12" spindle bumpsteer

[maineSS]

Anyone have bumpsteer difficulties after doing the 12"
spindle swap? If so, was it more noticeable in bump
or droop? I just got the RCA bumpsteer program from
Steve Smith Autosports, and will try and model stock
bumpsteer with the B-body spindle bumpsteer. It requires
32 chassis measurements for each side, some of
which are challenging. If I know where the real-world
bumpsteer occurs, I can see if the program agrees,
then go back and see what's needed to fix it. After I
do my spindle swap, I can post the results of stock
vs B-body, and whether the program works. Thanks

 

[GNVAIR]

Go to www.montecarloss.com and look for Jeff Davidson. He made a kit to eliminate the bump steer. He has a website as well http://jeffd.50megs.com/bump_steer_mods_page.htm

 

[bruce]

Originally posted by maineSS
Anyone have bumpsteer difficulties after doing the 12"
spindle swap?

Yes, it's noticeable.
However, if you're running high rate front springs it's not too bad.
I, for one, will be curious as to what you find.

I found with the increased stopping capacity, the stock springs were way too lame, ie lots of dive on heavy braking.

 

[maineSS]

From what I've heard, G-body bumpsteer geometry is poor
to begin with, and dropping the outer tierod 1/2" with the
B-body spindle makes a bad situation worse. Since the
increased leverage of the B-body spindle frequently drops
the chassis ~1" (depending on spring rate), bumpsteer
could be worse in droop than bump- or so I've heard.
Also, antidive geometry could be affected, which would
definitely be very noticeable on braking- that's another
item to check. Again, experiences like this provide valuable
insights on what to check with the program-keep them
coming! Thanx.