Coilover Springs

[Guest robinj66]

I have an S7 with Sierra rear axle. I want to change the rear suspension to coilovers. best way i can see of doing this is as per my mate's S III. Hopefully there is a picture attached.

 

I have some GAZ adjustable dampers with open length 16" and closed length 10.5". I need to buy some springs to fit.

 

How long should the springs be and what sort of poundage should they be? Best I can tell from trawling through threads here & elsewhere is that a starting point should be around the open length of the dampers but 16" seems a bit long to me (and Rally Design don't list them for 1.9" diameter in heavier rated springs).

 

Ref the rate of the springs, I am fitting a V6 Cologne engine which is heavier than the usual Pinto - will this affect the spring ratings on the rear?

 

Does anyone have info on the design weights for the stainless S7? {I will need this info for the SVA in due course}

 

I appreciate that tis is a subject that some will feel has been done to death but reading through numerous posts on RHOCAR & Locostbuilders has left me more confused than when I started

[Guest turbo]

fit the damper to the car and jack it to the height you want to run then measure between the seating area of the spring and then add about 1" of spring for compression once the cars load is on.

i would estimate about a 300lb spring but this can be trial and error due to your opinion of ride or handling.

[Grim]

i would estimate about a 300lb spring but this can be trial and error due to your opinion of ride or handling.

 

Probably less than that, it's lighter than a 2b. Someone who has that car and has done it will pipe up with a value soon

[Guest turbo]

what is the weight difference

[Guest Alex Spratt]

I have an S7 with Sierra rear axle. I want to change the rear suspension to coilovers. best way i can see of doing this is as per my mate's S III. Hopefully there is a picture attached.

What rating spring does your mate have on his car, also whats the open and closed lenghts of his shocks?

I asked a very simular question last week, so keep us up to date with what u find.

cheers

Alex

[Guest robinj66]

what is the weight difference

 

 

I don't know. I have asked Robin hood to provide me with the design weights for the stainless S7 (Sierra front subframe) but I wonder whether they will still have that information due to the changes of ownership and the time elapsed.

 

If there are any S7 owners out there who have put their car through SVA, can they let me knw what they put on the SVA forms.

 

What rating spring does your mate have on his car, .....

I asked a very simular question last week, so keep us up to date with what u find.

cheers

Alex

 

Unfortunately this is another unknown. He bought the kit secondhand. Since the chassis are similar (SIII & S7) I took the measurement of the damper from his car and roughly checked it against mine (which currently has the standard Sierra springs & separate dampers fitted) - hence I obtained shockers to give me a nominal 13" length ( 10.5" - 16")

[Grim]

what is the weight difference

 

It's probably no more than 100kg lighter overall, a search on here will give you a more accurate answer.

[Guest timswait]

Probably less than that, it's lighter than a 2b

But the engine's heavier, probably still a bit lighter overall though. 250lb-300lb should be the range you want to look at.

Give Rally Design a ring, they sometimes do (or can get in) springs which aren't listed on their site, I got some for mine like this.

[Longboarder]

You should try to fit the damper so that at normal load (wet + one person) ride height the damper is about two thirds extended. This allows for one third extension two thirds compression. The angle of the damper at this height should not be vertical as shown in your picture but the top should be slightly forward. The damper should be positioned so that in the last inch of compression it should be at right angles to a line drawn from the trailing arm pivot point to the damper lower eye. This will give you slight rising rate damping. I have 300lb/inch springs on my 111 but my dampers fix into the spring pan centres. The damper fixing you intend using is further away from the pivot point so softer springs will give the same effect. I would guess 200lb/inch.

 

Nigel

[Grim]

true, didn't spot the cologne bit....