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my diff is cooking :(

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Everytime I´m on track my stock helical blows out lots of diff oil cause it gets too hot.

S14 have diff coolers, why don´t we??

Does this S14 diff cooler fit to our diff?
Or do I need the S14 diff housing?

Is there maybe a nice diff cooler kit to purchase anywhere?

What about those larger oil capacity diff backplates?
Do they fit when a Hicas Lockbar is installed?


greetz,
Benne
 
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I changed it last week, now it´s Liqui Moly Hypoid GL4/GL5, 75W90.

But it wasn´t an improvement.
 
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Ive got a tomei 2 way in mine using redline heavy weight shockproof and ive had no issues at all with oil leaking or the diff overheating?


Greddy do a cooling cover for the diff housing but i think the way to go if youre having issues is possibly the s14a pump and diff cooler really?
 

craig8585

I'm so cool, I have my own fan thread :p
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Don't the viscous diffs on the S14's get a lot hotter than the mechanical ones on the 15's, hence the standard cooler?
 
C

cougar power motorsport

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if i am not mistaken i came accross of some companies selling aftermarket diff cooler. If not you can have a custom one either upgrade to an lsd
 

Yakozan

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How long do you go full out on the track before this happens?
I could easily do like 30min in a row on a track without any diff problems on a stock diff. My biggest issues was overheated tyres and fear of cooking the brakes (never did though). Never experienced any diff problems.
 
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How long do you go full out on the track before this happens?
~ 20 minutes

It was the same on the Oschersleben Track 2 weeks ago and last wednesday in Anneau du Rhin.

First stin is ok, but once the car is hot, some oil blows out.
At Anneau I did 78 flying laps! Which is nearly 230 km under race conditions, outside temp was 25°C.
Yesterday I refilled maybe ~ 150 or 200 ml of oil.
That might be more temperature stable.

I should try oil for race purpose, like the Motul Gear FF, which is W140.
 
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S14 has a viscous diff.
As the wheels turn at different speeds the fluid inside heats up and becomes more viscous. As viscousity increases it provides resistance between the wheels and if they keep turning at different speeds the temperature hence viscousity increases until the diff locks solid.
Once you are driving down a straight the wheels are moving at the same speed so the fluid would cool down and the diff would unlock.
If there was no cooler fitted and you drove fast road/track there would be little chance for the fluid to cool down so your diff would become locked solid most of the time.

BTW if you change the diff oil to a different type/grade you will change the operation of the diff. I'm not a diff expert but I would image going to a thiner grade will reduce the locking effect of a torsen diff and increase oil temperatures while going thicker would do the opersite. Any diff experts on the forum?

Wikipedia has a good article on different types of diffs:
http://en.wikipedia.org/wiki/Limited_slip_differential
 
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