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Newer rear suspension?

Posted: Sun Oct 14, 2007 10:10 pm
by Ady8077
Hi all

Can the newer bent rear lower arms be fitted to a car that had straight? If so, how much more travel do they give to the rear suspension? Mine bottoms out over pot holes

Thanks Adrian

Posted: Sun Oct 14, 2007 10:39 pm
by norma
Tim says yes - can't remember how much extra travel it gives though.
I'm sure there's a few on here that have already done it - stylussprinter????

Long travel rear

Posted: Sun Oct 14, 2007 11:08 pm
by MattD
It gives an extra 2", or there abouts, but you'll need longer rear shox & spring to suit.

Rob has all the proper info.

Matt

Posted: Mon Oct 15, 2007 8:49 am
by Werner Van Loock
As far as I know the least you should do is to take the 180lbs springs from the front to the back and replace the fronts with 225 or 250 if you have the original 180-130 setup. This should give some improvement. And if that's not enough you can mount the concave arms with new shocks and springs, but that's a more expensive upgrade. And you still need to put the 250's in front as the concave arms are supplied with 180 springs. (i think)

I'm trying the first option. (cheaper one :wink: )

Posted: Mon Oct 15, 2007 1:02 pm
by drhunter
New springs made the world of difference to my car, which has the straight arms and had 180/130 springs.

I upgraded to 250 front and 200 rear - 1300 xflow engine, 16st driver

It has transformed the handling, not only in the ride quality but braking is improved, the wheels don't spin as much from a standing start and I can safely lower the car. Previously it had to sit as high as possible to stop it bottoming!

It cost me ~£220 for the springs and coil compressors and took a saturday morning to do!

Good luck!

Rear suspension travel

Posted: Mon Oct 15, 2007 3:29 pm
by MattD
I think the main point you've missed is that if the suspension "bottoms out" then the shox's are fully compressed & closed, effectively you have no rear suspension.

Simple mechanics, if the shox pistons are fully closed then the next action is to bend something, usually the straight lower arm.
No amount of harder springs can prevent this if the wheel takes a big hit like dropping into a pothole.

Hence the reason for Tim to develop the curved lower arms giving longer travel.

Matt

Posted: Mon Oct 15, 2007 7:16 pm
by Ady8077
Hi

Yes I've already put the 180 springs at the back, and it has made the ride smother, but pot holes still make it bottom

Adrian

Posted: Mon Oct 15, 2007 7:33 pm
by se7ensport
see post 6 on the following from me: http://www.clubstylus.be/phpBB2/viewtop ... 84&start=0

I personally think that concave rear arms are over rated.








:wink:

Posted: Mon Oct 15, 2007 10:23 pm
by Ady8077
Hi

sounds interesting, but if the new arms give an extra 2" of travel whilst retaining the same ride height, they must give a better ride, especially on our roads :lol:

Adrian

se7ensport wrote:see post 6 on the following from me: http://www.clubstylus.be/phpBB2/viewtop ... 84&start=0

I personally think that concave rear arms are over rated.

:wink:

Posted: Mon Oct 15, 2007 11:06 pm
by se7ensport
I don't believe that they actually give an additional 2inch of usable travel. As explained in my other post, you work out your closed length and optimum open length and that gives you the travel your shocks need. if your shocks can open further than this you will induce roll as the car will be capable of jacking up when cornering. the flatter a car stays while cornering the better, having additional travel beyond what is needed is not a good thing as the spring will always try to open to the maximum length the shock will allow it.

Posted: Mon Oct 15, 2007 11:46 pm
by Ady8077
Wont the bent arms mean the shocks are open more at normal ride height? i.e if your shocks are compressed 1" at idle then so will the longer ones? wont they allow the wheel to travel further into the wheel arch? Also mine is a live axle which i thought acted like an antiroll bar? I appreciate the longer shocks may induce slightly more roll, but wont this help keep the inside wheel on the road?

Dont really no much about suspension setup, only no my bum hurt after driving down a bump road :shock:

Adrian

Posted: Tue Oct 16, 2007 9:39 am
by Werner Van Loock
alex, how much can the shock extend when the car is idle?

se7ensport wrote:I don't believe that they actually give an additional 2inch of usable travel. As explained in my other post, you work out your closed length and optimum open length and that gives you the travel your shocks need. if your shocks can open further than this you will induce roll as the car will be capable of jacking up when cornering. the flatter a car stays while cornering the better, having additional travel beyond what is needed is not a good thing as the spring will always try to open to the maximum length the shock will allow it.

Posted: Tue Oct 16, 2007 3:35 pm
by alecmartin19
drhunter wrote:New springs made the world of difference to my car, which has the straight arms and had 180/130 springs.

I upgraded to 250 front and 200 rear - 1300 xflow engine, 16st driver

It has transformed the handling, not only in the ride quality but braking is improved, the wheels don't spin as much from a standing start and I can safely lower the car. Previously it had to sit as high as possible to stop it bottoming!

It cost me ~£220 for the springs and coil compressors and took a saturday morning to do!

Good luck!
How much did you pay for each spring then? i've got protech dampers on my car and i only paid £25 per spring when i went to 250 front and 225 rear about 4 months ago!

either you've got different shocks, really Gucci spring compressors or you paid far too much?

maybe i'm wrong!

Posted: Tue Oct 16, 2007 5:33 pm
by kevp
I paid £25 for each spring (250 lbs) inc VAT & P&P from http://www.merlinmotorsport.co.uk

Posted: Tue Oct 16, 2007 7:29 pm
by se7ensport
Werner Van Loock wrote:alex, how much can the shock extend when the car is idle?

se7ensport wrote:I don't believe that they actually give an additional 2inch of usable travel. As explained in my other post, you work out your closed length and optimum open length and that gives you the travel your shocks need. if your shocks can open further than this you will induce roll as the car will be capable of jacking up when cornering. the flatter a car stays while cornering the better, having additional travel beyond what is needed is not a good thing as the spring will always try to open to the maximum length the shock will allow it.

mine allows the wheels to move up in to the body as far as i want them to which is approx 2.5-3 inch travel at the wheel (anymore and they would rub on the body) my ride hight is 167 rear and 145 front, when I jack the car up they wheels drop approx 1inch. anymore travel than this is pointless unless you are running a high ride height.