My car has the following suspension mods:

h sport camber plates
Alta rear sway bar 22mm
h sport rear control arms
stock r53 sport suspension struts and springs
17" yoko es100

what alignment setting would improve handling for autox?

thinking about close to -2.0 camber upfront to start with...

 

You can check over in the autocross section for opinions. I personally am running these settings for a car with TSW v.3 springs, Ireland fixed plates, 19 mm H&R rear bar, Hankook R-S2 tires.

front:
camber (fixed) 1.7 deg, 1.4 deg front (would use -2.0 with adjustables)
total toe zero

rear:
camber -1 to -1.2
total toe .18 deg. in

I use these for road driving as well; I am running STX class with a very small club, so I do not have much competition. I don't feel like compromising road stability with a more extreme setup that would give slightly quicker times. A slightly faster setup would use more toe-out in front, and near zero toe in rear. If you are using R tires, probably more front camber would help.

 

Grassroots Motorsports magazine did an article on this a while back. The author went on to do very well (can't remember if he won) at Nationals.

 

Front camber as much negative as you can (probably about -2.2deg). Max possible probably won't be the same on both sides, so get all you can while keeping them even. The limiting factor will be the springs running into the inside of the wheel well. Going to 2.5" diameter springs (I've done it, as did the GRM article) allows a greater range of adjustment. -3deg or more is great in sweepers, but I found that on our surfaces and courses my traction for accelerating and braking was compromised too much so I dialed it back a touch (-2.8) Your mileage may vary.

Rear I'd start with about -1.6 to -1.8 depending on how much rotation you like. Less rear camber will translate to more rotation. You've already got the larger bar on the rear, so I prefered -2.2F, -1.8R when I was using stock style barrel shaped springs up front. That gave the car a very planted feel that tracked well in quick transitions (typical courses in our local regions have plenty of slaloms and garages) but could still be made to rotate well for turns and tighter turns. You may prefer something else.

For toe, I used to put 25K miles a year on when street driving before I got a DD beater, so I always went for 0 toe front and rear. Toe is what chews up tires if you get aggressive with settings, much more so than camber. Again, this resulted in handling that worked well for me. If you don't think the car turns in fast enough, then you might try a little toe out up front (1/8" to 1/4", the latter being pretty aggressive relative to tire wear). If you do high speed track days, you might consider just a touch of toe in at the rear to make the car a little more stable.

That should get you to a good starting point. Have fun!

Scott
90SM

 

thank you very much for the feedback. I will set it up with -2.2 up front and -1.6-8 in the rear. I can play with the settings throughout the day as well.

Thanks again.

 

I assume you have a camber and toe gages? I'll figure you know this but if you touch camber then you throw out your toe.