strathconaman

I use my C4S as a daily driver and weekend touring car. Up here in the Great White North, the roads are total crap. I am exploring the idea of putting C4 springs on it before I have to get a spinal fusion.

I can't find spring rates, or lengths for the 2002 C4 or C4s. According to the "essential guide" the 4S is only 20 lbs heavier than the C4.

What would the result be if I put stock C4 springs on my C4S? Can it even be done?

OKB

c4s has different sport springs special to its model. Dont mix up different cars and different springs, they werent made to do that. If you want a soft ride keep your old worn out springs and shocks.

strathconaman

I am not asking if I should, or should not. I am asking what the results would be.

dporto

Seeing as how all the aftermarket suspension kits are marked for C4/C4S/Turbo, I'd think that the spring rates are very similar between these models - I don't think a 20 lb weight difference spread across two axles is going to be noticeable. I think a fat guy/girl in the passenger seat will have a much greater effect your (driving) experience...

Fierofly

Sneaky Pete

alpine003

Eibach Pro-Kit along with either Koni FSD or Koni Yellow on their softest setting will usually yield a more compliant ride over stock.

Not really sure what effects the C4 springs will have except lower your ride and possibly shorten the life of your shocks. It may actually provide the same kind of ride or rougher since now the pistons on your shocks are compressed and operate at a lower point which has more aggressive valving and there's chances you will be riding on bumpstops over certain bumps.

If you're doing the labor yourself and got the springs for free, I don't really see any risk in trying except your time. Otherwise there might be better alternatives.

dporto

Koni doesn't make a set of springs for C4/C4S/Turbo... C4 spring should be the same or close to those on the C4S...

strathconaman

I am beginning to learn that there is a almost total lack of verifiable data on any of the stock or aftermarket systems. I am thinking now of going the PSS10 route.

To be perfectly honest the problem isn't coming from my chair. The near constant noise seems to be coming from the passenger side of the car...if you know what I mean.

alpine003

Correct. Koni makes shocks. Koni does sell kits that package springs that are made from other manufacturers.

5CHN3LL

Removing the passenger seat should take care of your suspension-related noise.

white out

C4/C4S and Turbo use the same suspension design.

dbarks

I have a 2003 C2 that had Bilstein HDs on it when I got it. I thought the front was OK but the rear too stiff/hard on rough pavement. I kept the stock springs and put on FSD's. The sharp impacts are better especially on the highway. Cracks in the pavement around the neighborhood don't seem that much different. I have a set of Boxster 17" wheels with Conti DWS tires that make the whole package pretty good. The PS2 tires on 18" wheels I use for the track are noticeably stiffer/harder.

A few data points for you, hope it helps.

strathconaman

Thanks. I don't have the option of 17s, my understanding is that they won't clear the caliper on a c4s.

The FSDs look like a good idea.

charlieaf92

In my initial research on the C4S I remember seeing a magazine article that said in the US, the C4S did not receive the lower suspension. It didn't go into many details and I can't find it for reference, but if its true then the comment above about it sharing the same suspension as the C4 would make sense. It may be identical.