Buub

iTrader: (1)

Likewise, my experience with my old '86 CRX Si (well it was new at the time) was widening the wheel while maintaining tire size helped handling a lot. Hence, it seems logical to me that putting a tire that is too wide for the wheel will actually hurt performance since it won't get a good flat contact patch.

Blue Liquid

The thing is, it's going to be difficult to really say whether or not there is any negative effect on ABS unless some before and after 60-0 stops are performed. Just putting on the same stagger and driving on track or street, well, I can't imagine it would be overly noticeable, but in reality it may be taking 10 feet more to stop, or someting to that effect. This shoud be tested by someone who has the even stagger...

raceboy

Just my 2 cents. I think that tire combo is fine for autoX and I don't think you would really run into a safety issue on a road course, but I do think that you are gonna kill the outside edges of the front tires on a roadcourse unless you have some way to dial in more front negative camber. By going that wide up front, you are giving up tons of sidewall stiffness by the sidewall not being vertical.

I have this problem on my Z with my RA-1's up front. I am looking at as many front camber adjustment solutions as possible right now. Probably going to go with Downshift's inner noconcentric bushings. As it is, I have to run 2lbs more air in the front tires and I have to swap the tires on the rims after every two days of driving. The fronts seem like they will be good for 6 to maybe 8 days max of roadcourse work. The backs look like they will wear like iron.

2003z

iTrader: (7)

I rotate my race tires around all 4 corners and have noticed the outsides are worn much more than the fronts also. I guess thats from having them on the front?

I'm gonna have them swapped around on the rims after the next run. I think Sams club should be an inexpensive place to have this done, but only if you have 17s or smaller, since they can't do 18s (at least around here)

Buub

iTrader: (1)

Your race tires aren't unidirectional like the street tires?

raceboy

Directionality makes no difference unless you are in the wet. There is a great article in this months Grassrootsmotorsports about directional tires, when they mounted them backwards, there was NO loss in the dry, but stranger yet, there was NO loss in the wet either. Seems like a scam to keep people from rotating their tires and wearing them out quicker.

A lot of people mount Hoosiers backward because of where the radial grooves fall and they actually work better.

2003z

iTrader: (7)

kuhmo victoracers arent directional

D'oh

Hey, lot's of good comments

I went out for a "sprited" drive this afternoon (up HWY 9 to Skyline and back, and then up Bear Creek to Skyline and back) and noticed a couple things.

1. I ran with VDC/TCS ON, and not once did either one engage. I was actually pretty surprised at this, since I expected the VDC at least to activate. I got up to some decent highway speeds, and ... nothing. Therefore, I would not worry too much about that aspect. I may need to do a run at the AutoX with VDC ON just to see if it still engages, but at this point, I'm not concerned with this as a problem.

2. As far as ABS goes, I never had a chance to test the ABS with the race tires, but most systems actually need to sense a full lockup before the system will activate. The Z's system may be more sensitive, but it would be very unlikely that the ABS system would be noticeably affected by the similar tire sizes, since it looks at each wheel indepently (although I guess it does compare them to something to determine if the car is moving - maybe the driveline?). I mean, if the VDC system didn't get confused, then the ABS would be even less likely to be affected. Again, I may be testing this next weekend.

3. I definitely noticed tire wear on the outside edges of the front tire. The middle of the front and all of the rear tires looked unused after my 55 mile trip, but the outside of the fronts had definite scruffing. I was able to rub off some of the srubbed rubber with my finger. It was nothing serious, but at the same time I was not cornering too hard on this initial run. I think adding some pressure to the fronts will be required. They were at 34 PSI cold. I'll probably pump them up to 38 or so before a race.

4. The V700's are "directional" (although as raceboy noted it really doesn't matter unless there is standing water) but the tread does not go all the way across the tire, so after a couple laps they will probably be like slicks and the direction won't matter, even when driving through lakes.

5. I saw Kevin (but didn't get to meet him) at the only SCCA AutoX I've been to so far (the one at the Marina airport a couple months ago). He has definitely shown the Z is capable, so I hope I will be able to stay close with my new tires. His exhaust is damn loud too, BTW.

6. I had to remove the screw and spacer on the front brake rotor in order to get my wheels to fit correctly. Did anyone else need to do this with aftermarket wheels? I'm guessing that screw was simply to help pop the rotor off the wheel spindle when it needs replacement, but if you guys have any ideas on what it's for, feel free to chime in.

Later,
D'oh!

2003z

iTrader: (7)

the screw is to keep the factory rear wheels off of the front when a stupid mechanic tries to rotate the tires. Interesting that you had to remove it though, as I took my wife's g35 to the track and forgot to remove the bolt, but my rpo-2j's fit over it fine.