mods, please don't move this to the wheel/tire section cause most of the stuff there is about appearance and what not...


background to the question:

i went to an autox today, and there were a couple sections where coming out of turns, i'd get on the gas (in second, if i had to guess, i'd say about 5k rpm) and i'd get massive spin, but i'd still be going straight, the car didn't oversteer out of control one bit. i didn't have to struggle to try and keep the rear end from coming around either. and it would spin for a pretty long time too, a good 4-5 sec's (i'm bad at estimating distances).

now on to the spin thing. it didn't really feel like you typical tire spin. i wanna say it almost felt like the clutch was slipping, then catching again (after a spinning for quite a while). but there was absolutely no clutch stink, and if it was slipping that bad, the stench would raise the dead. there wasn't the typical noise that you get when you're spinning a tire. i've spun these tires before, and i had the noise before, but not this time. i could faintly hear something from the rear spinning, but it was relatively quiet, and didn't sound anything like tire spin.

the autox was on an old airstrip that's also used as a drag strip, so there were some sections of vht on there, particularly right before the long straight on which i noticed this the most. it was a really fast layout, easily the fastest i've ever been on (thats right, a whole 6 or 7 events).

other info that may or may not be relevant. stock 07 18" wheels, 245/45r18 dunlop sportmaxx tires. hotchkis sways front and rear, powergrid endlinks on the front. front sway setting second from softest (out of 4 holes) and the rear in the middle (out of 3 wholes). power mods is only a catback, i made 282whp at a dynoday a week before.

so, is it possible to spin a wheel inside a tire during an autox? if possible, what do i do about it?

 

No.

 

If your car is not a base model without LSD then it's possible your LSD is worn out. They don't last forever. Might be time to upgrade the diff.

IF you have LSD, the rear tire should not spin separate from the other one. Mine has never spun a separate tire yet.

 

so then its just the inside tire spinning? damn viscous lsd...

 

^^ Most likely it sounds like it. So your LSD is probably worn out already. Try changing out the diff fluid if you haven't recently and see what happens.

 

i thought there was no way to change actual "viscous" fluid in the lsd, onlyh the lubricating fluid in the diff housing...

 

I am really not sure how the Diff works, but I was always told to change the fluid regularly to help the LSD out.

 

No, you're not spinning the wheel in the rim.

The viscous fluid inside the OEM Nissan LSD is sealed in place. The OEM VLSD in the 350Z can be easily overpowered and go open allowing the inside rear wheel to spin. You will have to learn better throttle control.

You can also adjust the suspension to help the VLSD work a little bit better. A bigger front anti-roll bar and smaller rear anti-roll bar helps.

 

^so you're saying that if i make my FSB one whole stiffer, it may help the situation?

that kinda sucks, cause i love how balanced my car feels (to me anyway) right now, since i added the sways. i'll try it out though, see how i like it...

thanks

 

The stock LSD being overpowered? I have never seen my car spin the inside wheel even when I have tried. That means only one thing and the LSD is starting to fail or it has already.

 

^i've spun the inside tire many times before, but never to this degree...

actually now that i think about it, its not really the inside tire, its always the right rear. i was pulling out of a driveway (wide empty road) on sat and i floored it in first during the turn, and the right rear was the outside, and thats the one that spun... the inside may have been spinning also, but not nearly as much as the outside...

 

+1 its a common occurrence on the stock LSD.

 

All I know is anytime I get on it in a turn, the rear of the car swings out and both are spinning. Never just one tire.

 

so just to make sure, it my lsd that went to sh*t? anybody have any different opinions?

 

Sounds like my open diff, before I got the Quaife.....

 

any sway bar setting's you suggest (what you liked when you still had the open diff). sways is the only adjustable thing i have right now, and its gonna be a while before i upgrade to a quaife...

 

Sorry but the Quaife was my first mod.

I have a Base model, so a limited-slip differential was at the top of my to-do list.

 

oh, i c, thanks

 

What you're trying to accomplish by moving roll stiffness forward (stiffer front ARB, soft rear ARB) is to keep more weight on the inside rear tire in a corner. Yes, the car will be less balanced but you might be able to turn faster lap times by getting more power down sooner in a corner. You will have to change your driving style to work with the new setup.

 

if i reduce roll stiffness in the rear, it will let the car roll more in the rear, therefore the inside of the car goes higher, therefore less weight on the inside tire.

or is there an error in my logic?

(not trying to sound like a smart ***, just trying to understand)