[twiSTies]

Originally Posted by thrlskr

You missunderstood me. My laugh was in reference to the guy asking about what GC meant when Ground Control products were in his signature. Now I realize he wasn't asking he was stating a fact. Jokes on me. Anyway, I'm a big fan of GC, I visited their shop years ago and have used their products several times. I would have gone this route instead of the bilsteins had I been aware of it.

not liking the bilsteins?

[thrlskr]

Originally Posted by twiSTies

not liking the bilsteins?

I think the bilsteins are great; however, the GC/Koni combo offers more customization at an even lower price point.

[4banger]

It doesn't really matter. If the damping is way different than he thought it was, then he takes two seconds to throw some number in a spread sheet and have it spit out what new springs he needs to buy. Then he sells the old springs and is maybe out a few bucks.

Originally Posted by Splash

Which now begs the question...

Stretch, if you have GC housings and their front Konis, but used WRX housings and standard Koni inserts out back, don't you now have a mis-matched set of Konis?

I mean, the GC ones are custom-valved and the OTS inserts have stock Koni valving.

[stretch]

Originally Posted by Tim Flat4

Please excuse my ignorance Stretch but if one were to follow the "staged" path that you included in your first post wouldn't the said person be buying the GC housings twice (once for the stock strut and again when upgrading to Koni SA/DA strut inserts)?

The reason I ask is because I'm about to start modifying my STi's suspension, starting with TiC bushings and Cobb sways, then springs shortly there after. I'm coming from a 00 2.5RS and the GC/Koni combo is widely used with that chassis with great success. Now that I know I can use the same combo for my 05 I'm considering it but I don't know if I want to buy the housings, struts and camber plates at the same time.

Let's make sure the terms are staight- the "housings" refer to the strut housings that the Koni struts install into. You won't need any for the stock struts, just the Koni's (and only up front, if you use WRX donor struts in the rear).

Yes, you do have to replace the coilover sleeves since the Koni coilovers use a different design than the stock housing. I'm talking only about the threaded cylinder that the spring perch sits on. However, these only cost $15 each. I didn't realize this when I wrote the original post, sorry.

So, you really don't have to spend on any two big purchases at once. And, better yet, everything is reusable and interchangeable between the stock and Koni struts, save for those $15 sleeves.

Originally Posted by Splash

Which now begs the question...

Stretch, if you have GC housings and their front Konis, but used WRX housings and standard Koni inserts out back, don't you now have a mis-matched set of Konis?

I mean, the GC ones are custom-valved and the OTS inserts have stock Koni valving.

Both sets of shocks should be matched to the car. GC specs their shocks based on vehicle weight; Koni builds them to the specific application (in this case a regular WRX). Regardless, rebound is adjustable on both, so it's only the bump valving that I need worry about.

I believe shock tuning is done based on spring frequency. So, in that sense, it matters not what car the shocks go on, but what the spring frequency of that car is. You tune the shocks to a spring frequency. GC knows what spring rates I've chosen and the weight of the car, thus they know about how to valve the strut. Likewise, Koni did their own measurements for the WRX dampers and assumed a moderate spring rate hike. What's left up to the damper designer is how digressive to make the damping curve, which in turn will affect how the car transitions in and out of turns.

The rear WRX Koni's have quite a bit of bump resistance- this is generally good for performance but bad for ride quality. Should the GC Koni's have as much bump resistance, I'll be happy- the WRX Koni's already feel nice. Should they have less bump resistance, I'll be even happier- it'll likely promote rotation on corner entry. But honestly, I'd expect the two struts (GC and Koni off-the-shelf) to be valved very similarly. Maybe Mark can elaborate here?

Regardless, I'm not too worried about it. If I was, I'd of gotten the double-adjustables and tailored the bump valving too.

I should ask Mark for a shock dyno plot. I know they have a shock dyno in-house because I've read they ship Koni's preadjusted to their optimal damping level for some applications. I didn't ask for this knowing that I'd muck it up anyway- I like to tinker with things.

[Splash]

Right, but if Koni built some of their 1198s for Subarus (likely since nothing else uses the same shafts), Koni would also have likely valved them for the application. For GC to go and have those custom valved would seem redundant if the target valving rate was the same for both.

If the targets are different, then you have GC's target on the front and Koni's target on the rear. If the targets aren't different, there should have been no need for a custom valve.

Either that, or the custom valve isn't really all that custom... <grin>

[Tim Flat4]

Thanks for clearing that up Stretch. I thought the sleeves were what made up the majority of the cost of the GC set. If that's the case then this seems like an excellent way to go about stepping up.

[4banger]

I saw a BMW application that used 1198s on the GC website.

Originally Posted by Splash

Right, but if Koni built some of their 1198s for Subarus (likely since nothing else uses the same shafts), <GRIN>

[stretch]

These are definately unlike the WRX Koni's. I see no model number on either the unit nor the invoice, but they're much shorter and under gas pressure (they WRX units are pure hydrolic). It looks like these will provide between one and two inches of bump travel (depending on ride height) prior to hitting these new, softer bump stops with total bump travel being over double that of the stock struts. Total suspension travel (as I could compress them with my hands) is 5.5 inches. As you can see, I ordered 9" long 315lb/in springs.







I got the single adjustables, leaving me with holes in the bottom for where my second adjustment knob could have been.

I'm waiting on some Whiteline "Max-C" camber plates to arrive (bought 'em used, cheap) to arrive before the entire assembly goes on, and those arrive Tuesday. I already have Koni Yellow's in WRX housings with Ground Control coilover sleeves and 8" long, 250lb/in springs in the rear.

[ButtDyno]

Hey, those look familiar.

How long are your bumpstops on the front/rear? Looks like 2" in the front.

john

[BM_STi]

I'm licking at my chops to get my set of DA Koni/GC coilovers. The rear struts had to be special ordered.

[stretch]

Originally Posted by ButtDyno

Hey, those look familiar.

How long are your bumpstops on the front/rear? Looks like 2" in the front.

john

You got it, two inches. However, the very first progression is hollow on the inside and very soft.

[twiSTies]

how well do you think those tabs will hold up over time and is the total gain in strut travel over the stock struts enough to make a good difference?

[stretch]

Originally Posted by twiSTies

how well do you think those tabs will hold up over time

Just curious- why would I worry? Those mounts are pretty standard- heck, I'm impressed GC replicated the OE style. Japan doesn't always do that. Anyway, I've used zip ties in lieu of welded mounts in the past, I'm not too worried about that! (The zip ties held fine.)

and is the total gain in strut travel over the stock struts enough to make a good difference?

Um, yeah! On a 1" lowered STI on stock struts, you'll have roughly 0.75" of bump travel. With these, I estimate you'll have in the neighborhood of 3" of bump travel at the same ride height. That's four times as much bump travel.

Droop travel would be a problem at the stock ride height and/or on very soft springs, though. On firm springs and/or a lowered ride height, there's enough travel to let the spring completely unload- just barely, like you'd want.

[thrlskr]

Wow, that is a hell of an increase in travel. Now I wish I took the bilsteins apart to measure. What are your thoughts inverted vs. non-inverted?

[Splash]

Course of the two stretch, imagine the possible roll with 3" of bump travel, and 3" of droop travel...

Heh heh.....