Been searching but haven't been able to find much info on people who are or have used these springs.

I spoke with one of the guys at Z1Auto a few weeks ago, and he said these are probably the springs for me.

Basically don't want to upset the street manners, for the 4-6 times a year I may take the car to an Auto-X or HPDE. And also want a nice stance. I'd couple these with either Koni yellows or Bilstein sports.

 

If Z1 said it...it's probably true.

The only member I know of that had these is "chrisjersey06." PM him if you want.

 

The main thing that bugs is more drop up front than rear, which further necessitates the spring mount mod giving a pretty substantial total drop.

The other question that I posed in my last thread, and wasn't able to get an answer from Progress either, is why none of the spring manufacturers have taken into account the 2004.5+ revised spring rates.

So for instance, we take the Swift springs remove .5" from spring mount to even out the drop. We now have a car with 1.5" less suspension travel and essentially the same spring rate.

 

I had them on my 06 for two years. Worked great with my koni yellows for canyon runs. The progressive rates keep things civil around town, more so than the OEM springs. Drop wise, the rear is higher but not bad. I have no complaints for them. Mine are for sale if you are interested

Derek

 

Cobb did, find a set of their springs.

 

EDIT: Now I see why you said "find" a set of their springs.

Any idea if the 345/438 rates published are correct? Guess I'll need to call Cobb to find out. Although in the rear, that's like a 3% increase in spring rate.

When I called Progress to talk about their springs, didn't even know the change had happened. Guess I'm surprised that it was never questioned before.