rynberg

I would like to get some input regarding aligment settings with 18" wheels, specifically camber.

I am currently running the stock wheels/tires with the Pettit Long Track settings (-1.5 camber front, -1.3 rear). I really like these settings as my car is daily driven with auto-x and road course events. The settings seem a great balance between turn-in and tire wear.

I have recently purchased a set of Enkei RP-01s in 18" sizes.

Due to new springs seats, an off-track incident at Buttonwillow 2 week ago ( ), and the switch to 18" wheels, I am getting a new alignment.

The Pettit Long Track settings for 18" wheels are -0.8 camber front, -0.2 rear. I am aware that shorter sidewall tires require less camber but those settings seem conservative. I want to maintain the same balance of turn-in vs tire wear I have now.

I am looking for input from those having experience with camber settings with different wheel diameters. Keep in mind that the car is daily driven. Thanks.

Howard Coleman

iTrader: (6)

i run 1.2 neg front and rear on the street and like it. that's w 18X8.5 and 18X10 Enkeis/Toyos... w a 25 inch ride height at the wheel wells. i think thats the ultimate street setup. i run more camber at track events and set it w a pyrometer. the camber setting i run has not caused undue tire wear BTW. 30 psi front 27-28 psi rear cold tire pressure.

howard coleman

rynberg

Thanks very much for your input, Howard. It seems like the equal camber all-around would lead to a little more understeer, isn't that correct? I'm already going from same width wheels/tires to a staggered setup (8.5 with 235/40, 9.5 with 265/35), so I'm not sure how much more understeer I want to dial in here!

manatecu

iTrader: (6)

I use the Pettit Street/Strip aligment specs for 18" and I really like the.

Howard Coleman

iTrader: (6)

i think we are fairly close re camber... 1.2 or 1.5...
the key to making any front engine rear drive go fast is rear end stick. after all the optimal engineering is done the challenge is always hooking up the rear.
softer rear springs, less rear roll stiffness, less rear tire pressure, bigger rear tires and more rear camber all help. ( don't forget to run 2-3 pounds less air in the rears, it makes a huge difference ). BTW, no reasonably setup fd should ever understeer... so i don't think you'll need to worry about that. so you know the rate of your HKS springs? also, how do you have your shocks set front to rear.
howard coleman

rynberg

Thanks for the info.

rynberg

Thanks for the info, Howard.

My HKS springs are progressive, but their average rate is ~395/280. I am running Konis, on the track, fronts are 1/4 from full hard, rears are 1/2 turn from full hard (there's two full turns from full soft to full hard, I believe). So far, I have been running 32 psi cold in the tires, which is about 36 psi hot. I don't use a pyrometer (not that hard core yet, I guess), but my tires have wear patterns either right at or just slightly over the edge of the sidewall, so I feel my pressures are pretty good.

I just installed new upper spring seats up front in order to fix a sagging problem. If the new seats don't fix it, I'm just going to go ahead and get coilovers, either converting my Konis with the GC setup or the JIC FLT-A2s.

Howard Coleman

iTrader: (6)

i think your spring rate is fine. i don't prefer progressive springs as they change rate in the middle of the corner during turn in and are harder to drive. if i was driving your car i would soften the front shock setting a touch and soften the rear so it was 1/2 turn from full soft. i would lower the front tires to 30 cold and the rears to 27 cold.
if you do consider coil-overs please do yourself a favor and carefully consider the Tein HAs. they are beautifully built and quite (approx $900) inexpensive. monotube shock for more precise settings, 16 clicks adj, and the right spring rate... 566 fr , 422 rear. i have run them for 4 years. i have never been beaten on the track and they run great on the street. i have a shock dyno and have dynoed the shocks in all 16 settings at all shock speeds.
i am sure there are other good packages but i know the Tein HAs work.
howard coleman

rynberg

Thanks again. I will consider your advice. I don't prefer the progressive springs either, but they are a stopgap.

DamonB

rynberg try some runs with less rear shock like howard says; the power will go down much sooner and easier. I keep finding that the car likes lots of shock and bar up front and not near as much of either in the rear. I normally end up with 2-3 pounds more tire pressure in the front too.

(90% of the time I have 1.5+ turns from soft in the front and 0-.5 turns from soft in the rear.)

...just got back from Test and Tune on brand new tires and new chassis settings. The car has to be driven a little differently but it is hooked up better than ever right now.

Rx7@Rocketship.com

In my quest for feedback on this 18" wheel alignment question, does anyone have anything else to add?

Rynberg... How is -1F 1/32" toe in and -.5R 0 toe doing for you?

Cheers everyone.
David

rynberg

Car feels good on the track, at least it did the last time I was on the track -- 7 months ago...

I also get nearly perfectly even wear at the track and have noticed no uneven wear problems in several thousand miles of street driving.

I'm going to take Damon and Howards advice next time and dial in just a hair of rear toe-in at my next alignment. However, with the staggered tire setup and the smaller 94-95 rear anti-roll bar (as compared to Damon's 93 bar), I have less oversteer than with 93 cars, so my settings might not work for 93s.

gfelber

Rynberg,

I run 1.8 neg camber up front and 1.2 on the rear. I prefer more camber than Pettit's recommendations for flexibility and due to the fact that I typically run Hoosiers which require more camber.

Spring rates are 650 front and 450 rear, tires 285- front and 285- or 305- rear (big rear helps reduce oversteer with the 93 rear bar and other stuff, but that's another discussion).

I run 1/16" toe up front and find my car really dislikes any rear toe with the M2 toe links/trailing arms. Rear toe caused my car to become VERY twitchy and unstable under braking/trailbraking.

Gene

rynberg

Thanks for your settings, Gene. I won't run that much camber as my car sees more street miles than track miles and I'm still using street tires at the track.

You run stiff springs...

I'm surprised that a little bit of rear toe-in would make your car unstable, it seems like it would make the car more stable. Howard, Damon, and others have suggested a little bit of rear toe-in to make it easier to put the power down exiting a corner. I wonder what differences there are in car setups to create such an opposite reaction?

POM HB

Another good thread.

vchacon

Great information guys. Do you guys go to a speciality shop for a suspension tuning or do it on your own? I'm working on replacing my worn out suspension. After which I'll be the newb at the track.

rynberg

Take it to specialty shop. You CAN rig up a home alignment setup but a good shop will use a Hunter digital alignment rack that will do a much better job (and can do it with you IN the car). Unless you are constantly changing camber settings (not something a track novice would be doing anyway), I would just use a shop.

Alpine

In socal area, for specialty alignment you must go to west end alignment, Darrin Nishimura the owner is one of the best alignment tech around.

West End Alignment
Address: 18008 S Vermont Ave, Gardena, CA 90248
Phone: (310) 808-9233

If it's a street car, and you just need stock alignment setting, Sears is not bad.