Hey everyone,

My name is Mike and I'm the proud new owner of a 1990 300ZX NA. Super clean car. 62k original miles. I think I got a great car.

My goal is to build the car for SCCA STX class. I don't know if any of you know the rules in regards to building a car for STX solo competition... but I'm completely sure that you know a lot more about suspension setup and wheel fitment than I do.

The car I bought is BONE STOCK. My focus is suspension and wheels first... power can wait... and I have absolutely no idea what to do there... we'll see.

What are the things I should look for immediately as far as common failures... etc? I'm going to change the timing belt asap... because I don't think it was ever done. What else should I look for?

I'm going to post pictures soon and track the build on these forums. This should be interesting. As far as I know... this will be the first 300zx in national SCCA competition!

I have a couple of major questions right off the bat.

1. I want to run 17x9" Wheels on all four corners with 255 width tires. I don't mind using spacers. That being said, is that even possible? I can't find a lot of info on that. What offsets might work? I really need to be able to run 255's. I'm shooting for -3.2 negative front camber. Will that make a difference? I read somewhere that 17x9 +24 fit... but will they fit 255's? **EDIT** Just found a post saying that 17x9 +35 should work all the way around.. however, doesn't mention camber.

2. What coilovers would you recommended? I"m thinking kw V3's...

3. I can only do one form of camber adjustment front and rear. What would you recommend I do to allow the fitment of the wheels (17x9 and 255 width)? I was thinking upper on front. However, I'd want to do whatever I needed to in the rear to reduce weight. My understanding is that both top and bottom arms can be adjustable and adjust camber. I need to be able to modulate toe as well...

4. Sway bars? I'm willing to test whatever.. but it would be nice to have a base line. The car needs to be able to rotate at lower speeds than what most would be used to on a road track... it's autocross.

Thanks in advance for any insight or help anyone can provide!

Sincerely,
-Mike C.
Salt Lake City, UT.

w00t! Another Utah Z'er! Welcome to ZDriver.

We have a local Z club (Z Car Club of Utah), but I think their website is down. Hit them up on FB: https://www.facebook.com/groups/337432754575/

JSpendlove and a few other people know quite a bit about modifying and auto-xing the Z32.

Yeah, it is down... Thanks for the info! Is JSpendlove local? I hope some people will chime in... tires / wheels more than anything.

I'm running 265/35/18 all the way around on my 90 tt. 255 should fit.




I need to post an intro

Offsets? Fenders rolled or pulled as well?

Don't forget the camber can make as much a difference as wheel offsets.
I'm running 245/40, 9" x 17" +25mm in the front, about -1.5° camber -- fits with a good amount of space.
In back I've got 265/40, 9.5" x 17" +35mm, about -2.5° camber -- really close fit on the outside but no sign of rubbing.
The car's lowered close to an inch, and I haven't rolled or pulled the fenders. If I was at stock height with that amount of camber I imagine I'd have plenty of room.
Hope that helps some!

I will look up the offset when I get home from work. Fenders aren't rolled or pulled as far as I know.

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The offset on my rims is 38mm all the way around. 18x8.5 rims.

And per the above post: Changing springs changes class as well. If he's going to swap springs and shocks and can afford it he might as well go with the coilovers.

Of course it's usually best to run a season or two with the car as is and make the nut behind the wheel tighter before throwing a bunch of mods at the car. If one is a novice to racing that is.

Thanks for the feedback. I've been racing for about 5 years now. Multiple National Tour / Pro wins... Etc.

I want to build this car ASAP. Coilovers are perfectly fine in STX. What I seem to be running into more than anything else is solid spherical bushing in the upper and lower suspension arm parts. These are not allowed. I can do urethane, but the ratio of metal to rubber can't change. I need at a minimum -3.2 camber in the front and -2.2 in the rear. What's the best way to accomplish this?

Camber plates don't get you enough range of adjustment?

Ummm are we talking about the same car? This is a multi-link. There is not a camber plate option.

There is actually, bur it's more for getting your coilovers out of the way of fat *** tires. I guess it could change the way the suspension acts as well if it was tilted in further.