Hah, so what you're saying is that you have saved 200lbs and your car looks better

I was imiagining that you hollowed out the interior of the car and took out the plastic. :P

 

i'd like to chime in. weight savings is BY FAR, the most important thing i've done (or undone depending on your perspective, hehe) to my g35.

stock wet, i was weighing in at close to 3550 without me in the car, keep in mind this is a 5 a/t, 2003 sedan, moonroof, leather, power everything, heated blah blah, everything except nav pretty much.

my current weight wet, is 3150, still with an auto tranny. everything about the car is better. acceleration, braking, handling, high-end acceleration, fuel-mileage (haha).

the Z is sort of heavy from the factory, but if you consider that a M3 weights 3400+ pounds, its not so bad. 2700-2800 wet is doable in a stock-bodied Z (except hood and hatch).

and about understeer, i'm driving a 245/255 setup with tein high techs (350z rates), and yes, the car does understeer. i have severely worse tire wear on the front compared to the rear after only 2 track days.

-phil

 

I just wanted to address the understeer thing more clearly. My car does not understeer at all unless you are over cooking a turn and generally driving poorly. You can make this car handle really well and still conform to solo-2 stock class rules. It is no secret how to set it up for stock class and most people go about it in the same way with minor tweaks hear and there. This is exactly how it is set up and it is really a pleasure to auto-x.

Alignment:
front: 1/8" toe out. Toe is the only thing you can adjust on the front.
rear: 1/4" toe in. -1.5 camber.
The toe out on the front is going to help your turn in alot. Toe in on the rear is going to make the car more stable and less easy to spin.

Tires: Do not run offset tires for Auto-x run 275s all the way around, the car needs this much tire, it actually probably needs more but I don't think you'd be able to fit it. Either kumho 710's or hoosier A3S05's (the A3S04 suck and wear out really fast.) The 275s in the front is going to completely change the way the car feels This alone goes 50% of the way to fixing the handling problems of the car.

Shocks:
Koni SA these are probably your cheapest option. They are good and I run them at full stiff all the time. The reason I don't adjust them is because full stiff still isn't stiff enough. But they do help the car transition alot better.

Front sway bar:
Hotchkis 40mm bar on full stiff. I'm sure everyone has there opinion on this, here is mine. You want the biggest bar you can possibly get your hands on. People will tell you it will increase understeer and it might if used on its own, but in conjunction with the other items listed above what it will do is 2 thing. When you are going through a turn the weight of the car on the outside wheel will cause it to lose camber, the FSB will help correct this and help you retain camber mid turn keeping more rubber on the ground. The other thing it does it make your shocks less independent causing weight to shift less, this will also make your car transition better.


When you start getting into coilovers and custom spring rate you start adding variables that can make your car slower. I suggest starting out with the alginment and working down the list above.

 

This thread has been both incredibly informative and inspirational, I'm going to have to find somewhere I can autocross now just to see how I can do/if it'd be something I might want to look into.

 

Well, here's my thoughts on the understeer issue. I have a '03 track that I have been auto-xing a little over two years. The race weight of my car is 3106 (it has most of the options) with 56% nose, most of the weight savings are in the back.

driving:
With that much nose weight if I try to trail-brake at all the car will understeer. Braking transfers too much weight to the front tires and overloads them. I find that if I get all my braking done before I turn in the car is much more neutral and will rotate predictably when the throttle is applied. Understeer isn't necessarily a result of poor driving, this car just wants to be driven differently than some others.

alignment:
The same as del105 except for the rear. I only run 1/8 in.

tires:
Matching tire sizes helps these cars a lot. With the amount of weight on the front end they need all the tire they can get, and I don't think stock they have enough HP to justify wider rear tires.

slow in....fast out

 

stock rear wheels are 8.5 wide right?

 

Yep. Track model and I think 35th anniversary....8in front 8.5in rear

 

I have the performance....so mine are 8.0 all around?

 

base, enthusiast, and touring auto. 17/7.5 f....17/8 r
touring manual and performance 18/8 f and r

 

OK, here's a question then. Since from what I have read in this thread, a wider wheel/tire in the rear will promote understeer. So, why would they have a stagger for the track model?

 

In my opinion:
A-appearance (probably the main reason)

B-If you go off the road forwards it's your fault. If you go off the road backwards it's the manufactuer's fault. LOL

 

The Touring Roadster 6-speed also has 17x7.5 F and 17 x 8 R. Chris said he was running 275/40s all the way around on his 17s. 275 on 7.5" rims sounds like too much tire, but I can't argue with his results.

 

Usually it's to prevent the rear from loosing traction when accelerating out of a turn.

Fuel economy might also have been an issue...

 

I have a 2003 Track that I take to road course a few times a year, have never auto-x with it. I stumbled upon a very simple way to reduce a LOT of understeer. I am running stock 245/45/18s on the rear, but changed the front from 225/45/18 to 245/40/18 which is the exact same diameter. It drives like a completely different car when going hot through a turn, almost no push and very easy to torque-steer.