View Full Version : Alignment Help for HPDE on a street car


01 ss vert
02-22-2010, 02:43 PM
I'm doing my first HPDE in 2 weeks and I'm trying to get the car ready for it.

I need help on alignment specs. the car is driven all the time on the street (12,000+ miles a year) so I don't want anything too agressive for tire wear reasons. I'm getting the car aligned in 4 days.

Suspension mods are as follows

Front: Stock shocks, Sportline Springs, 275/40/17s, Stock Sway, Poly bushings/End links
Rear: Koni 4s, Adj. Panhard, Adj. Control Arms, BMR Springs, 315/35/17s, Stock Sway, bushings/End links

I did an oil change the other night and noticed my driver side inside tire is having excessive wear. the passenger side is fine.

Any suggestions would be great. I do autocross the car, but overall I want a nice alignment for agressive street/auto cross with limited tire wear in mind. Help with caster, camber, and toe specs is appreciated.

EchoMirage
02-22-2010, 06:52 PM
camber -.5/1
caster +4/5
toe 0.0

01 ss vert
02-22-2010, 09:00 PM
Good. Those were in the range of what I was thinking as well.

SIK02SS
02-23-2010, 10:20 AM
-1 camber is nice, but if you drive a lot on the streets..holy tire wear batman! lol

i think i'd like -.75 as a better balance..but my driving is probably different than yours

01 ss vert
02-23-2010, 12:06 PM
Can you describe the driving difference between a -1, -.75, -.5, -.25 camber setting?

Is it 'night and day' or even 'seat of the pants difference' like caster adjustments?

MadIceV8
02-23-2010, 12:38 PM
-1 camber is nice, but if you drive a lot on the streets..holy tire wear batman! lol

i think i'd like -.75 as a better balance..but my driving is probably different than yours

On my BMW 330ci with the M package... factory camber is -1 in the front and -2 in the rear :punch:. Handles good, but not a fan of the tire wear.

On the Camaro I run the specs EchoMirage mentioned.

OffspringZ28
02-24-2010, 08:32 PM
What tires are you using for your HPDE?

BobP
02-24-2010, 08:57 PM
You should ask them to check your max negative camber during alignment just so you know. I run -1.5 for V710s on the track and leave it there for the street on KDs. Tire wear is OK, but it gets grabby on some road crowns.

BobP

01 ss vert
02-25-2010, 10:09 AM
What tires are you using for your HPDE?

275/40/17 nitto 555s front
315/35/17 sumitomo radials HTR? The cheap 315 street tire they offer, I can't remember the specifics

I have some old V710s mounted on another set of old wheels (275s on all 4 corners), but they are very used and might have 2-3 autocrosses left; I would surely cord them in the first of 5 20 minute rounds at the HPDE. I was told it's still a blast on street tires, so I'm going that route.


You should ask them to check your max negative camber during alignment just so you know. I run -1.5 for V710s on the track and leave it there for the street on KDs. Tire wear is OK, but it gets grabby on some road crowns.

BobP

Mines already VERY grabby on road crowns. I'll have him check this. Thanks.

EchoMirage
02-25-2010, 11:50 AM
street tires are all you need for an HPDE. its not a race, there is no time, so why bother blowing money on competition tires? if you get more into it, and plan on going several times a year, then by all means get a set of dedicated track tires.

dont bother with old 710s. if theyre anymore then one season old, theyve heat cycled themselves to death and are as hard as rocks. i wouldnt use them for anything at all, other then maybe a burnout/smokeshow.

keep an eye on your pressures throughout the day and youll be fine. you can also tell how your driving is by tire wear. if you wear them down alot, its because you havent found the right line around the track. if you make the day without that much wear, it means youre on the line and not making the tires overwork themselves.

mitchntx
02-25-2010, 01:54 PM
275/40/17 nitto 555s front
315/35/17 sumitomo radials HTR? The cheap 315 street tire they offer, I can't remember the specifics


That kind of mismatched tire size and track width is going to make the car handle really squirrely.

It will plow like a John Deere coming off the corners.

And you probably aren't going to be any better off with worn out R compounds. However ... if you gottem, then use'em up. They're doing nothing but getting worse sitting in the corner of the garage.

Have fun and report back ...

01 ss vert
03-01-2010, 03:06 PM
well I got the car aligned! The shop was great. the guy running it let me work on the rear (adjustable LCAs, panhard) while on the rack to get the right thrust angle. Once I was done, we worked on the front and got it to my specs. It's rare a customer gets dirtier than the mechanic. I was covered in dirt, but it was fun. This is what I got….

camber -.5 to -.6
caster 4.5
toe 0.08 degrees (usually this is in inches, so I'm not sure what that equates to in inches)

Thrust angle was .5 degrees when I showed up, but we got it to .09-.10 with the panhard and driver side LCA adjustment. Took a lot of torque and adjustments, but we got it there. the instant display changes was nice! The car still wants to go slightly to the right at high speeds, but I semi blame this due to the unever tire wear???

one last question…..tire pressure recommendations for the event? Should I go staggered (rears lower than fronts) or have it all the same on all four corners?

Here is a link to the track diagram:
http://images.google.com/imgres?imgurl=http://www.trackpedia.com/mediawiki/images/thumb/f/f1/Nash.jpg/800px-Nash.jpg&imgrefurl=http://www.trackpedia.com/wiki/Nashville_Superspeedway&usg=__3ctfDn2LvNwgapnyx0Q6Y31TJ9g=&h=575&w=800&sz=172&hl=en&start=16&um=1&itbs=1&tbnid=gMscPkJJZvu5RM:&tbnh=103&tbnw=143&prev=/images%3Fq%3Dnashville%2Bsuper%2Bspeedway%2Bmap%26 um%3D1%26hl%3Den%26tbs%3Disch:1

EchoMirage
03-01-2010, 06:12 PM
pressures will change alot when heating up. try for 37ish hot front. you can go lower then normal in the rear, since the sumis need to flatten out some. stay 35 or so hot.

also, if they dont have any, bring white shoe polish or chalk, and mark 3 spots on the tires. use that as a guide for pressures.