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abarth squadra storica forum

abarth cars - community => 1000 tc , radiale , replika => Topic started by: Martini Gasolini on February 13, 2007, 02:00:48 PM

Title: Coilovers
Post by: Martini Gasolini on February 13, 2007, 02:00:48 PM
Hi Folks!!

I wonder if anyone knows,I am in progress building coilovers on my fiat 850 and on my brothers Nurnberg ring 600 Replica.
Does someone know what springrate to be used in the rear coilovers?
I will be using GAZ shocks,cause they can be ordered in in all lenghts,with all kind of fittings.(stem or eye fitting,or even with uniballs)
In the front i use 9"long springs with 275 lbs springrate.works superb!

Thanks!

Martini Gasolini
Title: Re: Coilovers
Post by: ChrisD on February 14, 2007, 08:48:07 AM
I think SPAX has a front coilover kit for the 600
Title: Re: Coilovers
Post by: Pantdino on February 15, 2007, 06:04:17 AM
Martini,

The spring rates for a car have to be looked at as a system--so the rear rate you want is determined by the rate you are using in the front.  If you make the rear too soft in comparison to the front for the amount of weight on it, the car will understeer.  If you make them too stiff, it will oversteer.

I believe the rate is proportional to the amount of weight on that end of the car--for example, if the car has 60% of its weight on the rear and 40% on the front, the rear springs should have a rate 1.5x the front.  At least that's what the spring and shock manufacturer I was talking to got from his formula.

So the spring rate for your rear will be  275 x weight on rear axle / weight on front axle

Jim Oddie
Title: Re: Coilovers
Post by: Martini Gasolini on February 15, 2007, 02:17:28 PM
Thanks Jim!
So i might be looking at 400 lbs for a start then?
I found this rather interesting calculator for finding weight %.
My 850 is 650 kg total.240 kg in front,410kg  in the rear.
I ended up on 63,07% front/rear balance.
Hm,could be better!

Martini Gasolini
Title: Re: Coilovers
Post by: Pantdino on February 16, 2007, 07:24:12 AM
I looked up some information I got when I was looking at springs for my Pantera and found that the angle of the spring in relation to vertical also affects the spring rate you want. 
Is the rear spring at about the same angle from vertical as the front spring on your car?   If they are about the same, then I get

410 / 240 x 275= 469 lb spring. 


Jim
Title: Guy is in the hospital
Post by: Pantdino on February 18, 2007, 08:19:29 AM
I just happened to see the banner that Guy has gone into the hospital for a hip replacement.  I had noticed that he limped when he walked, and now I know why.
Guy, we all wish you the very best for your surgery and recovery!

Jim Oddie
Title: Re: Coilovers
Post by: guy moerenhout on February 19, 2007, 10:04:50 AM
many thanks Jim,I am back home but still have to be calme and not walk  for one week .After this I hope to attack back all my work and opening off new place
Title: Re: Coilovers
Post by: Pantdino on February 20, 2007, 06:03:07 AM
I'm glad to hear everything went well! 

And congratulations on your new place.  This will be THE center for Abarth activity!

Jim
Title: Re: Coilovers
Post by: Paul vander Heyden on April 08, 2007, 05:07:43 AM
Hello Martini

What you really need to know is the wheel rate.  This is determined by the location of the lower mounting point of the shock.

On my 1000TC  I have 250 lb coils in the front and 350 lb coils in the rear.  I run 20 position adjustable shocks both front and rear.

I have just released the independent front suspension for the Fiat 850 type chassis.  Similar to the Scorpione one.

Hope this helps

Regards,

Paul Vanderheijden
www.scuderiatopolino.com
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