The Official 370Z Autocross Thread

[handyman]

I just put 285 RE-11's on all 4 corners. First impression from street driving: definitely a lot more balanced. Throttle induces oversteer more easily (maybe even too easy). Turn in is a bit vague, steering is heavier, and the front end feels more planted (all likely due to the larger front tires). The 285's are bulged just a bit on the front wheels and stretched just a bit on the back wheels, not a bad fitment at all. I'll give more details once I've broken them in and stretched their legs around some cones.

[jaxxx]

You ran 285 on all 4 wheels.?

[cossie1600]

yup, they are light years ahead of my old 265/285 setup

285 all around this year
YouTube - 0511 370z autox

265/285 last year
YouTube - Tom driving the 370z

Hitch will be here tomorrow, hope to get my friend to help me install it on Saturday. Anyone have an extra parking space for my trailer in NY?

[handyman]

Yea, they actually fit pretty well. A bunch of the local autox guys were trying to convince me to go as far as 295 on all 4. I didn't want to push it, but after seeing the 285 fitment I definitely believe its doable.

[cossie1600]

for dedicated race tires, i dont see why not. i just dont want to go that far for street tires

[AutoX Z]

I'll repeat what I told you before. Street tires do not respond to being squeezed onto rims the same way that R-comps do. In general you will get optimal grip with a street tire if it is square or slightly stretched on the rim.

[cossie1600]

thats why i have 285, a slight pinch in the front to get the balance i need. i am not some ricer trying to jam 305s on my rim to look cool

[handyman]

Originally Posted by AutoX Z

I'll repeat what I told you before. Street tires do not respond to being squeezed onto rims the same way that R-comps do. In general you will get optimal grip with a street tire if it is square or slightly stretched on the rim.

I totally agree, I was just surprised at how well the 285's fit. I expected them to be more of a squeeze.

[cossie1600]

Originally Posted by boardkat

well, that was a well timed question then! VERY interested to hear about how your install goes!! please report back, and take pics if it isn't intuitive or if you have to take the fascia off, etc.

I used 11483, it doesnt really fit well without heavy modification. You can use it if you don't mind cutting the rear bumper

[boardkat]

Originally Posted by cossie1600

I used 11483, it doesnt really fit well without heavy modification. You can use it if you don't mind cutting the rear bumper

uggh, was hoping to escape any bumper modification. any reason you chose 11483 over 11493?

[cossie1600]

you are going to need modification regardless of which one, so just go custom

[Belsavis]

Originally Posted by cossie1600

yup, they are light years ahead of my old 265/285 setup

285 all around this year
YouTube - 0511 370z autox

Wow, suddenly i feel like i shouldn't complain about a 45s course...

[handyman]

Had two autox's this weekend. Won the stock street tire class and placed top 10 pax in both. Still getting inside rear tire spin up on sweepers, and still fighting understeer (although its much better than before). Hopefully an alignment and front bar will help. Also, I still have a lot to improve with my driving, I'm definitely not as smooth as I could be and I'm not using trailbraking/weight transfer to my advantage enough, which would also help.

Thoughts on the RE-11's:
1. They love pressure! I started with 40f/35r and they sucked. I ended up with 47f/45r and was still rolling the fronts over a bit further than I would have liked. The higher pressure also helped a LOT with the numbness I previously felt on the street. The pressure in the rear didn't seem to have much effect, From 38 to 45 there wasn't much of a difference other than feeling slightly more crisp (times where the same)

2. They kick *** in the wet. On Saturday I was leading pax in the pouring rain in the morning, only to drop back to 10th once it dried out.

3. Good feedback. I could easily feel/hear understeer and the oversteer was nice and progressive*, which allowed for easy modulation.

*The only issue I had was once on a wet lap the back end completely let go without any warning. I may have hit a puddle or slick spot on the course, but it was very unnerving. Luckily it didn't happen again, so I'm chalking it up as a fluke.

Video of the winning lap today
Video of a very sloppy wet lap yesterday

[ChrisSlicks]

Those are some crazy high pressures, I never found it necessary to run them that high.

[handyman]

Thats what I thought too, but I was still rolling them over about halfway down the triangle which is already very low on the sidewall. Its worth noting that this was on a very grippy lot with stock camber.

I think I'm going to go ahead and order a pyrometer to help sort them out. The engineer in me needs more data