I'm considering moving to stiffer springs for my KW V3 shocks. They normally use 5.5 inch (140mm) long springs. I have over 1.5 inches of thread available on the shock perch adjusters. It seems to me longer springs would give more movement before spring binding so I'm considering 6 inch springs. Is there a downside to moving to a longer spring?

 

6 inch should be fine. I ran in to problems with 7 and 8 in springs in both the front and rear. With such a long spring in the front, the spring perches were getting close to the upper a-arm and almost touching at low ride heights. In the rear, the sway bar pickup can interfere with the spring perch with long springs. Just measure or eyeball it to make sure you'll be clear of those areas.

 

Are these 2.5" or 2.25" springs? I ran 2.25" width 6" length springs really low without issues. This is on a different shock body, but the springs came from someone with KWs

-Marc

 

I was planning to use 2.5 x 6 inch springs on the KWs, either Swift or Hyperco. Will 2.25 inch springs fit KWs?

 

I have 800lb/in Hyperco springs for sale in the diameter and length you are looking for. I think they should work better on the KWs than the SRCs.

 

Right now I'm running 628lb/in front and 571 rear. My plan is to move the 628s to the rear and install 700 in the front.

 

If they're anything like the V3s I had on my Subaru, they use 60mm springs (ignoring the special progressive springs some models used). I was told by the vendor that 2.25" springs won't fit, but it looked like it could (never tried).

 

@robrob, there is a really good section in tune to win on how to choose springs. Depending on your level of competition and car set up, Carrol Smiths method might be a bit overkill. I would guess the shock travel would be limited before binding is an issue with a 6" spring. The KW springs are 5.5".

The KW springs are 61mm. I believe 60mm or 2.5" will both work.

 

I was running 7" 2.25ID springs but I lowered the car further and started getting some rubbing on the upper A-arm. Switched to 6" springs and it's perfect. This is with TTX dampers.

 

Thanks guys. I'm planning to at the very least get the V3s rebuilt over the winter and if possible get them re-valved and move up to slightly stiffer springs. When I was talking to the KW USA tech I asked about the Club Sport valving and he did say it was slightly different and used a different oil. If I can't get the shocks re-valved I may have the rebuilder put a slightly thicker oil in them--the Club Sport oil if possible.