240Z Quaife woes...

Just replaced my welded diff with a Quaife ATB unit on my ITS240Z. Last weekend at Sears Point I experienced extreme wheel spin on the inside drive wheel. I was leaving 50ft strips of rubber out of T2.

Quaife support suggested I am lifting the wheel off the ground (ATB needs some resistance to work) and I need to soften my suspension to get this working. Have others seen the same problem?

My setup....west-coast setup...:-)
Front: 325lb springs, Tokico illumina set to 5, "Big" sway bar (I need to measure)
Rear: 380lb springs, Tokico illumina set to 5, "micro" sway bar.

Any thoughts?
Todd

A couple of things I would try:

1. Try softening the rebound on the front shocks to allow the weight to transfer from the front to the back sooner. Go to a smaller number on the front shocks (try "4" then "3").

2. Remove the rear bar and go to a slightly stiffer rear spring to compensate for the roll resistance of the rear sway bar. The rear bar will lift the inside rear wheel in a corner.

Each of those things should help reduce wheel spin.

MC

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Mark Coffin
#14 GP BSI Racing/Airborn Coatings/The Shop VW
Scirocco
Zephyr Race Coaching and Consulting
http://pages.prodigy.net/scirocco14gp

[This message has been edited by racer14itc (edited April 05, 2004).]

Todd,
This brings back old memories for me. I used to run an ITS 240Z at Sears for the PCRRC. Just a couple of things:

Most of the guys out here are running more front spring, and less rear spring. In fact, if you did a front to rear swap, that would be about right. When I ran Sears, we had the typical Ground Control setup with even lighter springs, but the rears stiffer than the front. With my work on a couple of fast Z cars at Road Atlanta, we found that the Tokico shocks aren't up to the task. They don't have enough valving with 250lb springs, much less 380 lb springs. I'm sure Jay at Ground Control could fix you up, or there are a number of other good shock sources out there, including Bilsteins.

We ran a Quaife out here in EP, and had a similar problem when the tire lifts off the ground. However, this is the way they are designed. Sears Point turn two is a tire lifter, so it would seem to either be off the power (slow), drive around the curb (ditto), much softer rear springs (may affect balance), or a different type of diff. I always liked the Quaife, so that wouldn't be the first thing I did. Another idea might be to remove the rear bar, if you're running a 1" front bar (rear is assumed to be 5/8"). That might let rear end work a bit more over that curb.

I know that doesn't solve the problem, but there might be a few things to try. Good luck.

Steve Spiers
#90 GT4 Nissan