nukblazi

Noticed it right after I left the shop yesterday. Has anyone else experience this?

Does anyone have an idea for a fix?

Thanks,
Thomas

x838nwy

What do you mean by a 'rollbar'? People seem to have different names for the same part and same name for different parts.

Where is it installed? Front or rear?

If you increase roll stiffness in the rear (by installing stiffer anti-roll bars) then you should experience oversteer. If you increased the roll stiffness in the front you should understeer.

evo ippo

iTrader: (40)

+1 Roll Bar? at first look i was thinking of a roll cage but thinking about it are you talking about a sway bar????

nukblazi

Not and "Anti-roll bar", I had an Autopower rollbar installed yesterday. I have a rear "anitroll bar", derlin rear control arm and toe link bushings as well. The car handled great after Robi installed those. Yesterday, on the way home from the shop after the Autopower was installed, the car was understeering. I am thinking from the additional weight high and rearward in the car.

WarmPepsi

iTrader: (35)

...judging vehicle dynamics on the street on the way home has never worked for me.

Until i'm on track, and the tires are warm, the car's handling doesn't mean a thing to me.

just my $.02.

I didn't notice a difference in push that wasn't combatable with less front tire pressure.

Now the car, after robi, is fine.

x838nwy

You mean, a sort of partial roll cage? They tend to stiffen up the chassis and cause understeer. A quick fix would perhaps to stiffen the rear anti-roll bar to get some understeer back...

WarmPepsi

iTrader: (35)

yes, he put in an autopower rear bar, pickup points on the floor behind the drivers/pass seat, and the fender wells.

DRFTKNGG

iTrader: (8)

Common side effect of a roll cage is it can introduce understeer. You car has increased rigidity.
Adjust the rear sway bar to the stiffest setting. If you have an aftermarket front sway bar, I would change it back to the stock one.

What kind of suspenion?

nukblazi

The bar Robi installed is already at the stiffest setting...

A rollbar, a partial cage intended to prevent my melon from getting crushed in case I can't get the car straight before I enter a gravel pit next weekend

hmmmm- will check tire pressures... could the additional weight throw the rear alignment out of (Robi)spec?

CO_VR4

iTrader: (83)

Any significant change in stiffness in the front or rear will have corresponding effects on the car's handling. By adding the additional stiffness of the partial cage, you've changed the balance of the car. Robi mentioned to me that just adding a rear strut tower bar (or for that matter, changing the kind of rear strut tower bar or adding triangulation or a trunk cage) can and does affect the understeer. If you have a rear strut bar, you might take it out and see what that does to your overall handling. In real world terms, sometimes you can have a unibody that is "too stiff", when you're using off the shelf, non-racecar components in the suspension.

I doubt that it has affected the alignment, unless you tweaked the entire unibody when installing the rollcage. What it has done is stiffened the unibody in a different location, preventing it from flexing in the same way it did previously.

nothere

iTrader: (23)

COVR4 has some good points.

just be sure the change observed wasn't a fluke caused by road conditions.

nukblazi

It's not a fluke. I took it out for a spin on the roads I know around here yesterday, changed the tire pressure, and repeated. It's a stock suspension less the rear bushings and rear sway bar, no rear strut bar.

I increased the front tire pressure which fixed the understeer. I was mostly curious if anyone removed the front strut tower bar or installed a lower subframe brace up front. Basically, a sanity check plus attempt to resolve. Tire pressure did it.

Thanks

555R

iTrader: (5)

sup man...
i havent gotten around to adding a cage to my ride yet
Im supposed to hit up watkins glen this coming weekend
you need to post up some pics of the roll bar
im curious if im going with autopower or not
i know cusco makes one with optional side bars

as for your issues
I love that a roll bar is considered an antisway bar by some...
no flames intended
however
you did increase rigidity on the rear half of the car
plus added a little weight and possibly raised the CoG of the car
im not sure why it would understeer though
i would figure a stiffer rear would oversteer slightly
as my car is setup
it rotates very well with my homegrown alignment methods
by which i found out are very simialr to Robi's techniques
man i learned alot about alignment with the crazy rich PCA guys
next time your in the area you better hit me up

Kwman

iTrader: (4)

More throttle...

555R

iTrader: (5)

haha