steve40th

I am on the fence now in regards to tires and shocks. I want both, but can only get one this year
QA1 single adjustable to replace my Z51 Bilsteins HD shocks (one autocross and very little actual miles on them, good shape just hard to drive on bumpy roads)
Or Tires, I am looking at Nitto RII for the front and Nitto DR 315's for rear ( to replace my hard as rock BFG KD's)
In your humble opinions, whats more important to you here in autocross.

TommyBoy72

Tires are the #1 mod in autox. Alignment is #2. Shocks are #3. This is in my opinion of course.

Lancer033

going from street tires, you're talking seconds off your time with the right tires and only tenths off your time for shocks. That said, i wouldn't go with put drag radials on the car. I'd stick with the RIIs all around if that what you're set on.

Diesel68

Tires are certainly the #1 item. I disagree with Lancer on the Nitto drag radials for autocross. I have used 315 drags on my C4 and Z06, and have been able to comfortably set local FTD with both using the drags along with some V710's mounted on the front. They have stiffer sidewalls than people give them credit. Just don't expect a lot from the RII's. They are not even close to V710's in performance, but they are certainly a great street/racing duty tire. I have autocrossed RII's and I found them to be only about a second quicker than my Kumho MX tires.

steve40th

Thanks guys. The tires are a compromise. They are stickier than BFG KD's and life expectancy here in Hawaii is due to weather/time not miles, so they will dry rot before they wear out. SO a short life expectancy for a tire is okay.
The Rears are 315 on my Vette now, as I committed to them with narrowing the rear and 275's would be in too far, unless I run the spacer on it. And I dont think the 275's will look good all the way around after having the 315's in the rear. And, for a street/track tire Kumhos arent an option as they are too sticky and will throw rocks more so when driving around. The Nittos are a compromise, but should do significantly better than the Hard BFG KDs that are dry rotted. My wifes Toyota and my Nissan have softer rubber than the KD's are now. And KD's are expensive right now.

astock165

Steve: what class & organization are you running with? If it's SCCA you will have to watch stock wheel size & offset packages to stay in stock, FWIW.

P.S. - my vote would definatly be for tires.

Canam

Just remember this friend. There are only 4 thinks between you and the track. The contact patch on your tires. Optimize these first and then move on.
BTW last year I swapped out my standard bilsteins for revalved very stiff shocks. Totally transformed the car with this mod alone. Good luck.

John Shiels

steve40th

They put me in BSP, which has some very wuick cars and very good drivers. Mostly prepped Datsun 240/260Z's

steve40th

So are you saying optimize getting these to stick via the suspension or get new tires?
My suspension is a ZO7 1991 sway bar set up, urethane bushings, Bilstein HD shocks, lowere, realigned via VB&P advanced street(mild , not very aggressive), camber brace and C5 brakes and FE1 springs.

AUTO_X_AL

If I had a choice between hoosiers and QA1's I would take hoosiers. In you situation I would do the qa1's over the Nitto's. I have seen some people fast on the nitto's but I think the shock upgrade will pay dividends. In BSP your going to need both to be the top dog but either way you cant lose. You will improve with either mod.

Al

steve40th

So you think the QA1'a will improve my car over what I have more than a new set of tires? I know the QA1'a are nice and can help allot with the adjustability making different driving situations more bearable.

Canam

Get the new tires first Steve, maximize them and your driving with them to the max, then look at spending money elsewhere.
The tires are your first significant investment

TommyBoy72

The big difference in SCCA from stock to SP classes is the unlimited wheel/tire options and potential weight savings. On the corvettes the extra power is minor (putting it down is the challenge) and the extra spring rates are going to knock of tenths like shocks, not full seconds like stickier tires can.

With that in mind, there are two thoughts with tires. All out best options (A6 or V710) or some compromise that makes you happy outside autocross as well. If you have your heart set on something and realize the potential drawbacks, I say go for it. Worse case, you burn them up and try something else next time.

steve40th

Tires seem the logical choice here. Fun factor will be higher, and maybe the less stiff tires will be less stiff on the ride as the BFG's are old and hard.

astock165

Oh what the hell ... since you're already in BSP just get a set of 11" ZR1s for all four corners with a set of 315 V710s and trailer them to the events!

You know you want too.

steve40th

Damn, I have been caught!!!!