What are peoples opininons on the protec alloy bodied coilovers? What adjustment do they have?

Just about to start the front end steering/brake/suspension upgrade on the dutton. Next problem is i'm not sure what spring rate to use at the front. Reading some info on Duttons it would appear its currently Spitfire coilovers at the front about 180lbs. The rear is still leaf spring at the moment somewhere around 95-115lbs. The car weighs in at about 650kg with 2.0 pinto.

A lot of the locosts and westfields seem to have much harder springs up front? Its being used for road use but will be doing some track days.

Any opinions?

Protech Shocks - excellent value for money, very light, adjustable platform and damping (one control for bump and rebound)

As for spring rates, ignore those westy's with silly high spring rates. The rates you have now are perhaps a touch soft, but not far off at all

Thanks

Dont know what options you get for the spring rates but I was thinking of upping the front to about 200lbs

Also whats the difference between 1.9ID and 2.25ID springs?

You can only really compare spring rates with other cars the same as yours as suspension design has a large effect on the actual spring rates you need to use. If you wanted to do a comparison with different cars then you'd need to work out the effective wheel spring rate which takes into account the angle the spring/damper is at, and where it is attached to the wishbone etc.

[Edited on 27/5/05 by ChrisGamlin]

Ive doen a spreadsheet that accepts inputs for all the various parameters and desired wheel frequency, (as per staniforth) and outputs required spring rate.

E mail me if you want a copy. I don't know how to get it hosted somewhere so all can see it?

Cheers

Fred WB

quote:

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Originally posted by pmc_3
Thanks

Dont know what options you get for the spring rates but I was thinking of upping the front to about 200lbs

Also whats the difference between 1.9ID and 2.25ID springs?

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ns dev ....

what spring rates are you using on yours
front and rear ????????????????????????

he he!

Don't know yet!!

Ball park start point is going to be 275 lb on the front and 160lb on the back.

I think the 275 lb fronts may be too hard though, especially when I get through SVA and add a front anti-roll bar.

I will get a few sets, they are only around £12 each from Rally design so I will get 160lb for the rears, which I am fairly confident will work, and get 225lb, 250lb and 275lb for the front and try them. It's cheaper the buy the lot and only pay once for the postage!

COOL

that the figures i had in mind maybe
180 rear as im a lardy chap and 275 front
as mines plus 4 so there,s a bit more of
everything
cheers for that

Im running 275 front and 160 rear and its not to bad , i have found that the rear sometimes bottoms out when two up but is fine on my own.
however i have stiffened the front dampers up to 5 clicks and now find i have ok turn in on slow corners and roundabouts etc but am starting to find that i get understeer on long fast corners .This worrys me a little as the temptation to lift off is sometimes there even though i know i shouldnt, would this be due to to soft rear springs or to soft dampers at rear?.I dont want to soften the front any more as it now seems ok on bumps etc.When softer i was getting some bump steer.
Paul

quote:

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Originally posted by NS Dev
he he!

Don't know yet!!

Ball park start point is going to be 275 lb on the front and 160lb on the back.

I think the 275 lb fronts may be too hard though, especially when I get through SVA and add a front anti-roll bar.

I will get a few sets, they are only around £12 each from Rally design so I will get 160lb for the rears, which I am fairly confident will work, and get 225lb, 250lb and 275lb for the front and try them. It's cheaper the buy the lot and only pay once for the postage!

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