kauaian

iTrader: (18)

I actually got a response in 2016 from them (KW) when I had a damper rebuilt. They stated currently there are no options for a heavier spring rates and that it was not something they were going to do in the foreseeable future. Mind you this was not KW North America as I was living in Germany at the time.

I also contacted RSR about their i-sport coils and got the same answer.

RRRacing

iTrader: (1)

I think the reason you guys are getting this response from KW and RSR is that their shocks cannot reliably handle high spring rates, and they know it. KW's in particular are twin tube shocks which are not well suited for high spring rates.

As many have noted, higher spring rates are essential to make a relatively heavy car like the ISF handle really well. If you look at the suspension tuning that goes into making other heavy cars like Camaro ILE's or Mustang GT350's, an essential component is to increase spring rates significantly in order to control weight transfer, particularly with the extreme performance rubber those cars are running.

We go into some of the technical details here: http://blog.rr-racing.com/news/categ...ension-design/

Having said all that, here are some details on our new Afco Racing Shock based coilovers:

http://www.rr-racing.com/RR-Racing-R...isxfsu0001.htm

Our coilovers feature Afco Racing shocks, which (if required) can be rebuilt by us (same day) or any number of other Afco local dealers across the country. These shocks feature custom valving to our Penske valving specs, all billet alumium machined construction which saves 30+lbs compared to KW's, and are made in USA. Our coilovers feature Hypercoil springs, which are top level race springs also made in USA.

Please feel free to PM us for special pricing.

thanks!

Rafi