Impala Forums banner
1 - 1 of 1 Posts

· Registered
94 Posts
Discussion Starter · #1 ·
A little disclaimer: Anything you read in the following will be tried at your own risk. Neither the author, administrators, owners, moderators, or anyone else but yourself will be responsible for any damage done to your car, yourself, or anyone/thing else. You are the ultimate responsibility to yourself and your car. Be smart, be careful, be fast.

This is aimed specifically at RWD cars.

If you have "frame slapper" traction bars on your car take them off and beat the guy who sold them to you with them, then beat yourself, then throw them away. Use them to sit a motor on. THEY ARE WORTHLESS.

Here's a little "how it works" on axle wrap.

When you hammer the gas from a standing start, your tires don't want to roll. As the torque of the axle shaft trying to rotate the tire, rotates the tire, it also rotates the axle housing the opposite direction.

That's what it does to your leaf springs.

What "frame slappers" or traction bars do is as the axle wraps the frame slappers rotate up until they come into contact with the frame, then they "push" the rear springs down using the axle's wrap to increase traction. The big problem is that it takes time for the axle to wrap enough for them to be useful.

Here's what to do. On the cheap, in one afternoon. I'll do the fancy expensive way afterwards.:biggrin:

When you mount an axle on leaf springs the two halfs of the springs (relative to the front and back of the axle) act as seperate springs, so we'll think and talk about them as such.

After you take them off and beat yourself with them, and throw them away, you weld or clamp the front half of the springs. Yep. Weld them suckers solid. Now what you have is trailing link with rear mounted semi-elliptical springs. It'll make your car ride marginally rougher, but it's all about going fast right? That takes care of the front springs wrapping. As for the back springs, we want them to wrap, we just want to utilize it to increase traction. The easy way. A pinion snubber.

A pinion snubber stops the pinions upward movement and forces the rear end downwards utilizing the rear springs tendency to wrap to increase traction.

The simplest snubber is a suspension bump stop welded to a bracket with about a half inch clearance between the top of the stop and the body. Zip tied onto the pinion housing of your axle. Good for a couple of runs. Let's do it right though.

Fabricate a bracket out of mild steel welded to the axle pinion housing to mound your snubber, then mount your snubber on a bolt so that you can run it up for less clearance on race day, and back down for daily driving. Weld a plate on the body about 6x6 for the snubber to strike, don't want to bend the body.

OR you can drill a hole in your body above the pinion housing, and weld a piece of steel (6x6 should do adequately) to the body so it won't bend, then weld a nut to the steel. Run the bolt through, then attach the bump stop to the end. Run it down for race day, and back up for daily driving.

Now. To do it not on a budget, you can buy a lot of traction devices out there to do the same things. trailing links, dudder bars, pre made pinion snubbers of many different designs, non frame slapping traction bars.

I GUARANTEE that if you weld/clamp the front springs and put a decent pinion snubber on your car it'll run much faster than stock, or with frame slappers.

Read up on Sox and Martin. They were the big drag guys back in the early sixties, and if i remember right were the first ones to do the pinion snubbers to any degree. IT works out well.

Other drag tricks:

Wash and wax your car the morning before the race. 1 tenth. Get some 2 inch wide masking tape, and mask every body gap hood doors trunk bumpers to body headlights, turn signals, taillights, and climb in through the window, or if required to open the door, just don't do the driver's door; take off the windshield wipers and arms, and the antenna. You'll gain 2 tenths. Take some cardboard, or construction paper and cover up all the vents in the front bumper, and the grill. You'll gain another tenth or 2. Take your wide front wheels off and run 2 doughnut spares. 2 tenths. Whoah, almost half a second? Put some plastic hubcaps covered with cardboard on your wheels, cheap smoothies. half a tenth. take everything you don't need out of the car. Back seat, tires, subwoofers, spare tire, jack, run on half or a quarter tank of gas. a tenth or 2. Damn, almost a second already. play with tire pressures. you can gain a few tenths just from that. run the fronts as hard as possible, and the rears soft. take your 18 inch wheels off and put on a set of 15 inch steelies. get the widest, lowest profile tires you can fit. check out tire compounds. some non studded snow tires are really sticky and make geat poor man's drag radials. Smaller diameter tires will decrease your overall gear ratio, like going from a 3.42 gear rear end to a 3.56. maybe 3 tenths. remove as much weight from the FRONT of the car as possible. light front, fast car. Perfect your launch. turn off the traction control and abs. Pull the fuses. A little tire spin can be good, especially with a motor with a higher hp curve. turn off your air conditioning, and all electrical accessories. if able to, run only the belt for the alternator. CONSISTENCY! CONSISTENCY! CONSISTENCY!

I bet with all you've learned today, you'll run 1.5 to 2 seconds faster in the 1/4 mile.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.