I have PSS9s and would like to improve them for my driving style.....

Dave at DDM said (and I will call him) that the springs did not match the dampers well...... should I go up in spring rate and to what????

anyone have ideas and/or experience?

 

Just going to a linear rate 350lb/in spring in front is a nice improvement. It works very well with the standard damper rate and balances with the stock rear spring rate better than stock progressive rate springs, IMO.

By stock, I mean the springs that Bilstein ships with the PSS9s.

Scott
90SM

 

where would you get them from?

 

H&R 2.5"ID race springs are available from allsprings.com, amoung other places. Price was $87.98 plus tax and shipping for two springs. Very good service.

H&R website with distributor list: http://www.hrsprings.com/site/index.html

I'd suggest 6" long springs if you are using 350lbs/in. You'll probably need different camber plates, but once you are set up for 2.5" ID springs there are all kinds of rates available. Hypercoil and Eibach also make fine springs in different rates / lengths combinations. I tried the 7" long Hypercoil first, but it was too long for my desired setup and they didn't make a 6" spring so I switched to H&R.

There is no ride penalty. It actually improves. Talk to Way about that. He has driven my car with this setup on the street. He also did the install, with his usual fine work.

Scott
90SM

 

What does Dave recommend?

Note that you cannot easily swap your current PSS9 springs for lineair racesprings, since these may not fit. You will likely need to get new spring (locking) collars with a ID that matches the race springs, and you need either to come with a custom top mount, or get pillow top mounts/camberplates.

 

You do not need new locking collars to change to 2.5" race springs in front. You do need a new top hat, or new camber plates that incorporate that feature. I chose the new version H-Sport camber plates, but they are not the only option.

The rear Bilstein springs are already a linear rate, but are not 2.5"ID. The switch requires a little more work, but is also possible. I haven't done that change myself, as just changing out the front springs accomplished what I set out to do.

Scott
90SM

 

I'll talk with Way..... Dave wants to she a "shock dyno" before he suggests anything

 

Pls post the dyno plot so we can learn from it.

 

"I'll ge right on it" - Bahamabart

seriously.... I am not going to do a shock dyno

 

So, Scott, are the front ones 2.5"? And, since you say the rear ones aren't, do you know which ID are they? Sorry to up an old thread but I'd like to purchase PSS9 shocks and replace the springs with Swift ones.

 

Front springs are 2.5" ID up front, at least at the bottom. The springs Bilstein uses are barrel shaped like the OEM springs so they are much bigger ID up top, hence the need to change camber plates or top mounts when going to 2.5" springs up front.

In back, the Bilstein springs are a little bigger ID, as is the perch, so the 2.5" aren't a relative drop-in like the fronts are. It would be possible to swap to 2.5" springs in the back. Do some post searching, the I know the info is on NAM somewhere from a couple years ago when I was contemplating the same thing. I chose not to change the rears as they were already linear rate, unlike the fronts, and they worked just fine with the 350lbs/in fronts that I went to, at least with my setup and for my dual purpose use.

Scott
90SM

 

Very helpful Scott, thanks. It was the lower ID I was interested in for the front ones, so 2.5" it is, good to know As for the rear ones, I'll do some research and think about changing only the front ones, the only doubt I have about this solution is that I've heard Swift springs don't sag, contrary to many springs used on coilovers (including top brands like H&R, Eibach, etc.) so I wouldn't want having a pair of front springs which don't sag and the rear ones which instead do, even if maybe after a long time.

 

Just a data point; I've had my PSS9s since the fall of 2004, with the H&R springs installed up front about two and a half years ago. No noticable change in ride height. Even if they did sag a bit, you've got adjustable ride height!

Scott
90SM

 

Thanks for the input. As for the rear springs, I found a topic about it but no definite answer, the guess is that they are 70mm but no certain answer about it...at least for now