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For those who race America's favorite Supercar!
Chevelle Tricks!
Wheel Hop
Wheel hop is something all Chevelle owners encounter at some time or another and it's one of the biggest problems we face. Nine times out of ten it's just due to sloppy suspension. I had used an old set of Lakewood Ladder bars to try and control it, but I got tired of problems they caused as well as the way they looked. Besides they weighed a ton! I thought about it a while and decided I really didn't want to spend a bunch of money on tubular rear control arms or new boxed arms. (I didn't really care what they looked like either). So I yanked my stock ones off, broke out my trusty arc-welder and with some scrap steel I boxed the arms myself. When I did it I made sure to box the entire length and while I was at it I went ahead and boxed the uppers arms too. I took care to weld them, starting in the center, about three inches at a time, letting them cool between welds. This kept them from warping. Next I bought some polyurethane bushings from Energy Suspension (about $75) and had them pressed in (another $25). When I got them back, I cleaned them up, gave them a fresh coat of paint (Which didn't look half bad, if I do say so myself) and re-installed them.
The next trip to the track was a wonderful suprise! No matter how I launched or how hard I pushed it, I couldn't detect even a trace of wheel hop. It was better than the old ladder bars ever were. This had a dramatic effect on ET's, because now I didn't have to feather the throttle out of the hole. If you're making more than 300 hp this is certainly a worthwhile endeavor. As an added bonus, unless you slide underneath the car, you can't see the modifcation.
Dave Kaveshan offered up this excellent tip that can be performed at the same time as the wheel hop mods!
Along with boxing the control arms, lowering the ride height of the rearof the car also helps. Of course this is limited by how big your wheelsand tires are. I raced my 65 El Camino for years with a 3.07 NON-posi 12bolt in it. With app. 350hp from the motor, traction was a huge problem.Since I couldn't afford a posi at the time, I lowered the rear of theCamino until the lower control arm was almost parallel to the ground.This relocates the Instant Center back and down. Now rather thansquatting hard on the leave(pulling the rearend up), the body staysrelatively neutral, allowing the weight to stay on the rearend andtires. While not a barn burner, I did manage as low as 2.01 60 ft timesat the track with a much practiced leave technique and on 235/60-14street radials. I raced many cars with posi's that could not match thatthough admittedly they sometimes didn't care about a good leave as muchas showing off. Currently I am rebuilding the rearend, finally, with anew posi and 4.56 gears so I'll get to start all over with tuning.
Don Seributra has a great idea for those whose wish to retain the rear sway bar.
While welding up the rear trailing arms, the lower arms can be modifiedwith gussets if an anti-roll bar is used. Inside the arm, considerinstalling 3/4" x 1" piping, and there is a trick: If using lower armswith bolt holes for the sway bar, insert the bolt to hold the "gussets,"and weld the pipe gussets to the control arm.
Thanks Don!
Air Bags
Ever notice how some cars launch straight and some cars look all twisted up as the leave the starting line? Well, one reason is that a lot of the cars that leave well are using an airbag. An airbag is a simple plastic bladder that is inserted in the rear coil spring and inflated. This helps control the compression that occurs in that spring and to some extent, the compression that occurs in the other, opposite spring.
A typical hard leaving Chevelle will, due to all the rotational forces taking place in the driveline, tend to lift the body on the drivers side and "plant" the body on the passenger side ( actually I believe this is due to the rear differential acting in the opposite direction, maybe some out there understands this better and could enlighten us as to the dynamics). This causes the car to waste a lot of motion that could otherwise be used to accelerate more quickly. By placing an airbag in the passenger side rear coil spring (Because of the way the car twists, it is not necessary to put a bag in the drivers side) and inflating it you can control the amount of compression that takes place in that spring effectively limiting it and help your car to launch straight. Getting the right amount of pressure is a trial and error deal, but I have found for me that 8-10 lbs. seems to be about right.
As an added bonus, airbags come in packages of two and you only need one, so you can sell one to another Chevelle buddy and recover some of the expense!
Try it, It works!
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