Tuning Coilovers or chassis strengthening???

[Sweex]

Good evening!
Im finding that even though I've lowered my car with h&r cup suspension (50mm front, 40mm rear) with uprated h&r shocks it still seems to have a lot of body roll, it handles well but i want to try and get rid of some of the roll.

I watched my friend drive my car around a small corner and you could see the car lean! Ive seen some cars on coilovers that are completely flat through corners, whereas mine is not! The roll bugs me... the fact my girlfriends mk2b standard height sporting has less roll than mine is saying something!
Its much more fun to drive in the corners!

What would peoples advice be? Should i swap for some coilovers to get better handling (looking at h&r coilovers/blisteins/weitecs) or go for chassis?
Strut braces, forge underbody braces?

Any opinons etc appreciated.

 

[fingers99]

It's a Punto GP -- it's supposed to be a soft, supple car for people who'd like to own a Maserati.

But:

Chassis stiffening wont reduce roll unless the roll is caused by chassis flex (extremely unlikely unless you're running slicks).

Coilovers don't do anything useful on road cars that uprated shocks won't do. All they are is shocks with height adjustment and an easy choice of spring change.

Most modern Italian cars will roll a lot -- roll isn't necessarily a bad thing or condusive to bad handling unless it results in lack of grip.

The correct way to counter roll is by stiffer anti-roll bars. Keep the same ratio front to rear and you'll retain the handling balance. Alternatively, thicker front increases understeer, thicker rear reduces it.

 

[Sweex]

It's a Punto GP -- it's supposed to be a soft, supple car for people who'd like to own a Maserati.

But:

Chassis stiffening wont reduce roll unless the roll is caused by chassis flex (extremely unlikely unless you're running slicks).

Coilovers don't do anything useful on road cars that uprated shocks won't do. All they are is shocks with height adjustment and an easy choice of spring change.

Most modern Italian cars will roll a lot -- roll isn't necessarily a bad thing or condusive to bad handling unless it results in lack of grip.

The correct way to counter roll is by stiffer anti-roll bars. Keep the same ratio front to rear and you'll retain the handling balance. Alternatively, thicker front increases understeer, thicker rear reduces it.

Ok, thanks a lot for your advice, it all makes sense.

I thought about coilovers, they are stiffer shocks than the h&r ones so therefore should reduce bodyroll a bit more?? And being able to adjust the height should make it handle a bit better too?

Like I said, the handling isn't bad, it grips well and i can chuck it into corners but i just dislike the body roll.
I take it, i would have to go custom with the ARB's?

Many thanks.

 

[fingers99]

They'll reduce body roll (but so would stiffer springs). I think lowering much more than you have will create problems with ground clearance.

The biggest issue with coil overs is that, because they're parallel wound they have no means of countering the effect of stutter bumps or braking loads (both of which will try to cause the damper to seize by -- temporarily we hope! -- bending the strut. And then they seize the adjusters. The other issue with stiffening the suspension is that it tends to decrease grip as the car merrily bounces from bump to bump. It's for this reason that modern performance cars -- the trend was pretty much introduced by Colin Chapman -- tend to have soft springs and stiff dampers.

Stiffening the ARBs is the "proper" way to go. I mean, they're called Anti Roll Bars!

Staniforth's book Competition Car Suspension is well worth a read. What your mates or Fast Car tell you generally comes out of the rear end of a horse!

 

[Sweex]

I'm not really looking at lowering the car much more, i have no problems with ground clearance currently so I wouldn't want to go much lower really.

What you mentioned about stiffer dampers and softer springs is something i am looking for, i want the ride stiffer than what it is to help reduce body roll, i did my research on the kit i bought and it seemed pretty good but they have since changed them to 'comfort' suspension.

Haha yeah i guess, i'll have to look into stiffer arbs, maybe the bushes are the first place to start?

Thanks.

 

[Sweex]

Any other input from anyone? Where to get stiffer/larger arbs?
Whether to just go for bushes or get coilovers as well?

 

[MrMurray20]

Isn't that what the under body braces do? Replace the arts. SJB1985

 

[middo85]

I was impressed with how little body roll i had after fitting Eibach sportlines to stock shocks, would have thought coilovers dropped that much would have a similar effect.

 

[Sweex]

Isn't that what the under body braces do? Replace the arts. SJB1985

Just meant to tighten the front end up, not sure about the body roll? May not fit on mine with the new exhaust lol!

 

[fingers99]

Isn't that what the under body braces do? Replace the arts. SJB1985

Replace the arts? All the poets will protest!

They don't replace ARBs.

Body stiffening will only affect suspension in so far as the more rigid the body, the better platform the suspension has to act on. But, crush zones aside, modern chassis are pretty rigid, to the point where you'd suspect that anyone who can feel the difference between a braced and unbraced body on the road is trying far, far, too hard.

F1 cars probably have the most rigid bodies out there, but all, AFAIK, still use ARBs at at least one end.

 

[SJB1985]

Isn't that what the under body braces do? Replace the arts. SJB1985

I have Eibach sportlines, 20mm Hubcentric spacers twin forge under body braces and my GP has very minimal body roll. I put this down to under body braces. I cannot tell people to buy or not. All I can do is give my opinion from my experiance with my car. I would however, highly recommend them.

 

[ChrisUK]

Me too. Not sure if mine had less body roll but it's defo more positive in the corners and less like a sponge cake.

 

[Sweex]

Me too. Not sure if mine had less body roll but it's defo more positive in the corners and less like a sponge cake.

I may be getting them for christmas so will see haha.

 

[chimera gunner]

http://www.txautosport.co.uk/fiat-punto-rear-adjustable-anti-roll-bar-497-p.asp

Might be worth a look?

 

[Sweex]

http://www.txautosport.co.uk/fiat-punto-rear-adjustable-anti-roll-bar-497-p.asp

Might be worth a look?

Thats a really good shout dude, good find! Might have to part with my money as well as the subframe braces

 

[chimera gunner]

No worries. I've got the subframe braces and can feel a difference, even though my shocks are knackered!