12:37 PM

Ron, computerworks sent me some really neat info and pics of an install that......????...... was using.

Jack I know exactly what you are referring to! Our Streetrods use the same set up and I totally forgot about the little fan.

I'll bet this, along with the blowers will really drop the temperature! I'll post pictures of the work when we get into it and then report the results!

DV

RICK LAKE · #4 (**permalink**) 09-01-2002, 04:48 PM

Hi DV Perma-cool sells a maxicool in Summit or Jegs which will work. cames with a fan, all you need is a relay and switch to turn the fan on. Nascar sells a kit to run the pump off the rear differential. yoke when racing. Are you using synthetic oil in your housing? Cobra restorer sells brake air kits for your brakes to get air on the rotors. Are your rotors drilled and grooved to help remove heat and tempature. If you are going to race this hard, maybe you need to go to outboard brake system. Good Luck Rick Lake

Double Venom · #5 (**permalink**) 09-01-2002, 07:07 PM

Rick,
The car was built to run hard. The quick change was mandatory, as well as the inboard brakes. The brakes haven't been a problem, we planned for that, but we didn't really think the rear end would heat up this much.

Personally I don't like cross drilled rotors. Under hard racing conditions each "hole" has a tendancy to spider crack. Got a pair of brand new BAER's, crossdrilled I'll sell you cheap!

I'd like to know more about the pump you are talking about. Any ideas where to look?

DV

Cal Metal · #6 (**permalink**) 09-01-2002, 07:15 PM

This may be too simple a suggestion, but what about synthetic differential fluid?

Double Venom · #7 (**permalink**) 09-01-2002, 07:29 PM

Oops,
Nope, haven't tried synthetic. The rear end manufacturer was very explicit about what oil to use. (Can't remember what it was right now.)

Synthetic run cooler, or simply tolerate heat better? Both?

DV

RICK LAKE · #8 (**permalink**) 09-03-2002, 06:37 PM

Hi Double Venom The rear pump for a quick change rear is in www.1speedway.com I think this is what you are looking for. Why is your car burning up brakes this badly. Is it the car weight,the large motor on the nose, overdriving the car, maybe 14 inch Alcoa brakes are needed in the front of your car? I would think 65-75% of your braking is done in the front. Maybe carbon fiber is needed if you have about 6000K to invest. Are the tempatures on the rotors about the same? I am sure the air gap between the rotors and the pads is OK. Is it possible that your calipers are dragging and not releasing? Does your calipers have a spring to push the pads off the rotors when not being used. I have just trying to help find a reason for this problem. Let me know on the pump, I have to find the other company that sells an electric setup for your car. Someone used a pre-oiler kit for engines with two spray nozzles to cool the carrier bearings and pinion bearings. You can also use brakeline to cool the axle bearings on the end of the tubes. If you get a temp sensor, relay, you can have it go on and off when needed. Hope I helped. I want to come next year to your charity function if time permits. Buzz me if I can help further Rick Lake