Questions about Springs and Suspension

[Jay Mann]

Now that 33 Coyote is on the road, it is obvious that it has plenty of torque and horsepower. Getting all that power into the pavement is going to take some significant practise. As stated in another post, the big Wilwood Brakes are more than capable of eye ball sucking stops. The car has exceeded my expectations, but it is not in my nature to leave well enough alone.

So now I am interested in learning more about suspension and fine tuning the ride and handling of the car to suit the driving conditions in my area. After reading the excellent threads by Dan and Tom on both forums, I ordered the QA1 setup from Dan as soon as I ordered the kit. I fine tuned the shock mount bracket with a ball peen hammer ( it actually looks OK), the configuration of the shocks and springs fit into the car perfectly.

Tom mentioned the quality of the roads north of the Mason-Dixon line, well the roads north of the 49th parallel can be another story altogether.... Because of the large brakes, I have to use 17" rims on the fronts, the side wall height is limited by the need to run bike fenders ( no fenders will get a ticket from the local constabulary every time). The rear tires could be higher but the selection of tires that would work is limited. I am using Falken 452, 245/70/17 and 295/30/18 now. When these wear out I may change to the Azenis 615K which are available in a 295/45/18.

I am expecting to use two setups for the car, one for street and one for tracks days. If I have to change springs and tires for the odd track day, that is no problem. In fact the current confuration is probably very good for a track. So now I want to set the car up for everyday driving on Canadian city streets.

Question 1 - Spring rates - I do not understand why the rear springs are so much heavier than the fronts. I do not have access to the car for exact measurements, but the lever arm effect effect on inboard shocks results in approximately a 2:1 ratio, so the #450 lb/in front springs are effectively #225 lb/in. The rear springs are #325 lb/in. Since the weight distribution of the car is close to 50/50, I would have expected the fronts to be a little stiffer than the rear due to weight transfer when braking and cornering. Has anyone tried a #250 lb/in or lighter rear? The car has such a low CG that I do not expect to need sway bars for street use unless the springs get too soft.

Question 2 - Wheel hop - I have no experience in high torque light weight cars. I have spent enough time standing on the start line at a drag strip watching inexpereinced drivers to know that wheel hop after shifting can ruin a good day. When pushing the car a little I am experiencing wheel hop after shifting into 2nd and 3rd. After shifting I wait a split second before adding more throttle, but just a little too much and the back end starts bouncing. Any suggestions about how to reduce this effect?