Diff Cooler, how do I know I need it?
 

Sorry if this is the wrong place to post, but I saw a thread about oil coolers and figured it's worth a shot.

Knowing you need an engine oil cooler is pretty straight forward when the temp gauge rises and the RPMs get limited. How do I know if I need a rear differential cooler though?

Thanks.

if it aint broke...dont fix it!
u probably dont need one, but maybe the track guys on here can say more.

You're probably right....so far I don't need the engine oil cooler either. Just curious how to know your diff needs better cooling.

Otherwise I'm going to focus on more functional changes for my Chicago Z...like heated side mirrors.

I can't know for sure, but I didn't notice any change in the steering at any point during my last track day.

And its definitely not the right forum section.

Figures it's wrong, but there are other oil cooler threads that haven't been moved. Doesn't really fit any specific section...maybe the DIY

no no.... its good that its in the engine section. But not under forced induction...

Its a diff cooler... would've been fine in the main engine/drivetrain section.

When your diff blows up all over the track, you know you needed it. :tup:

Honestly, whether this thread is in the right place or not, I'm thinking about it too. My thought is that if you're not tracking the car, don't worry about it. If you are, it's probably worth getting one (or just step up to a new diff, which is what I'm seriously pondering). Nissan didn't put them on their press cars for no reason...

Maybe the best option is to just leave it as is, let the stock diff melt down, and replace it when it does...

Anyone know how much a quaife costs fully installed?

When the diff oil gets too hot on a viscous differential it will have less lock up ability. Had the same problem on my G35, it was like driving an open differential when it got too hot. You will only notice it after repeated auto-cross runs or extended track sessions. Given that your engine would probably overheat first, it's probably not a problem.

The NISMO diff cover has cooling fins and provisions for cooler lines. They cost about $150. Some of the magazine demo cars had them, but for everyday, mild track driving you should be fine.

I saw this in a JDM Z34

http://www.the370z.com/engine-drivet...ear-cover.html

Thanks. Thats the one I was thinking of...

My diff felt like an open diff toward the end of each session last weekend. I'm changing the fluid and going to run it again and specifically look at diff action at the beginning and end of each run to see how heat is effecting performance of the VLSD. Looking at the GTM cooler kit pricing (over a grand), I think I may just upgrade to a mechanical LSD.

The majority of the reason for the overheating issue is due to the tolerances things come preset at from the factory. There is a fair amount of variation, that really should be tighter, but for an OEM part being used in normal driving conditions, its not much of an issue. The OEM diff is absolutely useless once things get hot, and it's lockup% is not all that significant in the first place. It's why the aftermarket units provide an immediate, noticeable difference.

The diff cooler certainly helps on a full out race car running slicks. It's not something I'd invest in otherwise

I expect to buy a clutch type diff. after the stock diff blows up on the track. I hope the stock diff. can at least handle 1 or 2 track days...we will see.