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Discussion Starter · #1 ·
Does anyone have some suggestions for alignment specs that would work best for autocrossing?The car is primarily a street car and I hope to hit a hand full of autocrosses this summer.I want the best handling without bad manners or tire wear on the street.My car is a 1995 9c1 with stock 17" SS wheels w/ 275/50/17 nitto "extreme perfomance" tires all around.It has the 1 1/4" front bar and HO bar on the rear.It also has lowered springs and bilstien shocks.
 
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Discussion Starter · #2 ·
My sway bars are not as stiff as yours (Hotchkis), but my car is set up for autocross and the road course. Here are the alignment specs that I use:

Camber: -1.0 deg, each side (+/- 0.25 deg)
Caster: +4.0 deg, each side (+/- 0.50 deg)
Toe: 1/16" to 1/8" toe IN

The toe in helps keep the street manners of the car - no wandering on the highway. It is perfectly streetable, but this setup will definitely cause your tires to wear a little faster. I figure - F*ck it, whats a couple thousand miles less on a set of tires if it makes the car turn this well? ;)
 
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Discussion Starter · #3 ·
Thanks for the info. I understand why a little neg camber helps, but what effect does pos caster have? Also have you found the softer hotchkis bars supperior to the ho/fcar?The front bar also limits my turning radius (especially w/ the 275s).Does the hotchkis front bar illiminate this problem? Thanks again!
 
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Discussion Starter · #4 ·
Here is another option that works well with the HO/HA bars.

Camber -.5 degrees
Caster + 5.0 degrees
Toe = 0.0 degrees

More caster improves straight ahead driving,and Zero toe in improves turn-in on the auto X course.
Just know that driving down the highway your tires will be toed out slightly.
 
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Discussion Starter · #5 ·
Our cars seem to have the same problem, as they get older. The springs tend to sag a little so when you have your alignment done make sure you are in your car. The weight will make a difference. Try it for yourself. After the alignment is complete but before they take it off the rack, go sit in your car and see if the toe changes. I think you will be surprised.
-Jose
 
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Discussion Starter · #7 ·
I was thinking today. If you had a low tank of gas when your car was aligned, when the tank is full it could throw off the alignment. I have no idea what my SS was aligned to. The shop got it to track straight and it does not wander allover the road as much so I am happy. Ill stick with this shop.
 
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Discussion Starter · #8 ·
Originally posted by AllenIDOXLR8:
Here is another option that works well with the HO/HA bars.

Camber -.5 degrees
Caster + 5.0 degrees
Toe = 0.0 degrees

More caster improves straight ahead driving,and Zero toe in improves turn-in on the auto X course.
Just know that driving down the highway your tires will be toed out slightly.
I was going to make the same recommendation for toe, but you beat me.

From a purely tire wear perspective, you generally want to increase toe-in as you increase negative camber. The toe-in will help distribute the inside tire wear more evenly across the tread. But, from a handling perspective, these things actually cancel each other out, so go easy with the toe.

I'm still in need of a good shop. Anybody know one in the Newport, RI area? The Town Fair Tire that used to be on my list of Good Alignment Shops in CT just fell off it when a new tech gave me a huge run around during the alignment. Still pissed about that one...
 
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Discussion Starter · #9 ·
Would you be able to get a proper alignment if you had two different sized tires in the front than in the rear? I have stock BFG's on the front and 275/40's on the rear.
 
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Discussion Starter · #10 ·
Considering the each wheel sensor for the various alignment machines clip to the rims of the wheels, yes. The only thing I can see the tires in the front effecting is if you were trying to calculate the degrees required to make a linear toe-in distance, like 1/8" at the tread for example.
 
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Discussion Starter · #11 ·
Well some tire shop turned me away for an alignment today because of the difference between the fronts and the rears. I was alittle confused to say the least.
 
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Discussion Starter · #12 ·
Originally posted by Kevin Moore:
Considering the each wheel sensor for the various alignment machines clip to the rims of the wheels, yes. The only thing I can see the tires in the front effecting is if you were trying to calculate the degrees required to make a linear toe-in distance, like 1/8" at the tread for example.
I was always wondering about how the rear end is shifted a little more to the right, causing an inaccurate reading with the wheel alignment sensors.. Interesting.
 
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Discussion Starter · #13 ·
I'm getting an alignment tomorrow before my first open track day. I'm running HO bars, crappy 275/40/17s, trimmed Rustic 750's up front and Vogtland rears. Is there such a thing as too much negative camber up front with stiffer springs and bars? I was planning on going -2.0 on the camber, but LeadSSled and AllenIDOXLR8 are running a lot less than that. I'm really not all concerned about tire wear. Any suggestions would be very welcomed.
Thanks
 
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Discussion Starter · #14 ·
I will be going to -2 degrees camber aligment this spring before the autocross season starts. The -1 degree alignment was a compromise on my part to reduce tire wear on the street. My car no longer gets many highway miles and is trailered to events, so tire wear is less of an issue for me. But be advised that the tires will wear quicker with this amount of camber.

I haven't done the research yet to determine if a different amount of toe or caster is recommended for this amount of camber. Maybe Ed of one of the other folks with expertise in this area will pipe in on this.

[ 12-13-2006, 04:14 PM: Message edited by: LeadSSled ]
 
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Discussion Starter · #15 ·
Don't be afraid to go to -2 for a track event... but your tires won't last long on the street like that.

Some tires like more negative camber than others... I run -3 with sticky tires.
 
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Discussion Starter · #16 ·
True but only because we like to drive our cars on the street occassionally. If your car is not a daily driver, -2.0 degrees camber will certainly help turn-in. R rated rubber will stick better and last a bit longer with substantial negative camber on our cars. Doesn't do much for straight line tracking though.
 
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Discussion Starter · #17 ·
Originally posted by Rustic:
Some tires like more negative camber than others... I run -3 with sticky tires.
Can you get that much negative camber with stock A-arms and stock height springs? What caster and toe are appropriate for -2 to -3 degrees camber?
 
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Discussion Starter · #18 ·
FWIW, my car now has -2.5 deg camber, and around 4.0 caster (actual number is maybe 3.7?) with slight toe OUT. We might have been able to get SLIGHTLY more camber with my springs (approx 1" lower than stock SS), but not much. And I also have the "offset" upper cross-shafts with them flipped to enable more negative camber.

It turns in, well, WELL :D

I suspect tire life on the street to be fairly short. Not so much from the camber (Subaru experience at least has shown surprisingly good tire wear with lotsa camber) but rather the toe
 
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Discussion Starter · #19 ·
I think I'll go with -2.0 camber and 1/16 toe in. Try it out, and if it's wearing my tires a tad too much on the street, even with as little as I drive it, I'll dial it down a bit.

On another note, how important is having the driver's weight in the passenger seat when it's getting aligned? Should I take off work early to go sit in it while its getting aligned?
 
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Discussion Starter · #20 ·
It'll change the settings a little.

That said, a GOOD alignment shop should have weights around (can be as simple as thrift-store weights from an old weight set or even well-sealed sandbags) they can throw in the driver's seat to simulate your weight. No need to be there in person.

If the shop gives you the "deer in headlights" look when you ask for them to do this, it's a good sign you have NOT chosen wisely on which shop to do the alignment ;)
 
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