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Author: Subject: spring rate
gy351100

posted on 6/7/07 at 10:03 AM Reply With Quote
spring rate

hi all

which is the better option

1 stiff spring rate/soft shocker setting

2 soft spring rate / stiff shocker setting

or what

cheers

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nitram38

posted on 6/7/07 at 10:13 AM Reply With Quote
Your spring rates should be matched to the weight of the car plus the load and a bit more for some anti-dive. This will take some calculations.
You can weigh the front of the car, divide it by 2 and add a load weight plus a bit more for anti-dive. This is repeated for the rear, but at the end of the day is a preferencial thing.
Shock rates, you should start off soft and gradually increase the rates until you are happy with the ride.
If your springs are too soft, you will get excessive dive and your brakes will feel softer under foot. Hard springs will produce little dive but your brakes will feel solid. You are looking for a compromise.
With shocks, if set too soft, your wheels will bounce too much and lose traction over bumps. Too hard and you will feel every bump.
Everything is down to your own driving style and there is no easy answer.
You will have to be guilded by other people's setups and work from there.
I don't have a 7 but my advise is to go for adjustable shocks so at least one componant can be kept, but you may well find that you have to change springs to find the optimum setup. At least these are relatively cheap at around £25 per pair.






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thunderace

posted on 6/7/07 at 11:26 AM Reply With Quote
http://www.andersensmith.freeserve.co.uk/suspension.htm

this may help..

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Ivan

posted on 6/7/07 at 11:32 AM Reply With Quote
There are scientific ways of calculating the spring rates required as per Allan Staniforth et al. However it seems that most people end up with springs 50% or more stiffer than what one would expect doing the calculations.

My personal feeling is that the very strong springs used by most is more due to improper selection of shock length and mounting bracket location giving insufficient wheel movement before bottoming of the shock hence the need for strong springs.

The consequence of this is a harsh ride with questionable and possibly unpredictable handling- especially on bumpy roads.

So the short answer is spring selection depends on many things such as ride height, wheel travel available, mounting bracket layout, shock length etc etc so for home built cars suck it and see.

Remeber the softest spring that you can get away with with the minimum amount of bottoming is the best. Particularly on a road car.






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ChrisGamlin

posted on 6/7/07 at 12:33 PM Reply With Quote
From what I understand......

1 stiff spring rate/soft shocker setting - will give you a very bouncy ride because the damper cannot damp the oscillation of the spring, so if you hit a bump it may take two or three oscillations before the car is stable again, and when cornering it may bounce a bit on turn-in before settling into the turn

2 soft spring rate / stiff shocker setting - will mean slow wheel response so hitting bumps etc that need high wheelrate, it may knock you off line as the wheel cannot travel (vertically) fast enough to keep in contact with the changing road surface. It could also mean the car gradually leans more in long sweeping corners than short corners because the outside suspension will gradually sag with little resistance from the spring to keep the car level.






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turbodisplay

posted on 6/7/07 at 05:45 PM Reply With Quote
Pedantic mode on:
Chris, at 45 degrees the spring rate will be 70%.



Pedantic mode off:

Darren

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