Autocross questions

cossie1600

Personally I would do at least 255 in the F&R

KevinB

So what size tires for stock 18 inch rims front/rear (ie. touring nonsport) would you guys rec for autocross? I'm not sure what options are available that would be reliable and allow me to have a better selection of tires.

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09 6MT MB: Int/Ext LEDs, Stillen G3 + FI test pipes + FI cat back + Stillen sways + Clutch Helper Spring

Shamu

Curious what you are basing this on? I have been driving prepared cars etc for a long time and well setup 370z on staggered setup is completely nueteral from what I have seen. I experience very little understeer with 295/315 stagger. I think for average ax driver staggered will work fine if you have flexibility to use differnt suspension setup than stock.

I don't think shoving a 315 under front is going to accomplish much and for people in cooler regions I'd argue solo driver will have issues with getting that much tire warm.

I will be experimenting however I don't think a well setup car on mild 295/315 stagger will see as much understeer as you think. If anything my car tends to have a little oversteer. But I base this from running mostly cool venues as a single driver. Just wish more serious ax guys were trying SP/SSM mods.

A two driver car on warm surface may in fact benefit from 315 upfront. But honestly if I go to 315 front I'm going to 335 rear.

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Grant

Shamu

sCCA just announced a road tire class for stock cars that will happen at National tour events. All rear wheel drive cars will run in an indexed class. Given 370z is CS you would have favorable pax. This might be perfect timing for you. Just need to find good street tires that fit your wheels. Not sure what tire would be best?

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Grant

KevinB

Shamu,

I am thinking of going with 245/45/18 up front and 275/40/18 (base, stock 18" rims). This will keep a staggered setup with bigger tires than I have right now.

For tires, I am considering trying the Continental Extreme Contact DW. They have gotten some good reviews:
http://www.modified.com/tech/modp-09...s/viewall.html

And they are about $800 for four corners (including shipping).

Since this is my first foray into autocross I don't have the skills to push the car hard enough to make (in my opinion) a big enough difference that I would need to go with a much more expensive tire.

In regards to sway bar settings ... I have stillens up front and rear ... any suggestions regarding stiffness front vs. rear?

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09 6MT MB: Int/Ext LEDs, Stillen G3 + FI test pipes + FI cat back + Stillen sways + Clutch Helper Spring

IMWEZL

I think the conti extreme contact DWs will be okay. I have them on my MKV GTI and they put up pretty good with my very spirited driving style. They progressively give out but that might change on a RWD setup.

Next weekend is the first event in my area. I signed up for the novice day just to get some more seat time.

Is everyone just using vinyl for numbers? I really don't want to use blue tape. :/

cossie1600

You really have no tire options in your size short of the RE-11, which are way overpriced at $310+. The only thing you might want to think about doing is to go with a smaller size, Kumho XS can be had for about $800 if you are willing to run a smaller tire.

Shamu

245 won't be enough front tire for autocross.

I'd reccomend Hankook RS3 in 265/35/18 front and 275/35/18 rear or even 275/35/18 front and 285/35/18 rear. Hard for me to say what will work on your car in bar department as I don't know what else you have but 370 needs lots of anti roll especially with stockish camber settings so I'd start with at least mid settings and then experiment.

If someone were to hear my setup they'd say no way would it work for ax. I have huge 35mm front bar and 1000 lb front springs with stock nismo rear bar and 450 lb rears. I spent lots of time on camber and toe settings but you can't do much about camber in a stock car.

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Grant

IMWEZL

Is the 370Z still CS for stock classes? My local region told me I was BS. I ran against a Subaru WRX STI that put up one heck of a fight throughout the day and edged me out.

Going by the 2011 classification list it states the Z as CS.

Also any tips on psi settings for the RE-11s? I chewed the fronts up a good bit on the course we ran but then again that was more than 15 runs on a 25-30 second course.

///MSH

I just went to 18's... I am committed to ASP. I have 18x9.5 +30 (f) and 18x10.5 +15(r) with hoosier A6's 275's up front and 315's in the rear. This is an interim for spring (less heat in tires) until summer where I will bump up to 295's in the front. I'm with Shamu...you need a bit more tire in the rear despit the desire to be square.

To the point of this post and thread....other than seat time....tires,tires, tires. I figure A6's are good for 1.5 -2.0 seconds on a 45-60 second course.

Who will I see at Nationals this year....I will be there in ASP. side note - get a co-driver.....it's a great mod and it does help the budget!!!!!!!!

03threefiftyz

I'll be there in BSP.

AutoX Z

I'll be in CS.

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2013 SCCA Solo National Champion
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IMWEZL

I'll try to get there in CS.

trickle80

base model 2009

autocrossed twice now, basically everytime i come out of the corner and get on the throttle i start sliding out. I am wondering if this has more to do with my inexperienced heavy foot, the lack of lsd, or the stock tires.

takjak2

all of the above

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