At higher fluid:air temp differentials, heat transfer is greater and you will get rid of heat faster (assuming the cooler area and air flow is enough to get rid of the extra heat). Ie, you may be in better shape than you think.

That'd be good.

Pics...

Pump and lines

http://i39.photobucket.com/albums/e1...ps93c1ffe6.jpg

http://i39.photobucket.com/albums/e1...ps8706a266.jpg

Cooler with no scoop yet

http://i39.photobucket.com/albums/e1...psc4f51eeb.jpg

Notched out arm incase diff flexes to much.

http://i39.photobucket.com/albums/e1...ps331bb1ff.jpg

Fill hole

http://i39.photobucket.com/albums/e1...psa3e133de.jpg

Scoop/cage getting painted. Extremely strong so wind can't move it at high speed.

http://i39.photobucket.com/albums/e1...ps969133ba.jpg

Instead of having to look at the gauge to know when to turn the pump on, you should look into getting a temp control switch. Cuts power on when it's at xxx degrees and shut off at xxx degrees. Might take some guess work and cut down on one less distraction on the track.

The pumps good for an hour. Events are probably no more than 30min. I'll probably just run it from beginning to end. A switch isn't bad but having it kick on daily idk.

Just wanted to update this since it's been warm out now. My normal driving diff temps in the summer have been around 210*. I kicked the pump on for a few seconds yesterday and it dropped to 192* but I hit traffic and tuned it off. I can't wait to see real track temps. It's going to be insanely hot.

I was on highway last Saturday night for about an hour average 130mph and got my whole rear bumper covered with LSD oil, now I'm thinking about doing the same thing. I am going to use a 16 row cooler and maybe another 10 row cooler in series since I have them laying around already. How did you come up with this motor? Do you think a higher flow rate motor would help the temperature better?

You can have too much flow. The fluid doesn't spend enough time in the radiator. May not be a problem for you but something to be aware of. Lots of info on heat exchanger design, heat exchanger calculations, and heat exchanger equations on the Web.

That's what I was wondering. I'll need to find out the appropriate flow rate motor.

I am impressed with the thoughtfulness and record keeping on this DIY -- great job!

I may have missed this, but what is the target temp range for optimal performance?

On this matter, I have to confess, I am utterly ignorant, so I could only imagine this in regard to what I know of engine oil, but diff oil undoubtedly has very different characteristics...

If you have a clear target, maybe a thermostat could be incorporated? No need to over cool, which may or may not be happening when switched on.

Either way, nicely done and thanks for sharing! :tup:

sounds like you boiled the oil out the vent tube.

GTM uses it in their $1500 kit!! Tilton makes another one thats heavier and more money but it can be run all day vs just an hour like mine. no i dont think so. the best way to keep it cool is going to be air flow to the cooler, amount of oil, and a good cooler.

i try haha, thanks

in my eyes diff oil should be around engine oil temp or else it will prob break down really fast. ive been told thats 260*. Doran told me once they get up to 300* within 3 laps. now they only race for 45min and im sure they replace after each race. guys like Megan have blown 2 oem diffs up and i bet thats the reason. he races hard and only now after i did mine did he buy parts to do a custom diff cooler. regardless of when the oil starts to break down, i wanted a diff cooler to see if i could race on the VLSD and have it perform. we all know it goes to sh*t when i gets to hot so if i can track at about 240* it might not be a bad LSD to use. but if its 300* like Doran or Megan, then it becomes an open diff and usless.

im sure one could be. since its an hour long pump and track days are 20min at a time, i have it wired to a switch and on with the car on. ill just leave the switch on and never worry about turning it off till i head home. ive let the car sit for hours and the diff NEVER cools down. that 100lbs hunk of iron keeps heat for a long *** time! only in the winter do i notice it takes a long time to reach any heat over 160-170*.

Hmm. That's the engine oil ball park. Sounds like a 200* F thermostatic plate would be ideal, it it can be incorporated easily enough.

I wonder how effective the Nismo finned diff cover is.

Update. So after a track day at mid Ohio my highest temp was 230-240*. Not bad I must say. The factory VLSD might actually be ok in this temp range. I still need to sort things out and push harder, so after I have my rear coils get rebuilt I'll try again and see if the VLSD sucks at all. I believe as long as it stays cool it works.

Now since I was hitting almost 240* I am worried about fluid break down so after a few track days I'll replace it. And yes I know the VLSD has internal fluid which doesn't get replaced. It's just to keep my gears happy.

Glad to see you on the track. :tup:n:driving: