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Coilover springs

Posted: Thu Jun 02, 2011 6:40 pm
by WEBER45
What is the best coil lb spring for the rear coilovers?
I want to lower the car, currently got a 12inch spring but do not know the lb till I remove them.

Re: Coilover springs

Posted: Fri Jul 22, 2011 8:55 am
by chrismahon
When I had a Bronze the rear height was always a source of irritation which improved with a full tank and stuff in the back. Changing the spring rate won't lower the car reliably. The height is set by the free length of the damper unit. The spring is set softest as standard but over bumps especially with a full tank you may get the wheel hitting the arch if you fitted a softer spring. Can't remember the setup at the back precisely but I think the damper mounting positions are fixed points and there is no way of making an adaptor bracket on the suspension arm to reduce the effective length. So how do Bronze owners reduce the rear ride height if it is possible? Presumably there is an alternative unit to the Spax G999 unit originally fitted?

Re: Coilover springs

Posted: Fri Jul 22, 2011 10:53 am
by Stuart
Yes Chris you can either fit a shorter height adjustable damper or use a short run-flat spring and new shorter spring to get the back lower.

Re: Coilover springs

Posted: Fri Jul 22, 2011 11:38 am
by Hans Efde
I am not a fan of a short shockdamper. Then the suspension stroke will be limited by the damper. This will cause a thumping noise, bad road holding (the contact of the wheel with the road is easily lost) and a damper that will quickly start to leak. It's best to have the height of the car determined by the spring and the stroke of the suspension limited by rubber blocks on the car. On the Metro the amount of down travel is limited by a rubber block on the rear subframe, The up travel should be limited by a rubber block on the car.

Re: Coilover springs

Posted: Fri Jul 22, 2011 5:12 pm
by Rich
I've got bumpstops fitted to my rear arms, plus there's another one on the coil over shaft. What I don't have is springs (or mounting brackets), any suggestions on poundage and free length? I have adjustable platforms.

Re: Coilover springs

Posted: Fri Jul 22, 2011 8:51 pm
by Geoff Butcher
I seem to remember posting elsewhere that I calculated the rate of my original rear springs to be 107lb/inch. Don't know the free length as I've never taken them off. Will those Spax dampers never wear out?

Re: Coilover springs

Posted: Sat Jul 23, 2011 12:38 pm
by rocketron
Would it be possible for someone to put the info regarding spring rates, shocks and their pros/cons and evaluations, all modifications for all models, somehow in one place on the forum, for those ,like myself, who have poor computer skills, to easily access. I know there can't be one set-up which will suit everyone tastes or needs: my convertible when it needs pumping up will NOT get up my drive, so lowered front end is no use to me. If it's 1/2 in. over will just bounce and spin it wheels!
It appears to me that a lot of really good work has been done on Midas suspensions by members and I'm impressed and appreciative of it, but I haven't the skills, nor the patience admittedly, to trawl the forums. I think it would be good to reconcile suspension information in one place.

The hydraspastic units on both my mk 3's are not good and going to need replacing very soon, but with what rate coil springs really worries me. A local mini young nut has fitted "road" rated coil and shocker conversion to his mini, from a well known mini specialist, and it is truly crap. Ok for a super smooth race circuit, but positively dangerous on roads: was way too stiff. This car was not as good as any of my rally minis.Makes me wonder how bad the "rally" rated coils are.
Please Help!!!

Re: Coilover springs

Posted: Sat Jul 23, 2011 4:35 pm
by MrBounce
I agree completely with Rocketron. I have springs and dampers on the back of my Mk1 and am likely to need to replace them at some point during the rebuild. I have no idea what i should be replacing them with. Mini coilover coversions seem ridiculously expensive. I have not had a close look as yet as I'm concentrating on stripping the interior and dash at present but if the springs are ok is it just a standard damper inside? I've no idea!! :o

Re: Coilover springs

Posted: Sat Jul 23, 2011 7:53 pm
by wolfie
On my gold I've fitted 90lb but I like a 'sporty' ride. Before coilovers I had modified the hydrospastic units to lower them and stiffen them up. If you're not sure then try Faulkener springs as they start at 80lb for about £20 a side then work your way up

Re: Coilover springs

Posted: Mon Jul 25, 2011 2:23 pm
by chrismahon
Hans has a point. My Bronze used to hammer over bumps with no weight in because the suspension dampers were always nearly fully extended. The Gold had exactly the same Spax units and the same springs but the suspension sat at a mid point due to the additional rear weight. So if the back was heavier on the Bronze or alternatively, as Stuart said, a short run flat spring and a shorter main spring of the same original poundage should do it. The neural point will then be with the damper at mid position. The run flat spring won't force the damper open so hard over bumps so they should last a lot longer.