Spring rates
Author
Discussion

jackh707

Original Poster:

2,132 posts

185 months

Tuesday 8th January 2013
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Finally getting round to ordering some new suspension but having great difficulty finding spring rates. Car is 570kg ready to go. Road and track use, mostly 1 up, occasionally 2 up.

My best research is suggesting 225lb front 150lb rear.

Any help, or spring rate suggestions please.

SimonRogers

146 posts

187 months

Tuesday 8th January 2013
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From your description of your main use and not knowing the power and engine spec I would suggest these rates are to stiff. Particularly for road use.

If you can tell us engine and chassis spec I could advise more accurately.

However more important is that without knowing the dampers that the springs are to be matched with the spring rates are a little irrelevant.

Please feel free to email if you wish. simonrogers7@gmail.com

jackh707

Original Poster:

2,132 posts

185 months

Tuesday 8th January 2013
quotequote all
Apologies...

It is a 1991 de dion S3 supersprint (long cockpit)
1.8 zetec, somewhere around 160hp using 14inch wheels

Looking at using GAZ shocks, but may be tempted elsewhere for a not too massive increase in price, really want to keep it under £500.

My figures are as good as plucked out of thin air, myself and the other person who will drive it are both around 90-100kg.

SimonRogers

146 posts

187 months

Tuesday 8th January 2013
quotequote all
Jack - Thats fine no need to apologise.

With relatively heavy engine like the Zetec and relatively heavy drivers rolleyes and the weaker valved set up Gaz I guess you are about right with 225 and 150 - It is likely to be a bit bouncy and stiff though.

I would prefer to specify a stiffer stronger damper and springs down to 200 and rear 130. The best set up is progressive though but this can cost a fair bit more.

Afraid I do not do any dampers under £500. AVO come close but still more.

jackh707

Original Poster:

2,132 posts

185 months

Wednesday 9th January 2013
quotequote all
Cheers, that's helpful information smile. When you say weaker valved, is it really relevant if they are adjustable, or am I missing something, I don't know a lot about suspension.

The current shocks, while reasonably competent on a smooth road, proved soft and wollowy around fast sweepers on track with a fair bit of body roll, and get in a mess when going over undulations on roads at 60mph+. Traction is always ok, but there is a fair bit of weight transfer under hard acceleration.

Then at low speed over bumps and ripples, it's crashy.

The current front suspension is original, and the rears are a reconditioned set of spax (I think) off ebay for £50, which are equally old by my reckoning.

pikeyboy

2,349 posts

243 months

Wednesday 9th January 2013
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SimonRogers said:
Jack - Thats fine no need to apologise.

With relatively heavy engine like the Zetec and relatively heavy drivers rolleyes and the weaker valved set up Gaz I guess you are about right with 225 and 150 - It is likely to be a bit bouncy and stiff though.

I would prefer to specify a stiffer stronger damper and springs down to 200 and rear 130. The best set up is progressive though but this can cost a fair bit more.

Afraid I do not do any dampers under £500. AVO come close but still more.
Lightly sprung and highly damped, wink

SimonRogers

146 posts

187 months

Wednesday 9th January 2013
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Jack - call me 07920 843146

czechmichal

48 posts

188 months

Friday 11th January 2013
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Hi,
I´m dealing with the same problem.
I got 2009 Roadsport 175 SV, the weight should be about 600kg ready to go and i got 90kg.
I would like to upgrade from the standart suspension to Nitron R1 or something similar. I drive track/road almost 50:50, but i can live with some compromise on the road to get the best on trackdays.
For the road i will use 14´´ wheels and for the track 13´´ with CR500 (maybe ZZR next year).
What springrates do you recommend?
Thanks a lot guys

SimonRogers

146 posts

187 months

Friday 11th January 2013
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As above - call me 07920 843146 or see me at Autosport over the weekend on SBD stand 8315 Hall 8

jackh707

Original Poster:

2,132 posts

185 months

Friday 11th January 2013
quotequote all
SimonRogers said:
As above - call me 07920 843146 or see me at Autosport over the weekend on SBD stand 8315 Hall 8
I might see you at the stand tomorrow....