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Anyone have this upgrade? what does it entail and any negative effects by going with this mod? Sure sounds convincing, but I am a n00b

 

Interesting . . .

 

Just sounds like putting in a better clutch type diff. in a RWD car. It does just what the description says. It will help the car oversteer where it used to understeer. The only down side is it will make the rear end easier to break out, so you'll just have to be careful when pushing the car harder.

 

I have this. It works as advertised. Accellerating out of tight corners it helps keep the inside rear tire from spinning. On our car that is set up with high spring rates and extremely sticky tires we had to make some adjustments to loosen the rear up again as adding the rear diff made it TOO tight.

EVOlutionary

 

Thank you for the insight. Has Ripple been provided this feedback? I wonder if he can offer more clutch options, perhaps?

 

sounds like this is more what I need instead of a rear sway bar. After switching to race tires I started to notice all of the downside of the stock rear end on tight turns.

does anybody else use this / make upgrades?

 

Tight where? Corner entry, mid corner, steady state?

I am assuming it aided in corner exit rotation to some degree.

This is actually on my list for winter upgrades.

 

I assumed that it helped with exit and rotation as well. MOre info would be greatly beneficial. I plan on dropping the diff as well and would like to get this done, if possible!

 

I use this in my roadrace car, the car rotates mid corner and exit better than it did before. It makes the rear a bit looser but who doesnt think that is a good thing in an Evo?
Marty

 

I think Daddio did this mod and his car drives like a rear drive car. Wish we could do this in STU.

 

Marty - this is KC from the gvr4 boards. Nice to hear from you, man!

Well, I guess this could reduce the need for an oversized 27mm rear swaybar or extremely stiff springs, perhaps? Iam begining to think its worth it!

 

Very interesting. I was previously looking towards the GSC 60/40 center diff to get some better rotation off the corner, but this looks as though it may be a more cost effective first step!

 

I thought you already had this upgrade. You mean you sprung for the GSC 60/40 center diff before going with this much less expensive mod?

My friend Eric just got his rear diff back from TRE and mine is on the way there today. I'll post a summary of what it feels like when it's back in the car. My primary reason for wanting this is to reduce or eliminate inside rear-wheel spin on corner exit. As it is now, I can't put power down until my inside wheel drops back down onto the pavement, which costs me a good fraction of a second out of each corner. I was also thinking of going back to the softer stock rear sway-bar, to keep the inside wheel on the ground, but I'm afraid that may cause understeer.

By the way, you may want to consider doing your own shipping, rather than having Jon arrange it with FedEx (he'll do that for $100 round-trip). I had my diff out last Thursday, and he didn't have FedEx pick it up until this Thursday. Meanwhile, the garage is *****ing about my car taking up space, and I'm paying $25/day for a rental car.

That being said, Jon is a great guy, and really interesting to talk to -- he really knows his stuff when it comes to the drive-line and how it affects handling.

 

I guess I just don't understand how this would help. Seems as if a stiffer clutch pack would make the car either want to stay straight or break traction and drift. If we want the rear to steer better wouldn't we want a torque biasing rear like a quaife?

 

Remember, I said my inside rear wheel is completely off the ground in steady state cornering. It takes probably a half-second to set back down when I throttle out of a corner. My understanding of helical diffs like the Quaife is that they don't work if one wheel is completely air-borne. They act like an open diff in that case. (Someone correct me if I'm wrong, please.)

The goal for me in rebuilding the diff is simply to be able to put power down on corner exit. If I can also steer the car with the throttle in turns (like a RWD car), then that's just icing on the cake, but not as important as being able to accelerate out of a turn!

And by the way, I'm not the only competitive autocross Evo that lifts an inside wheel in cornering. Once you go stiff enough for top-autocross times, you don't have much droop available.

At the Devens national tour event last season, I saw Daddio switch to a smaller rear sway bar between the morning and afternoon runs (yes, he did the job by himself!). It appeared to be the stock sway bar. I may go back to that myself.