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The aftermarket for shocks for the new generation WRX is almost non-existent at the moment. Subaru stiffened up the stock springs significantly for 09 (same rate as the STI) but kept the previous struts/shock, so it's at about 50-55% of critical dampening, which is not great for handling. The two options I'm look at are:

Race Comp Engineering is putting together a low volume custom run with Bilstein for non adjustable front struts/rear shocks. They have been described as M3/GT3-esqe in that they are comfortable enough for the street but quite capable on the track. By track, I'm not sure if he is talking about HPD or autox because I'm sure there is a difference in terms of shock valving. He is getting the prototypes pretty soon (mid January) so I'll be able to see some dyno graphs soon. The pros to these are: Bilstein quality/longevity, cheap rebuilds/revalves, pure bolt on front struts (not inserts), set and forget, extra travel compared to stock so springs can be upgraded (if I leave stock class). Cons: non-adjustable, more expensive (though rebuilding costs in the future may offset initial cost).

The other option is getting the Koni sport front inserts for the 05-08 Legacy GT....standard proc....gut the oem strut body, install the insert, etc. For the rear it gets a bit more interesting. The rear shock for the LGT has some short comings. The tophat will have to be drilled out by 2mm (12->14mm)...ok no big deal. The circlip position for the spring perch will be about 15mm too low.....I have access to a machinists lathe so I can cut a new groove 15mm higher. The final mod is the lower eye bushing. It is incorrect in two ways. The bolt hole is too large and the width of the bushing is too small. Some people have pressed those bushings out and pressed the bushing from the OEM WRX shock in (it's rubber so even though it's a hair large in diameter, you can force it with a press). However, if I undertake this, I'm going to turn custom polyurethane bushings with a steel pin that goes through the PU bushing of the correct bolt hole diameter and width. So the pros to this route (custom modifications aside): adjustable, cheaper than the bilsteins, possible more aggressive valving than the bilsteins at max setting. The cons are: rebuilding is more expensive, rebuilding might be necessary more frequently from what I hear about Konis, loss of about 10mm of shock travel, will not have in tact OEM struts.

What thoughts do some of the suspension gurus have on this situation? Thanks

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2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Ahhhh the age old fight of good vs evil, Chevy vs Ford and Koni vs Bilstein. There are fanboi's on both sides and I will admit to personally liking Bilstein's. That's what is on my car but Bilstein does not import the 240sx shocks for some reason, so I had to cobble together some shocks from a 3000GT.

Short story: If this is a street/fun car, get the Bilsteins, IMHO.

Longer story: I have owned both Koni's and Bilstiens over the years and was happy with both brands. The Koni yellow strut insert hasn't lasted very long for me. It seems that the skinny shafts and the large side loads blow them. I know many others that have come to this conclusion. I like the adjustability of the Koni but I like the "feel" monotubes better.

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02 Focus SVT
STF 9

I'm a Koni fanboi, and proudly so. However, I've never owned a set on a mac strut car. That said, if I were you, I'd do the Bilsteins, mostly because they allow you to stay in stock class. Most of those little modifications you'd need to make the Konis fit would kick you out of DS.

It looks like AST makes stuff for a current Impreza, but you'll probably have to pay big dollars to get it. http://www.ast-suspension.com/comprace.asp?make=Subaru

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

I've confirmed that all the things needed to get those Konis to fit are stock legal. What are you thinking is not legal?

Is 10mm less shock travel going to be a detriment from an autox perspective?

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Not until you hit a BIG bump or lower the car

_________________
02 Focus SVT
STF 9

Could be I've misinterpreted something you've said, but:



I don't believe drilling holes in your top hats is stock class legal. Again, could be I'm misinterpreting something you've written.



I don't see how a custom, polyurethane bushing could possibly be stock class legal. Well, there's one way, I *think*. If the bushing is part of the shock, as opposed to being part of the control arm, than I suppose that would be fine. I've never owned a car built in such a way, but I've never owned a Subaru, either.



I don't understand how a shock that has the side effect of reducing available wheel travel could be stock class legal. That sounds, to me, like the shock bodies are longer than stock, or the bumpstops are larger, or something along those lines. Again, never owned a Subaru, so could be that I've misunderstood what you wrote.

BTW, I wouldn't want to give up any suspension travel. With a stock class car, since you're running super sticky tires on what amounts to soft, OEM spring rates, the more available wheel travel the better, as far as I'm concerned.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

Drilling top hat: 13.5.C:

To facilitate the installation of commonly available aftermarket
shock absorbers, struts, or strut inserts whose shaft size is larger
than the center hole of an upper shock mount assembly, that hole
may be enlarged by the minimum necessary to accommodate
the shock shaft size, provided the following restrictions are met:
(1) the enlarged hole must remain concentric with the original
configuration; (2) the enlargement of the hole does not require
modification of a bearing (as opposed to a washer, sleeve, or
plate); (3) neither the hole enlargement nor the location of the
shock shaft changes any alignment parameter. Provided these
constraints are met, this permits enlarging of the center hole in
an upper shock mount with an integrated rubber bushing, where
the bushing is integral to the mount and bonded to the plate and
the mount is provided by the OEM as an assembly. This includes
drilling out and/or removal of the metal sleeve.

For the 'eye' bushing: 13.5.B:

B. The mounting hardware shall be of the original type. The use of
any shock absorber bushing material, including metal, is permitted.
Pressed or bonded bushings may be removed from standard
parts to facilitate the use of alternate bushings which fit in
64
the original location without alterations to the part. This does
not permit the use of an offset shock bushing. A shock absorber
bushing may be implemented as a spherical bearing. The bushing
attaching the end of a strut to the body or frame on a strut
type suspension is a suspension bushing, not a shock bushing.

For the travel: 13.5.A.4:

4. The fully extended length must be within plus or minus one
inch of the dimension of the standard part.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Drilling top hat: Legal. 13.5.C

Bushing in shock: Legal. 13.5.B

Up to 1" difference in length: Legal. 13.5.A.4

Seriously, this is all rulebook stuff that's spelled out clearly.

EDITED: Shoot, I hate it when I get interrupted during a post only to get beaten to the punch because of it.


--Donnie

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My Blog

Wow, that was coincidence .

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Sorry to have bothered you, Donnie. You're right, the stuff is in the rulebook, and I stand corrected.

However. I'm having a hard time figuring out how 13.5.A.3 and 13.5.A.4 can coexist. I can't envision a 1" shorter (or longer) shock that still manages to have the spring perch "in the same location relative to the shock mounting points as on the standard shock."

I'm still a little unclear on how that's possible.

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Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

It's just the emphatic nature of your post and how it could mislead everyone else. *shrug*



It's about the *shock*, not the spring and perch. Just because the full extension is an inch less won't make the car handle any better or worse *except* for the case where the thing has to go to full droop.

The distance from the lower mounting point of the shock to the perch is what defines the ride height. That's got to be the same. The length we're talking about is the shock PISTON, and that just affects the max and min travel, not how the thing sits at rest. The 1" play allowance is historical because many OTS replacement shocks (think Monromatics or whatever here) were off by that much (probably because they were using the same shock for different cars since they were "close enough" for tolerances in the old days). There's been talk at times of shortening that allowance, but nobody has asked.

And yes, you could potentially gain some advantage by using that allowance. That's an exercise to the reader to figure out how and if it's worth your dollars. Think stock car that likes to lift a front wheel. If the rear shock ran out of compression an inch sooner....


--Donnie

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My Blog

Yes, 13.5.A.3 will be met by turning the extra circlip groove 16mm higher on the rear shock body to meet the ride height requirement.

_________________
2011/2012 Autox VP
2013/2014.5 President
2013 Top Gun

2015 Fit

22R-EC => 4G63 => D16Y7 + D16Y8 => EJ255 + K24Z2 => K20Z3 + K24Z2 => K24Z2 + M54 => L15B

Alright, that helps (I think), thank you.

I'd like to also verify that I'm reading something else correctly. 13.5.B. We can replace the rubber bushings that held the original shocks onto the car with spherical bearings? And it doesn't matter if the bushings are permanently attached to the shock or the control arm?

_________________
Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

No

A picture is worth a thousand words



You can replace THAT bushing. That's a rear shock on my 240. That metal sleeve is something I added, so just ignore that.

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02 Focus SVT
STF 9

What Ryan said. Only the bushing on the opposite end of the shock from the piston is in play here. And it must be ON the shock, not the control arm.


--Donnie

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My Blog