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Will stronger springs stop body roll?
Antnicuk - 21/10/08 at 07:48 PM

I have put heavier springs in the stylus but still get lots of body roll. I have a front anti roll bar and a live axle. I'm not sure what the springs are on the front but i think they are around 250 - 300, the rears are now 250 and ride really well. I have a fair bit of power and a lack of traction on the back but i would like to try and stop some of the roll. I didnt realise how much until i saw the pictures of the track day as it didnt feel that much on track.

I'm estimating the weight at abouut 650 - 680 kg and usually have 2 people in it. In the piccy below there is about 28 stone worth. I weigh 13 stone.

Should i tru even heavier springs? or set the shocks to a harder setting?, i am about 8/20 on the rear and 12/20 on the front.

Any ideas?


Mark G - 21/10/08 at 07:59 PM

Springs won't stop body roll, just limit the amount the suspension moves with a certain amount of force.

If you say that the car handles and feels ok on the track I'd just leave it. Who cares if it looks like you have a bit of roll, all cars do.


tomgregory2000 - 21/10/08 at 08:00 PM

thicker anti roll bar maybe

stronger springs will upset the ride, it will make it bouncy over uneven surfaces and no fun to drive down country lanes, this is what i found on my corrado


Canada EH! - 21/10/08 at 08:02 PM

I think a larger front swaybar is in order, stop some roll and maybe a little understeer to correct the massive oversteer.


Antnicuk - 21/10/08 at 08:29 PM

most of the oversteer is caused by my right foot and 330ftlbs

The new rear springs are not bouncy at all, far from it, so i could go a little firmer without sacrificing ride.

Would increasing the shock firmness reduce body roll?,

The roll bar is already about 17mm tube with a wall thickness of about 4-5 mm.


Echidna - 21/10/08 at 08:43 PM

quote:
Would increasing the shock firmness reduce body roll?,

The roll bar is already about 17mm tube with a wall thickness of about 4-5 mm.


Rebound damping does not affect the total roll but how fast you achieve total roll angle!
Bump damping controls the unsprung weight of the vehicle, the upward movement of the suspension.
Damping will not affect the total roll!

[Edited on 21/10/08 by Echidna]


stevebubs - 21/10/08 at 09:29 PM

Hop onto the Sylva-Chat list. There's a couple of Stylus experts on there who will help you with setup.

http://groups.google.co.uk/group/Sylva-Chat?hl=en-GB


hobbsy - 21/10/08 at 09:36 PM

quote:
Rebound damping does not affect the total roll but how fast you achieve total roll angle!
Bump damping controls the unsprung weight of the vehicle, the upward movement of the suspension.


Is that not the other way around?!?


Liam - 21/10/08 at 10:42 PM

If you normally have an 'extra' 180kg sitting right in front of the rear axle, that's very significant and needs to be taken into account designing the suspension. If you calculated your wheel rates/frequencies using the full running weight (inc driver, passenger, fuel) you might find you're much lower at the rear than the front due to all that weight, when you ought to be higher.

For such a rear weight bias you probably want stronger rear springs, and might consider a rear anti roll bar, and even thicker rear tyres. That ought to even things up a bit.

All imho of course.

Liam


General Bilko - 22/10/08 at 11:32 AM

But just to confuse the issue....Locost racers spring rates (usually) would be set up higher at the front and lower at the rear!! Say 350-400# front & 100-150# rear. Lack of traction might be a result of too high spring rate at the rear - you aren't getting enough weight transfer under accelaration and the wheels just spin? But racers don't (normally) have a passenger.....


Antnicuk - 22/10/08 at 07:21 PM

thanks guys. I know what you mean about too hard springs on the back will be bad for traction but it seems to squat a lot under power so i assume i they are not too hard at the moment.

350 - 400 on a lightweight 7 racer is very hard. I will have to try some

Without anybody in the car it sits higher at the back by 15mm measured at the seat pan and the front cross brace, but with 2 people and a squirt of power it soons gets lower.




:{THC}:YosamiteSam - 23/10/08 at 07:40 AM

you could move the roll bar clamp points if possible? - the roll bar should have two arms on it - by moving the closer to the corner it will become stiffer - roll bars work by twisting - the bar resists this so by moving the clamping point it makes it harder to twist... if there is provision to do so


Antnicuk - 23/10/08 at 12:09 PM

there is but i'm at maximum stiffness, ie, the clamps are as close to the bend as i can get them.

where can i get a roll bar made. I could easily mount the same thickness in its place but using a solid one would be a little stiffer?.