Tried different diff fluids to change its behavior?

j-rho

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I know, I know, get a Quaife...unfortunately where I race we have to run the stock diff. Will actually be taking the Quaife out to put the stocker back in.

Wondering if anybody has experimented with different types of fluids or levels of LSD additive to change the behavior of the stock Hydro-Lok unit. While my situation is autocross specifically, track-based experience with R tires in second gear corners is perfectly applicable.

I would anticipate a thicker fluid with less LSD additive would provide quicker/stronger "pump action" to the clutch plates. This, at the price of extra understeer in the form of rear axle lockup in tight low speed corners, and a delayed "release" once the pack is locked together. Conversely a thinner fluid would see less mid-corner push, at the expense of more corner-exit inside wheelspin.

In autocross some cars roll so much they go beyond the power-balancing ability of the Quaife and still spin the inside rear. My car hasn't been doing that so far, so I'm hopeful it will continue to work well with the stock diff regardless of the fluid used.

Any experience from those here would be greatly appreciated as I get ready to swap the stocker in...thanks!!

Jason
 
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j-rho

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C'mon, anybody? :( Would really be interested in people's experiences here. Anybody do a fluid change and forget to put in friction modifier?

Any gotchas on doing a fluid change on an '04 SRT-10?
 

VIPER R

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Try jeep and 4-wheel forums, I think they may modify these more than Vipers
 
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I have used both in Solo and the fluid will change to some extent but it will also chew it up faster. The clutches need the modifier and fluid for longevity. The thing I do is brake early and then "load" the diff sooner to get it working in a straighter line before entering the corner. It will stay more hooked upi and not produce the push you experiance.

99ESP Cobra
 

Canyon707

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I know, I know, get a Quaife...unfortunately where I race we have to run the stock diff. Will actually be taking the Quaife out to put the stocker back in.

Wondering if anybody has experimented with different types of fluids or levels of LSD additive to change the behavior of the stock Hydro-Lok unit. While my situation is autocross specifically, track-based experience with R tires in second gear corners is perfectly applicable.

I would anticipate a thicker fluid with less LSD additive would provide quicker/stronger "pump action" to the clutch plates. This, at the price of extra understeer in the form of rear axle lockup in tight low speed corners, and a delayed "release" once the pack is locked together. Conversely a thinner fluid would see less mid-corner push, at the expense of more corner-exit inside wheelspin.

In autocross some cars roll so much they go beyond the power-balancing ability of the Quaife and still spin the inside rear. My car hasn't been doing that so far, so I'm hopeful it will continue to work well with the stock diff regardless of the fluid used.

Any experience from those here would be greatly appreciated as I get ready to swap the stocker in...thanks!!

Jason
Are you interested in selling this diff? I have some complete diffs in my garage maybe we can work out something if your interested.
 
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j-rho

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Switched to J-Rho's Diff Cocktail 2.0, seems to lockup a bit better on the street, will see how it works this weekend. It's a 2-day race so if Saturday is not going well, can switch to version 3.0 for Sunday.

The racing diff that was in the car belongs to the car's original owner, and since he's got 2-3 Vipers still, I think he wants to keep it.
 

Racer Robbie

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C'mon, anybody? :( Would really be interested in people's experiences here. Anybody do a fluid change and forget to put in friction modifier?

Any gotchas on doing a fluid change on an '04 SRT-10?

I have been running the following in my 2003 without any friction modifier as Royal Purple told me it was not necessary. 20,000 miles and still going strong.

ROYAL PURPLE
01301, 75W140, MAX-GEAR
 
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j-rho

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Hi Rob,
I looked at that fluid, Royal Purple makes great stuff. Unfortunately (for me) it contains limited slip additive already mixed in, as do a lot/most of the better gear/diff fluids. I'm moving towards fluids that don't have any of the frictoin modifier, or fluids specifically designed to slipping clutches.
 
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