240Z setup questions for Mr. Katman

[ITS_Racer1]

KT,
Following the advice in your previous dissertation on setting up the 240Z, I plan to switch from "west coast" setup to "east coast" (see specifics below). Two questions
please:

1) By the text book, this should tighten up the car. Is this the effect I should expect on the 'Z?

2) After going to the quaife LSD from welded, I get significant inside wheel spin on some corners. Is the solution to go to some kind of tender spring to keep more down force on the inside wheel when the body rolls? Other suggestions?

Thanks, Todd

Current setup:
Ft: 330lbs/in R: 380lbs/in
F sway bar = 1 1/8" R sway bar = 3/4"

Target setup:
Ft: 375lbs/in R: 325lbs/in
F sway bar = 1 1/8" R sway bar = 3/4"

[kthomas]

1) paraphrased: "That's the great thing about the 707 son, it can't read the book!" - George Kennedy from the movie "Airport". I have found that the front/rear balance on the Z wrt spring rates is very sensitive to roll center, which is very sensitive to ride height in the front. So, YMMV.

2) We quickly weaned ourselves off the sway bar in back. On smooth tracks, I'm not a big fan of sway bars at all, I just use them for trim. Though hollow, our front bar was the equivalent of about a 15/16 diameter solid, with poly bushings on one end of the end links for stiffness adjustment, so overall not a lot of roll control via sway bars. I'd ditch the rear bar, they tend to pick up the opposite wheel.

At those spring rates you have just enough spring compression to account for the amount of rebound travel you usually need (2+ inches). I always managed to engineer the shock location such that I didn't need helper springs at full droop, but if you have that situation you need them anyway to make sure the spring reseats properly.

We ran a clutch type limited slip and basically treat the throttle as an on/off switch and never had any wheel spin down to 45mph corners (second gear with a 3.90 diff).

Give the rear some more compliance (ditch the bar) and then work on making the front stick.

I'll be out of country for a week so I'll answer any further questions when I get back.

Best of luck.

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katman