what should i do to improve traction on street tires? i know that DRs would help a lot, but i drive my car a ton (put 13000+ miles on it since last may... 2000 over xmas break) and dont want to be replacing tires so often.

 

Good stiff LCAs and relocators.
Now some will tell you that relocators are only for lowered cars but they will also improve straight line traction by changing the instant center of the suspension.

 

It was my understanding that the only way to change the instant center on these cars was to change the torque arm because it is the only thing that controls the rotation of the axle housing.
http://www.baselinesuspensions.com/i...A_Drag_Car.htm
Here's a link to a drag racing suspension page. It talks about just about everything to do with setting up a suspension for optimum traction.

 

yeah, I don't think the benefit is from the instant center.

My LCA brackets were a definite plus though. With 100 pounds of gear in the trunk, my convertible's LCA's pointed UP on the axle when resting. I can only imagine it getting worse with squat. Wheel hop was bad on the street as a result... the springs and the LCAs decided to play "Push-A-War" with my rear and vibrated my fillings loose if I goosed it too hard.

With the LCA brackets on and the LCA's pointing slightly downward at rest, I'm sure they on level out when squating... and no more axle hop.... now it is a nice even "spinnnnnnn" sound.

My Nitto 555R's were great for daily driving. I ran them at 25psi for even tire wear, and kept them at 23 to 25 at the track (had to bleed them down between runs as they heated up fairly good) for best traction. My 2 sets each lasted 20,000 miles and ~20 passes down the strip. Not bad for $140 each.

Even if you don't go with DR's, you can still get some nice performance tires with 300 tread life or so. Look at the Firestone Firehawk SZ50's, or the Bridgestone RE730's for all-round street grip without breaking the bank (Michelin Pilot Sports and Goodyear Eagle F1 Supercar's are nice too... if you can afford the cost of entry ).

 

Changing the angle of the LCA changes the intersection point of the extended lines of the torque arm and the LCAs. That intersection being the "instant center" of a torque arm suspension.

 

Check out www.Spohn.net. good quality suspension parts...real good prices...I agree with all, LCA's relocation brackets, also adding an adj. torque arm...pinion angle, pinion angle, pinion angle!!! start at 2 deg neg in relation to the driveshaft...this is good for a street car and shouldn't cause excessive u-joint wear...
--Alan

 

Please listen to ABA383. My car is lowered, but yours might be a little lower than when it was new. Anyways, relocation brackets helped a little, Nitto's helped a little more, But the thing that helped the most was the Spohn adj. torque arm. Moving the pinion angle to just one degree negative made a big difference in how the car hooks.
Oh, and don't go by my track times, the car has a few issues that will be sorted out this spring.

 

I'm not trying to say the lca relocation brackets wont help. It was just that my understanding is that since the torque arm is hard mounted to the axle it is he only thing that affects instant center.
I know on a 4 link such as on a mustang the intersection of the upper and lower control arm is IC but on our cars it is where the end of the torque arm is. I know on a ladder bar the instant center is end of the ladder bar and I thought the torque arm was the same concept as that. It was my understanding that the lca's only locate the axle and dont control rotation of the housing.

 

They must because when I still used LCA and a torque arm my LCA were lower at the rear from relocation brackets. From all my hard launches, the floor started to wrinkle around the front LCA mounts from the amount of force pushing forward on the arms.

You can't compare a torque arm/LCA suspension with ladders bars or a 4-link system. It's designed and works differently. LCA don't transfer force upward like the torque arm does but they transfer force forward into the body pushing on the front mount.

 

That's exactly what I'm saying is that the LCA's control the foreward/rearward movement of the axle and the torque arm controls the rotation of the axle which is what lifts the car under acceleration and plants the tires into the ground. I have done quite a bit of research on older threads and there seems to be a lot of disagreement on how exactly instant center on our cars is calculated so I think you just go with what you believe.