BTW... sorry for getting off topic from the original post!

 

Spider, you were right, it was Sebring Silver. Just picked it up this evening. Gonna have a hard time sleeping tonight!

 

[QUOTE]Originally posted by rlawson [B]In my opinion, there is so much to learn about driving this car, that seat time is the most important investment that can be made.

 

In case it is helpful, here is a simple explanation of bump steer:

As the suspension travels up and down the alignment of the wheel changes to some degree from it's resting state. This can cause the car to travel more towards the left or right depending on how much the suspension is compressed (or extended) at any moment.

Cars with a bump steer problem tend to have more dramatic steering effects from one end of suspension travel to the other.

The odd thing is that a double-wishbone system (like ours) is supposed to be one of the best ways to minimize bump steer.

 

To build on what jschmidt wrote. More specifically, bump steer is the amount of toe (not so much camber) change that happens as the suspension moves up and down. With certain suspension setups, the direction the wheel is pointed in actually changes as the suspension moves up and down. On a car with a lot of bump steer you feel a fair amount of steering wheel movement when you hit a bump because the bump causes the wheel to point in a slightly different direction which causes pull on the steering wheel. If you ever drive an early 80's 911, it will be very apparent.

 

I'll contact King Motorsports about the rear bumpsteer fix. I find it very unnerving through high speed Esses, such as the ones at Watkins Glen. The stiff sidewall R compound tires really seem to aggravate the problem. It seems to me the fix might be in relocating the rear toe links, not the A-arms.

The Miata has no toe link, and if I'm correct, has no bumpsteer. The rear hub is bolted directly to the lower A arm through a pin joint, not a ball joint like on the S2ki. What about taking the s2000 toe link and attaching it to the lower A-arm? Then all the link does is control the toe-in to one setting thru the whole suspension travel.

 

Randy (rlawson). I'm going to try the 265's without the bar for now (the first year). I like the idea of returning the car to stock after the events (putting the stock tire/wheels back on after auto-x). Now that's 225/50's in front. In the back it would be 265/40's?

I may try the adjustable bar after I get a lot more seat time. Hopefully it won't be that difficult to adjust the bar to the stock stiffness after each event.

We can share notes as the season progresses.

Thanks Randy and everyone for the help.

Fred.

 

Be aware that the new Kumho series has only a 205/45-16 and 225/50-16 - at least, as listed by TireRack...

 

Jeff, I checked the tirerack site and it appears the Victoracer is sized in 225/50/16, 245/45/16 and 265/45/16. I'm guessing the 265's will fit. If not, I'll go with 225/50 and 245/45. Thanks, Fred.

 

[QUOTE]Originally posted by statueman
[B]Jeff, I checked the tirerack site and it appears the Victoracer is sized in 225/50/16, 245/45/16 and 265/45/16.