The Official 370Z Autocross Thread

[AutoX Z]

Well the BS/CS merger is official. Looks like we've got to beat the MSR's and ZOK's now.

[Ruff]

Originally Posted by AutoX Z

Well the BS/CS merger is official. Looks like we've got to beat the MSR's and ZOK's now.

Well recommended to the BOD, but that usually means its a go.

I really don't think the MSR's and non-turbo ZOK's will be a prob, goodluck against the Porsche Boxter...

[AutoX Z]

Originally Posted by Ruff

Well recommended to the BOD, but that usually means its a go.

I really don't think the MSR's and non-turbo ZOK's will be a prob, goodluck against the Porsche Boxter...

There's an S that runs locally with mid pack national talent on hoosiers that I am right with at the moment in a completely showroom stock car. I don't think the non-S will be that much of a problem.

Now who wants to buy my tires?

[theDreamer]

AutoX Z, let me know when/where you are going to Autocross next, I might come out for some Z support and watch/learn for later.

[pgrmstr]

http://scca.com/documents/Fastrack/0...strack-nov.pdf

Looks like its official....CS for 2010

While the 370z is not specifically mentioned, it was classed under the 350z line item so does indeed move to CS for next year.

[Ruff]

Originally Posted by AutoX Z

There's an S that runs locally with mid pack national talent on hoosiers that I am right with at the moment in a completely showroom stock car. I don't think the non-S will be that much of a problem.

Now who wants to buy my tires?

If that's the case, the 370 might really be an overdog. Hopefully SCCA will let it stay...

[AutoX Z]

So I'm getting everything in order to go ahead and start prepping my car for next season.

At this point I don't think I'm going to have enough money for new dampers but I also don't think there are any quality solutions at the moment so I'm ok waiting on that.

I'm just going to get an extra set of sport rims, nismos are too expensive/hard to find and not worth it for a couple pound savings per rim on a car with this much power.

For Hoosiers I'm looking at the 265/35/19 for the front and 295/30/19. Both are a bit smaller in diameter than stock but its the only options at the moment so hopefully it won't have too great of an effect on the gearing which is about perfect right now for autox. I'll crunch the numbers later to see how much top end I'm losing but like I said its the only option so it doesn't really matter right now.

Which brings us to the swaybar. This is where I need some help from yall picking the right one. My feel of the car is that it flops around like crazy in quick transitions and the steady state balance is understeer. I know alot of the behavior in transitions is better fixed with improved damping but again probably out of the picture for this year so how big of a bar would you recommend without making the steady-state balance even worse. I know in theory a big bar can help reduce understeer in camber-challenged cars such as ours but traditional knowledge also says that in general the stiffer front end will reduce front end grip, so where's the balance? Any input/experience on this would be greatly appreciated.

I want to show what the 370 is capable of, I may not be the perfect driver for the job, but I know the car can win so please help me out.

[Ruff]

Run 295's square...seriously...

And I'd run as big as bar is available on the market, it will help put the power down.

I'd be suprised if the car can get it done without shocks, the 350z sure as hell can't...

[ChrisSlicks]

I installed the Hotchkis sway bars, full set. The car was dramatically better in transitions, however it made the low and mid speed understeer much worse. I can only imagine that it would be worse still without the rear bar. I corrected the understeer by adding front camber using the SPC replacement upper arms. I'm going to build the car up for BSP as I want to focus on track as much as Auto-X.

[Ruff]

Originally Posted by ChrisSlicks

I installed the Hotchkis sway bars, full set. The car was dramatically better in transitions, however it made the low and mid speed understeer much worse. I can only imagine that it would be worse still without the rear bar. I corrected the understeer by adding front camber using the SPC replacement upper arms. I'm going to build the car up for BSP as I want to focus on track as much as Auto-X.

What size tires were you running front and rear?

The reason I say go square is will help with the low speed understeer, even with the bigger front bar.

For stock class, I really don't think the car can get it done without shocks. But regardless, run a big front bar and a square tire setup.

[ChrisSlicks]

Originally Posted by Ruff

What size tires were you running front and rear?

The reason I say go square is will help with the low speed understeer, even with the bigger front bar.

For stock class, I really don't think the car can get it done without shocks. But regardless, run a big front bar and a square tire setup.

I'm running 275 front 305 rear. Didn't really want the 305 rear but it was the best fit diameter wise. I think the front is pretty much maxed out for the stock size rims. Hoosiers would help but I think you'll be cording them pretty quickly with the stock alignment.

The stock shocks actually seem to work pretty well in conjunction with the uprated sway bars, although probably not quite as well in stock class as you are stuck with the stock rear sway bar.

[Ruff]

Originally Posted by ChrisSlicks

I'm running 275 front 305 rear. Didn't really want the 305 rear but it was the best fit diameter wise. I think the front is pretty much maxed out for the stock size rims. Hoosiers would help but I think you'll be cording them pretty quickly with the stock alignment.

The stock shocks actually seem to work pretty well in conjunction with the uprated sway bars, although probably not quite as well in stock class as you are stuck with the stock rear sway bar.

That's your problem right there with the low speed understeer. And no way in hell are you maxed out on 275s on stock wheels, we run 295 hoosiers on the stock 18x8 350z wheels with no problems, and by far the quickest setup with the car being super neutral. Unless you are talking street tires that are dual purpose. Then you're on your own and the car will kinda suck at autoxing. Until you got to a square setup, you'll going to have tons of understeer auto-xing a Z. And with that much rubber up front, even with stock alignements, they last quiet a while.

[pgrmstr]

So any news on the shock development front?

I emailed Lee@koni but have not heard back from him about any progress. I also email Vorshlag concerning the possible AST strut...and Terry is needing a pair of stock fronts for measurements....so it doens't sound like much movement there. I have thought about pulling my fronts off and shipping them to him as my car is stored for the winter...but I need to call him and discuss what the plan is with AST....SA or DA and what kind of cost. I'm not wanting to spend $2k+ for a SA...but if its a DA, then I would likely pull the trigger.

The other thought I had was going with the Nismo struts. I know they aren't adjustable, and not sure if they'd be legal....I assume the ride height difference is done with the spring, not the strut....but assuming they are legal, and you can find a inexpensive take off set....do you think they'd be worth do the job for the 370?

[ChrisSlicks]

Originally Posted by pgrmstr

The other thought I had was going with the Nismo struts. I know they aren't adjustable, and not sure if they'd be legal....I assume the ride height difference is done with the spring, not the strut....but assuming they are legal, and you can find a inexpensive take off set....do you think they'd be worth do the job for the 370?

The Nismo spring is only about 10% stiffer, but the strut has about 80% more damping so yes I would say it would be a big improvement. I can't see any reason why it wouldn't be 100% legal, you can pretty much run any stock type dampers you want.

[AutoX Z]

Originally Posted by ChrisSlicks

The Nismo spring is only about 10% stiffer, but the strut has about 80% more damping so yes I would say it would be a big improvement. I can't see any reason why it wouldn't be 100% legal, you can pretty much run any stock type dampers you want.

The issue would be the spring perch location. If the nismo is lowered by some combination of changing spring perch height then the nismo struts would not be legal.