I'm trying to figure out the optimal alignment setting for my Z, especially tow. I want a fairly aggressive autocross setup, but not so aggressive that I'm driving backwards at the track. zgasm (my brother) tells me that he runs 1/16" out in the front and 1/32" in for the rear for autocross / track. I've also heard that I should max out the castor in the front, but I'm not sure if that can be adjusted. However, most alignment shops seem to work in degrees. Do you know how these numbers convert? Should I just calculate it based on the original outside diameter of my tire? Or does it go by the wheel diameter? Do you know what your tow / castor settings are in degrees? I have stock suspension except GSR Ti-2000 springs.

 

Most of us previously found that the optimal autocross alignment was so close to the normal street alignment that we just went with the street setup.

Of course, that IS on 275+ width tires (I run 285s or 295s, depending upon my budget at the time).

 

With stock suspension you can only adjust your toe setting in the front. 1/16 total toe out is a good setting, shop can convert that to degrees if needed. The rear you can adjust both toe and camber, If your setting up stock in front I would stay with the stock settings for the rear.

Your brother was probably taking about make camber not castor for your front setting.
I have adjustable control arms and run -2.5 camber and 1/16 to 1/8 toe out in the front.
Rear is -1.8 camber and 0 toe in the rear, with 255 tires all around.

If your new to racing just go race with the stock settings. Then you'll have a baseline to compare future changes to.

Have fun.

 

Thanks for the replies. I have 255's in the front and 265's on the rear on the stock track rims, but I'll probably go to 255's all around to stay legal for the STR class. Looks like I will go with about 1/16" total toe out in the front, and something close to 0 in the rear. I'll have to see what my rear camber is right now, but it looks pretty high, so I'll probably dial it down a bit. I wish I could adjust my front camber, but I'll have to save a bit for new control arms.

 

Put your money into a set of Hancook RS3's. Tires will be your fastest mod, you'll just be disappointed with your results with good suspension and average tires.

You can save some money on tires by getting 17inch rims. 255's in 17inch are $100 cheaper per tire than the 18's

 

Ya, tires make a drastic difference. I had the RS-3's for my last set, and they were awesome, but my lack of front camber caused the outside edges of the front tires to wear much faster than anything else. I now have the Toyo-R1R's, but they are a softer compound and it looks like they will only last me 3 track days and about 4 autocrosses. They overheat pretty badly on a hot day at the track, and they are also feathering badly on the outside edges in the front. I could compensate a bit with increased tire pressure, but then I get out of the sweet spot in grip. I'll definitely go with the RS-3's again next time (which will be very soon). As far as the wheels go, you gotta have money to save money.

 

Front anti-roll bar (34mm) helps a LOT.

 

I saved enough going with the 17s that it bought me 3 of the 4 wheels. Mb weapons from discount tire 17/9 with 17 offset.

Just food for thought.

 

I do have Stillen sways. I'm not sure of the mm in the front, but they are adjustable and I usually run the front at full stiff. I change the stiffness of the rear bar as my tires wear and the grip falls off.