AutoXSHO
SHO Member
Just thought I'd finally share with the group some of the alignment specs I played with this autocross season on my '95 SHO. An alignment is the least expensive but most noticable handling "mod" you can do to your SHO. If done correctly, a good alignment improves not only the performance of the car but also the feel of the car as you drive down the road.
First, set front toe. Front toe-in (as set from the factory) dulls the steering response and slows the transient behavior of the car. It makes the car feel heavy, but it also makes it stable on the freeway. I like zero toe on my SHO, maybe 1/16 or 1/8" of toe out if you're an autocrosser. Zero toe gave me plenty fast steering but the car is easily driveable on the street and brainless on the freeway.
To set the toe, you don't even have to get the front end up. Loosen the jam nuts on the outer tie rod ends and the inner tie rod end boot clamps. The cheap, easy way to set the toe is to get a length of 2x4 that is fairly true. It honestly doesn't have to be perfect. With the car on level ground, and the steering wheel perfectly centered, push the 2x4 up against the front of the tire tread. Make a mark on the 2x4 where the center of your treads hit it. Do the same, with the SAME SIDE OF THE 2x4 at the rear of the front tire treads. Measure the distance between each set of marks and take the difference. This is twice the toe. I think you will find it is usually 1/8" or more from the factory.
To zero out the toe, just turn the now loose tie rod with a channel locks, turning the same amount of turns on each side of the car, until you get the same measurement at the front and rear of the tire treads. Tighten the jam nuts and the inner tie rod end boot clamps.
To set front camber, pop the hood, jack the car up and remove the strut tower covers. Note the three nuts and the strut top plate. This plate is riveted from the factory to the strut tower. You need to break the welds if a shop hasn't already done it. I used a 3/8" drill and a small chisel. Drill a hole through the rivet and chisel under the strut plate. It will pop up at each rivet.
For camber, I like to run the maximum. This isn't much on a SHO anyway, around -2 to -2.5 degrees. -2 degrees has worked very well for me. If you drive hard, -2 degrees will keep the shoulders of your tires in good shape, while drastically increasing cornering force ability.
I won't go into how to measure camber as it is fairly straightforward and you can look for instructions on the net, or by searching the TechSHO archives at Topica.com.
To set the camber, move the strut plate towards (for more negative) or away from the engine on each side. Balance is crucial here. You don't want more camber on one side of the car than the other - it will make the car behave different in transient responses.
Caster is the angle of the strut relative to vertical as you are looking at the face of each wheel. Positive caster is when the top of the strut goes back from the bottom of the strut. The advantage to more positive caster is that it increases the camber gain as the suspension travels through its range. This increases cornering grip when you need it. The disadvantage, as I found, is that it dulls the steering response on the freeway. A car that is twitchy and simultaneously unresponsive is not good. I played with maximum positive caster for autocross, but then would return it to minimum positive for the drive home. I don't have a good way to measure caster, but an alignment shop would.
Unfortunately, unless you have adjustable rear control arms, the rear alignment is not adjustable. On my SHO, I have 1/16" of rear toe in from the factory and 2 degrees of negative camber. If you have the ability to adjust your rear alignment, I would shoot for zero rear toe of 1/16" of toe in, and .5 to .75 degrees negative camber.
I had good results with these settings this autocross season and feel they are good for any autocross or street-driven SHO.
John V
First, set front toe. Front toe-in (as set from the factory) dulls the steering response and slows the transient behavior of the car. It makes the car feel heavy, but it also makes it stable on the freeway. I like zero toe on my SHO, maybe 1/16 or 1/8" of toe out if you're an autocrosser. Zero toe gave me plenty fast steering but the car is easily driveable on the street and brainless on the freeway.
To set the toe, you don't even have to get the front end up. Loosen the jam nuts on the outer tie rod ends and the inner tie rod end boot clamps. The cheap, easy way to set the toe is to get a length of 2x4 that is fairly true. It honestly doesn't have to be perfect. With the car on level ground, and the steering wheel perfectly centered, push the 2x4 up against the front of the tire tread. Make a mark on the 2x4 where the center of your treads hit it. Do the same, with the SAME SIDE OF THE 2x4 at the rear of the front tire treads. Measure the distance between each set of marks and take the difference. This is twice the toe. I think you will find it is usually 1/8" or more from the factory.
To zero out the toe, just turn the now loose tie rod with a channel locks, turning the same amount of turns on each side of the car, until you get the same measurement at the front and rear of the tire treads. Tighten the jam nuts and the inner tie rod end boot clamps.
To set front camber, pop the hood, jack the car up and remove the strut tower covers. Note the three nuts and the strut top plate. This plate is riveted from the factory to the strut tower. You need to break the welds if a shop hasn't already done it. I used a 3/8" drill and a small chisel. Drill a hole through the rivet and chisel under the strut plate. It will pop up at each rivet.
For camber, I like to run the maximum. This isn't much on a SHO anyway, around -2 to -2.5 degrees. -2 degrees has worked very well for me. If you drive hard, -2 degrees will keep the shoulders of your tires in good shape, while drastically increasing cornering force ability.
I won't go into how to measure camber as it is fairly straightforward and you can look for instructions on the net, or by searching the TechSHO archives at Topica.com.
To set the camber, move the strut plate towards (for more negative) or away from the engine on each side. Balance is crucial here. You don't want more camber on one side of the car than the other - it will make the car behave different in transient responses.
Caster is the angle of the strut relative to vertical as you are looking at the face of each wheel. Positive caster is when the top of the strut goes back from the bottom of the strut. The advantage to more positive caster is that it increases the camber gain as the suspension travels through its range. This increases cornering grip when you need it. The disadvantage, as I found, is that it dulls the steering response on the freeway. A car that is twitchy and simultaneously unresponsive is not good. I played with maximum positive caster for autocross, but then would return it to minimum positive for the drive home. I don't have a good way to measure caster, but an alignment shop would.
Unfortunately, unless you have adjustable rear control arms, the rear alignment is not adjustable. On my SHO, I have 1/16" of rear toe in from the factory and 2 degrees of negative camber. If you have the ability to adjust your rear alignment, I would shoot for zero rear toe of 1/16" of toe in, and .5 to .75 degrees negative camber.
I had good results with these settings this autocross season and feel they are good for any autocross or street-driven SHO.
John V
. Yes, the extra negative camber up front will cause inner shoulder wear if you drive long distances. As for stopping distances, I'll take the improved transient response and lateral grip and give up some stopping distance. Hmm... makes me think about finding an open parking lot and doing some braking tests...
