We did the Upper Control arm swap on our ITR to get more caster and more prefered camber on the corners. (more negative on the outside, more positive on the inside).

I did not take the car out but the other driver says that the car has a less progresssive heavy turn in, then the cars darts to turn in and then snaps oversteer.

Well i figured that the heavy non linear turn in would occur with the car, but i did not expect that the oversteer would be so non linear. He said it was like having a huge sway bar on the rear.

Anyone have a clever input on to why this is happening? best i can figure is that the digonal weight shift from the front end rising more (due to the caster change) is causing the instide wheel loose weight and hense promote overstter, but can that much weight change really effect a 2400 lbs ITR?

+2 caster change on each side. With 1/8th toe out a side and zero toe in the rear. -2 degrees static camber.This is a stock ITR suspension with Koni Yellows and Hankook Z211 R comps.

We are using skunk2 arms, beacuse to change of the ball join position to the inside of the car to gain camber, this caused the kingpin inclination to change..could this cause this adverse effect alone? When coupled with additional caster?

PS: Anyone know what 1/8th toe is in degrees on a DC2

Thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B HATCH &raquo;</TD></TR><TR><TD CLASS="quote">PS: Anyone know what 1/8th toe is in degrees on a DC2

Thanks</TD></TR></TABLE>

No insight on oversteer concern, but toe would be roughly .16

 

I have not checked but adding caster changes kingpin scrub/kingpin inclination whatever you want to call it...the self-centering affect of the kingpin...I'll let someone else take over from here.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B HATCH &raquo;</TD></TR><TR><TD CLASS="quote">We did the Upper Control arm swap on our ITR to get more caster and more prefered camber on the corners. (more negative on the outside, more positive on the inside).

I did not take the car out but the other driver says that the car has a less progresssive heavy turn in, then the cars darts to turn in and then snaps oversteer.

Well i figured that the heavy non linear turn in would occur with the car, but i did not expect that the oversteer would be so non linear. He said it was like having a huge sway bar on the rear.

Anyone have a clever input on to why this is happening? best i can figure is that the digonal weight shift from the front end rising more (due to the caster change) is causing the instide wheel loose weight and hense promote overstter, but can that much weight change really effect a 2400 lbs ITR?

+2 caster change on each side. With 1/8th toe out a side and zero toe in the rear. -2 degrees static camber.This is a stock ITR suspension with Koni Yellows and Hankook Z211 R comps.

We are using skunk2 arms, beacuse to change of the ball join position to the inside of the car to gain camber, this caused the kingpin inclination to change..could this cause this adverse effect alone? When coupled with additional caster?

PS: Anyone know what 1/8th toe is in degrees on a DC2

Thanks</TD></TR></TABLE>

More caster will cause more weight jacking to occur, which means that more rear percentage of tire load will be transfered to the outside rear tire. This helps a car rotate better, especially in low speed corners. With more caster and no power steering, you will notice significantly more steering effort as well.

Snap oversteer the way you described it is an issue with not adequate suspension movement or some binding occuring in the rear (typicallly). Or, maybe you reassembled something incorrectly.

 

two words. bump steer. j00 fawked your bump steer good by swapping the uca's. swap them back and deal with low caster. it's not needed in a fwd anyhow.

 

1/8 inch toe out per side is too much IMO

 

I'm running 4.3* caster in my 00 GSR, and I don't seem to have any snap oversteer issues. 400/400 GC coils on Koni Yellows with GC upper mounts in the front, Comptech rear sway set full stiff, and SPC UCAs swapped with balljoints adjusted for max caster. 0 toe all around, 2.7* / 1.2* camber. DD / autox / HPDE car.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">two words. bump steer. j00 fawked your bump steer good by swapping the uca's. swap them back and deal with low caster. it's not needed in a fwd anyhow.</TD></TR></TABLE>

A valid point (mixed in with some |_33+ sp34|&lt; for some reason) concerning the bump steer. I don't have any issues with bump steer (that I can tell), but I was driving with 0.25* caster and a 3.5" drop before (stupid Ingalls camber kit screwing with caster if you don't keep the adjustments even), which gave me terrible bump steer. So my basis of comparison is screwed.