Page 1 of 3

VT1 - How Much Rear Camber

Posted: Sat Sep 15, 2018 4:37 pm
by psyolent
So the VT which I want to peddle around a track given its an S1 has non abjustable rear camber. Sitting on SL springs the rear camber is alot (how much I don't know) but you can see its excessive.
As this thing is going to be on a track where you actually want *some* negative camber, is this a bad thing? ie: how much negative is too much?
ie this much

Re: VT1 - How Much Rear Camber

Posted: Sat Sep 15, 2018 4:57 pm
by vlad01

Re: VT1 - How Much Rear Camber

Posted: Sat Sep 15, 2018 5:51 pm
by Charlescrown
For fun track days minus 2 on the rear and minus 3 on the front.But daily driving you get moderate to serious tyre wear.

Re: VT1 - How Much Rear Camber

Posted: Sun Sep 16, 2018 11:21 am
by immortality
For a race car when mileage isn't an issue some rear camber isn't a problem, if anything, desirable. The problem with the IRS is the change in camber/toe as the suspension moves through it's range of motion. Anything pre VX II (unless it's a HSV VT GTS) is more problematic as they don't have the extra toe link.

This covers the problem in detail http://www.whiteline.com.au/articles/WL ... e_link.pdf

Re: VT1 - How Much Rear Camber

Posted: Sun Sep 16, 2018 11:42 am
by Gareth
Interesting read there, basically the later rear ends sort out the bump steer and use less rear camber, there fore keeping the tyre tread at a more relevant angle to the road.

Re: VT1 - How Much Rear Camber

Posted: Sun Sep 16, 2018 11:48 am
by immortality
Fairly much.

The sad thing is (or so my understanding is) the original IRS system design had the toe links but Holden decided they weren't needed. My VS IRS has the ears on the hub castings where the original toe links would have been fitted.

Our VX II is running on Low springs (a touch lower than FE2 in the rear) has only very slight amount of rear camber but has no rear tyre wear issues.

Re: VT1 - How Much Rear Camber

Posted: Sun Sep 16, 2018 12:17 pm
by psyolent
On the hub castings yes, but the mounts on the cradle no - the later VXII rear cradle is better. I have access to one so I'll grab it and swap it. The amount of camber in the rear is too excessive and won't be good.

Re: VT1 - How Much Rear Camber

Posted: Sun Sep 16, 2018 12:23 pm
by immortality
Yep, they saved on costs not welding on the brackets for the toe links...

It's a shame I can't change the rear subframe on the VS to the later spec unit :(

Re: VT1 - How Much Rear Camber

Posted: Sun Sep 16, 2018 12:52 pm
by immortality
I should add that someone makes a kit that allows you to cut off the original subframe swing arm mounts and weld on new ones as well as modify the arms to help improve the geometry. There is a thread on the Commodores Plus forum that has pics of the mods.

Re: VT1 - How Much Rear Camber

Posted: Mon Sep 17, 2018 10:03 am
by psyolent