QUESTION 1

Tim,

I race a 2950-lb 10.5 wide tire car with a 4-link rear suspension and double adjustable rear shocks. I was wondering how you initially pick out the 4-link intersection points, i.e. how high up and how far out?

What do you recommend the rear shock settings to be? The rear shocks are Koni double adjustables. I know this is baseline stuff, but could you explain the changes that may need to be made if the car shakes the tires, like do this with shocks or this with the 4-link, etc.

Thanks, Tim!

Bob

Dear Bob,

We use past performance to pick a baseline for a particular combination. For your chassis I would start the four-link out at 52 to 58 inches long and 4 inches high. The shocks will need to be two to three sweeps from tight on the extension and six clicks up from loose on the compression.

There is a lot of data that determines what to do if a car shakes the tires. Engine power, transmission ratios, tire size, clutch settings, tire pressure, weight percentages, etc. are just a few things that will factor into what changes will need to be made. I know I am not totally answering your questions, but there is just a lot more than one thing to look at when a car is not handling correctly.

When a car shakes, it is knocking the rear tire out of shape and then driving over that mis-shaped tire. Look at why it is out of shape. It can be too much clutch or not enough, down on power or not enough power for the ratios it is pulling, poor race track conditions, shock settings, four-link position, etc. I have seen teams with years of experience fight tire shake race after race until they finally hit on the cause or it goes away with several small changes.

I hope I haven't confused you more. Good luck and be safe.

Tim

QUESTION 2

Dear Tim,

I am getting into street racing with a Chevy S-10. I am wondering how to get my little truck to hook up and leave my competition. Currently, I am running a .030 over 350 with 10.1 flat top pistons, with tight chamber double hump heads. I have an Edelbrock air gap, cam, 750 carb, turbo 350 full manual transmission, stock 7.5 rear with a mini spool and 373 gears. Wheel spin is a big problem.

Thanks for the help.

Michael Evans

Michael,
An S-10 truck with a decent V8 is going to spin the tires uncontrollably unless you do some suspension work. I didn't see any mention of traction devices, so I am assuming it is all stock. Try to start with a good set of ladder bars and adjustable shocks. That is an inexpensive way to put some bite back into your chassis.

Trucks in general have a hard time hooking due to the low amount of rear weight percentage available to them. The next step is to fit the largest rear slick under the truck that you can, even if it means narrowing the frame and installing wheel tubs.If you do this and get it set up by a reputable chassis shop, your traction problems will be greatly reduced.

Tim