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Shocks & Springs on Fury
Jos Fury - 15/9/08 at 08:25 AM

I want to replace my old Spax on my Fury.
They are 12". I also want to change the springs.
GAZ ? Spax ? Protech ? Prices ?
Weight of the car is 560kg. Was thinking about 180 lbs rear and 220 front for the springs ?
Difficult choice I believe...
Regards
Jos


maskell01 - 15/9/08 at 08:42 AM

What will you be doing with the old spax suspention?


jimgiblett - 15/9/08 at 08:47 AM

I purchased Protechs and have been very happy with both the quality of the product and the supplier. They are alloy bodied and significantly lighter and dont rust like the Spax units. I think I paid £330 for a set which I collected in person but that was a while back. Gaz certainly seem to be priced keenly but I have heard various reports on the quality.

Avos are another alternative as are Nitrons if you are feeling flush.

Faulkner springs are a quality spring manufacturer but as far as the spring rates this will be a matter of personal choice and the type of use.

Just my opinion obviously.

- Jim


mr henderson - 15/9/08 at 10:21 AM

First thing is- do you want the springs to be narder or softer than what you have now (otherwise, or course, you wouldn't be changing them)

2nd What is the rate of the existing springs. You can measure it with a bathroom scales if you are careful, see what the scales show after say half an inch compression (Hookes Law)

3rd. If you are changing the spring rates you will also need to change the unfitted length if you want the ride height to stay the same, unless you can make up the difference by adjusting the lower spring pans (But you won't want to restrict your suspension movement too much, so changing the unfitted length will usually be better)

John


Jos Fury - 15/9/08 at 04:00 PM

thanx for your advice so far.
The springs which are fitted now are too long it seems. Last week I removed the shocks to check the unsprung length of the springs and the length of the shocks. I found out the springs have to be compressed a lot ( even with the lower spring pans in lowest position ) to fit everything again. Dampers are 13 inch now and springs 9 inch. Springs are 9mm in dia ( rear ) and 10mm front. Do not know the rates as they were fitted already when I bought the car three years ago. Pitty !
Even with the shock absorbers set at the softest the ride is not soft enough for me.
( Due to the high precompression of the springs needed to make them fit ).
Have decided to go for 8 inch springs 180 lbs rear / 220 front and see what happens. I also got two 8 inch springs 160 lbs. This should be a good start I believe.
The ride height at the rear is to low now but when I increase this the rear will become harder again.
Will fit springs etc. maybe next week and put the car on weighing scales too.


mr henderson - 15/9/08 at 04:04 PM

quote:
Originally posted by Jos Fury
Do not know the rates as they were fitted already when I bought the car three years ago.


So measure the rates!!!

Don't guess, even if you can afford to try umpteen different springs you will still have the hassle of changing them. Don't miss this opportunity to give your spring slection a flying start.

John


mr henderson - 15/9/08 at 04:12 PM

quote:
Originally posted by Jos Fury
Even with the shock absorbers set at the softest the ride is not soft enough for me.
( Due to the high precompression of the springs needed to make them fit ).



If the springs needed a lot of preloading then they will be SOFT springs. The preloading was needed to get the soft springs under enough compression to resist the downward movement of the car (due to its weight)

For instance- 12" spring 100lb/in would need to be compressed 4 inches to resist a 400lb load.

A 10" 200lb/in spring would only need to be compressed 2 inches to resist a 400lb load.

The first spring would be a much softer spring than the second one because if the wheel hit a bump and the resultant upward force was 100lb, it would move 1 inch, whereas the second spring would only move 1/2 inch

These numbers are only examples, and assume that the springs are vertical and in line with the wheels (which they won't be in your car)

John


Fred W B - 15/9/08 at 06:37 PM

See rate thread here

Cheers

Fred W B


adithorp - 15/9/08 at 09:15 PM

I've got Gaz Gold shocks on mine. No problems so far (only 200 miles so far).
I've got 210lbs front and 160lbs rear. I'm considering softer springs at the front though as I'm getting some understeer and the shocks are fully wound off.

Winding your spring seats up to lift the rear won't increase the stiffness. The spring rate doesn't alter.

adrian


procomp - 16/9/08 at 06:58 AM

Hi

The thing to remember with the dampers on the Fury's at the front is that just ordering off the shelf valved units doesn't work if you have the inboard damper setup with a top rocker arm. You need to take into account the fact that they are more direct acting than a std type damper being used outboard at an angle.
So you need to pay attention to the valving ratios and the working poundage of the damper. Other wise you'll end up running it fully soft and still not able to get the damper into the working range.

Not too mention they are also sat behind a radiator.

Cheers Matt


Jos Fury - 16/9/08 at 02:45 PM

Thanx again. I am still reading ... Learned a lot already

[Edited on 16/9/08 by Jos Fury]


hobbsy - 17/9/08 at 04:59 PM

I recently had my suspension set up my Matt and Ivan at Procomp.

If it helps I'm running 180lb springs at the front and 130lb at the rear. But mine is a BEC so its a bit lighter than yours.

I kept the original Spax as they still work ok (well mostly )

Had them dyno'ed and balanced by Procomp and along with the setup and corner weighting etc its made a massive difference.

Probably the best money I've spent on the car so far.


Jos Fury - 1/10/08 at 06:34 PM

Thanks for your advice.
I am now running GAZ dampers with 180 springs rear and 225 front. Still fiddeling around with the damper settings / tyre pressure etc. Hoping for some dry conditions to make some more test kilometers. Untill now I am satisfied with the setup.
We have corner weighted the car, which makes quite some difference to offcourse. Before it was cornerweigted there was a difference of 25Kg on the front .Total weight incl. 30 ltrs petrol, softtop, tools 612 Kg. ( Without me in it )
cheers
Jos