I finally got around to putting this stuff in to my 2003 WRX sedan. The springs are the STi RA, 217/195 rates. The Konis are the single adjustable (rebound) type.

Grip, tossability, precision, transitional response, brake dive, etc. are all greatly improved. I'm running 225/45/17 S-03s on 17X7.5 Enkei RPF-1s. The rear shocks are set at 1/2 turn from full soft, as are the fronts. I then set the fronts to 1/2 turn from full hard, and it really sharpened up the front end on my local tight mountain road. Clearly near full hard will be the choice for autocross, I need to try adjusting the rears in a few days.

Ride is actually improved at low speeds (under 25mph). Not as jiggily, more compliant.
At freeway speeds though, its a fair bit stiffer. Heaves or even just bumps in the pavement have the car doing a fairly pronounced and uncomfortable jounce. This is with the shocks set 1/2 turn from full soft. This is a disappointment. I drive this car a lot, and the roads in the Bay Area, CA suck. I may not be able to live with it.

Car sure handles better though.

-Mirror

 

that's going to be the springs i know, i've got the same springs on my WRX, and there is a fair ammount of reduction in ride comfort. you'll get used to it, i certainly did. the improved handling is well worth it in my opinion.

one other thing i found with me setup, is that the faster you go, the better it works. it that might not be the case with the Konis, but on the STi Spec -C struts, you notice bumps at 15 that you don't at 40.

 

Springs indeed! I almost cancelled my order with Rallispec after thinking maybe I was biting off more than I could chew with those rates. Stiff sidewall S-03s don't help in the ride department either.

I want to drive it with my winter set, 205/55/16s with 16X7 Raceline RL-7s. I need new tires for that combination, so I'll get some that ride well. I'm curious to see the difference.

The suspension certainly does work well when I'm ratting along at speed, but constant 75 on the freeway gets really tiring, really fast.

Guess I'm just getting old.

 

Reviewing.....

 

i'm running S03s as well, and the ride is pretty stiff. going with 16s and good tires, you'll have more sidewall flex, even on a stiff tire, so the ride shouldn't be quite as rough. even so, its not going to smooth out that much. my setup was pretty rough when i still had RE92s on.

 

UPDATE:

This whole spring/shock issue was really bugging me, so I took the car out for an extended drive two days ago along local freeways. I focused on dissecting each bump, and what the suspension was doing on compression, extension, then compression again. I just couldn't figure out why it felt so nasty.

I started to think of it logically. For the car to ride this crappy on what is only a medium aggressive setup, there has to be a mismatch between springs and shocks. Firming up the rebound on the shocks only makes things worse. Therefore, is it a mismatch between spring rates and compression valving?

I thought about that and took some bumps. Even smallish bumps were annoying. As I analyzed bump after bump, I began to realize that the shocks always seemed a click or two behind the springs. They didn't seem to do their part of the job damping the bumps. It felt like the springs went up, came back down and bounced, without the shocks damping that motion. I remembered what gtguy said in the thread (on nasioc), about him having no such ride problems with the same springs and STi struts.

I came to the conclusion: These springs have rates too stiff for the Koni compression valving settings.


Here's what happened next:

I woke up yesterday morning and beelined straight for Auto Innovations in Milpitas.

STi RA springs out.

Prodrive Springs in.



Problems solved.

NOW I have the setup I was looking for. Doing the good 'ol "press the springs against the garage floor with your hands" test, I confirmed that the Prodrives are indeed softer than the STi RAs, especially in the front. Prodrive doesn't give out rates, but I'll guess the front rates are in the low to mid 190s. Hard to tell with the rears, but they felt marginally softer than the RAs.

It took me all of 200 yards down the road to realise that this was the better combo. On the crucial freeway test, the small to medium bumps that had so irritated me before were now beautifully absorbed. No jounce, no gut compressing harshness. The Konis match the softer Prodrive rates so much better its hard to describe. Only a handful of the big bumps now give me a good oof. This is with the shocks set at full soft all around, the same as they had been on my prievious day and night's science experiment ride. I can't express how delighted (and relieved!) I am.

The penalties of this swap seem relatively small. The front is dropped a significant amount more, probably close to an inch. Its definitely as far down as I would want to go. Brake dive doesn't seem to be much increased, transitionals seem a touch less sharp. That's OK with me. I'll make up for that playing with the rebound settings and sway bars.

With the nose that much lower, the front roll center is lower too. A double edged sword here: this might be somewhat preferable for autocross, where loading the fronts on turn in and rotating the rear are mightily important. With high speed track stuff, it will probably be a disadvantage with the bigger difference in roll center points. The STi RA springs felt beautifully balanced in the medium to high speed stuff on the road. I will probably be giving some of that up with the Prodrives. Tomorrow I firm up the shocks and go canyon running again, so I'll report back with those impressions.

On a final note, the STi RA and Koni setup has been successful for other owners. For some reason, whatever that may be, it just didn't work on my particular car. Hmmm......

I like my car again. Joy.

-Mirror

 

Are you running the S-03s on the stock rims or did you score some different wheels?

The S-03s are definitely stiff sidewall tires. On the stock suspension, it firmed up quite a bit just with the wheel/tire change. Now its great, even better than stock in many instances.

 

i'm running 225/45s on 17x8.5 gramlights.

i'm not suprised that you elected to swap out the RA springs for something quite a bit softer. the RA springs are some of the stiffest arround, save for the STi tarmac spec springs. i don't think that there is an aftermkaret strut that is valved to damp springs that stiff, even on their 'hardest' setting (with the exception of things like the Tein HGs). the other solution would have been going with STi RA struts, which have the valving to deal with the aggressive spring rates.

i'm glad to hear that you were able to get the issue sorted out with a couple of test drives in the local hills.

 

Heh, those nice little roads are out there if you know where to go.

 

Just a quick question?

Would the SPT Susp. be the same ones? as far as the springs? I have the SPT kit on my 02 and at times it can be a little harsh. I was wondering if the Prodrive springs would fix the harsh ride that my car has.

Thanks Super.

 

From what I gather, the SPT springs have the same rates as the ones I took off. Take a look at the paint codes on the springs to be sure.

As far as replacing them with Prodrives, I couldn't tell you definitively how that would work out. It could theoretically create a mismatch in the other direction: spring rates too soft for the damping settings. Hard to say.......
-Mirror

 

Hey Mirror,

Thanks for the reply! Does anyone else have any input??

I wonder if the standard STI springs would be a better choice for my SPT struts than the Prodrive springs.

Thanks and Happy Holidays to everyone

Super:banana: