roll centre???

[wil_rolla]

hi all,

i'm going to lower my car in the next week or so (only 30-35mm), and lately iv been hearing that lowering your car changes the "roll centre" and this can make your car handle worse then before..

this is what i'v been hearing:

lowering car = lower centre of gravity

lower centre of gravity = lower roll centre

lower roll centre = more body roll

is the roll centre adjustable?

when you get your lowered at a proper work shop will they deal with this???

abit off the topic but whats the bad points of compressed/reseting standered suspension to make them lower?

thanks wil

Edited May 14, 2008 by wil_rolla

[qkslvr]

Roll center is just a point in space relative to your car where, if you draw some imaginary lines from certain suspension components, the lines meet. In racing terms it just helps you figure out where the weight will transfer during cornering which then helps you figure out spring rates, antiroll bar sizes, this then dictates your bump damping and rebound damping settings.

To everyone else who just wants a lowered car for looks.... it doesn't mean much. you've already sacraficed your ride quality with those low profile tyres and coil over setup anyway. hehehe

P.S you want your roll center close to your center of gravity.

Edited May 14, 2008 by qkslvr

[SuperDave]

is the roll centre adjustable?

when you get your lowered at a proper work shop will they deal with this???

abit off the topic but whats the bad points of compressed/reseting standered suspension to make them lower?

There is very little need to be worried about the roll centre change as there is very little you can do about it. Plus it is a dynamic thing that one can never fully control.

A proper workshop won't bother doing anything about it unless they build proper race cars, and even then you have to ask for it to be done and be aware it wont be cheap.

As for the reset spring question a better way of wording it would be, "Is there any benefits other than cost for resetting springs?". Hopefully that answers that question for you ;)

The roll centre ideally should be as qkslvr said, raising the roll centre may reduce the amount of body roll. However, you need to be thinking of the other effect this will introduce by raising the roll centre, and that is the effect of jacking and the gaining of positive camber on the loaded wheel. The original VW Beetle was prone to this under hard cornering. So generally you trade off the body roll to avoid jacking.

[SILVABULLIT]

wouldn't bother restting the stock springs. someone on here bought a sportivo with them done and it rides badly and has "issues" with spring bind.

[CHA54]

roll center adjusters space the suspension arm down from the hub to get the suspension geometry back to normal in comparison to the chassis when the car is lowered. It's usually only the guys serious about suspension that will go to this extent.

It is possible to fabricate a RCA for the front of the FWD rolla's, if you track the car then you will notice a good difference with the RCA in place on a lowered car.

Some reading can be found here: http://suspensionparts.info/showthread.php?t=999

And an example of an RCA as used on Honda's: http://www.jsracing-net.com/catalog/produc...at=4&page=1

Edited May 15, 2008 by rollamods

[wil_rolla]

thanks for the reply's guy's

it's nice to know that some people actuly know what they are talking about...

i'm hopeing to see a few track days with my car but i'm not entering race comp's..

did any of you guy's lower your car with this in mind??

and should i just lower the car and not worries too much about the 'roll centre'

sorry for all the noobness but i just want to do things right the firist time round.

thanks again