Hey all, got back from my 2nd autoX, & had a few WRX specific questions, was wondering if y'all could help me out.

#1 Are pinks legal for Dstock? My understanding is any factory option is legal, & the pink shocks/struts/bars would give us a huge advantage over the standard factory ones. Not that I have the cash for that now, mind you, but I don't see much point in buying a front anti-sway bar for my current setup if I can replace the whole suspension package next year & still run in DS.

#2 What tires are you running on? I'm still on my RE92s, but it's clear to me that they won't cut it, so I'm looking around for something stickier. Here in Atlanta, Kuhmos seem to be the favorite on the WRX, & was wondering if that was the trend everywhere.

-Laters!
-Chris!

 

#1 - DS rules say you can use any shocks and you can change the front swaybar, but you can't touch the rear bar at all. And that's it. If those struts are at all different from stock, then they'd be out to. As for buying a new front sway bar now, I don't think there's a lot that'll do for you in DS. The car pushes as it is and a bigger front bar (by itself) will only make that worse. Put your efforts into getting as much camber in the front as you can (no camber bolts/ crash bolts allowed on WRX's).

#2 - If you have a second set of wheels, then Kumho's would give you a nice boost. That's pretty much the ticket for DS. If you only have 1 set of wheels or don't want to buy new R rated rubber, then Falken Azenis Sports are a good compromise tire. Pretty sticky, longer wearing, but a step down from Kumhos.

Meanwhile, work on your driving (which is MY issue) and you'll see the times come down no matter what setup you have.

Have fun!

Bill

 

I think the pink shocks might be ok. As for tires the auto-X specific Hoosiers are the tire to have around here.

The shock rule......


13.5 Shock Absorbers
The make of shock absorber may be substituted providing that the number, type, (e.g., tube, lever, etc.) system of attachment and attachment points are not altered, except as noted below. The interchange of gas and hydraulic shock absorbers is permitted. The following restrictions apply:
No more than two separate external shock damping adjustment controls. Gas pressure adjustment is not considered a damping adjustment.
Suspension geometry and alignment capability, not including ride height, may not be altered by the substitution of alternate shock absorbers.
Adjustable spring perches are allowed, but the spring load-bearing surface must be in the same location relative to the shock mounting points as on the standard part. Shims may be used to achieve compliance.
The fully extended length must be within plus or minus one inch of the dimension of the standard part.
Electronically controlled shocks may not be used on vehicles not originally equipped with such units. Vehicles originally equipped with electronically controlled shocks may use the standard parts or non-electronically controlled alternative shocks subject to all requirements of 13.5. Non standard electronically controlled active shocks are not allowed.
The mounting hardware shall be of the original type. The use of any shock absorber bushing material, including metal, is permitted. This does not permit the use of an offset shock absorber bushing. The bushing attaching the end of the strut to the body or frame on a strut type suspension is a suspension bushing, not a shock absorber bushing. Suspension bushings, including but not limited to those which carry the weight of the car and determine ride height, may not be replaced with bushings of a different material or dimension.
To facilitate the installation of commonly available aftermarket shock absorbers, struts, or strut inserts whose shaft is larger than the center hole of an upper mount assembly, that hole may be enlarged by the minimum amount necessary to accommodate the shock shaft size, provided the following restrictions are met:
the enlarged hole must remain concentric with that of the original configuration;
the enlargement of the hole does not require modification of a bearing (as opposed to a washer, plate, or sleeve);
neither the hole enlargement nor the location of the shock shaft changes any alignment parameter.
A suspension bump stop is considered to be performing the function of a spring. Therefore, the compressed length of the shock at the initial point of contact with the bump stop may not be increased from the standard part, although the bump stop may be shortened for the purpose of installing non-standard shocks. Bump Stops installed externally and concentric with the shaft of a shock may be drilled out to fit a larger diameter shock shaft. Bump Stops may be substituted for the purpose of installing non-standard shock absorbers.

 

Two issues against the STi parts make them illegal for DS:

1) they are not factory option, but dealer installed. In some instances port installed. As such they are not factory options and dis-allowed.

2) You can replace struts, but only the "cartridge". I know, I know, Subies don't have strut cartridges, but are a single self contained unit. Yup, that is why there is a Koni strut cartridge available (only one that I know of). You CUT open your existing strut assembly, remove all the internals, and then bolt the Koni in position. That is the only legal mod allowed (parts-wise) to the suspension. Even poly bushing are illegal, as well as strut braces.

The tires have been covered by the previous replies pretty well.

BTW: If just for autocross, and bragging rights, a setup DS car will beat an STX WRX (all things being equal, driver skill, etc). Reason, cause DS can use actual racing rubber.

 

I'll have to disagree with Subayai about the STi struts being illegal. As long as the mounting points, ride height, and alignment calibrations are unaltered from stock, you can use them. I haven't competed nationally in D-stock so I'm not an expert, but I know of a nationally competitive B-stock S2000 driver that has Bilstein coil-overs with a modified spring perch to allow for use with the stock Honda springs. His setup is perfectly legal.

AnimalMother

 

sti struts are perfectly legal in DS. you just have to use the stock wrx springs.

but why pay more for sti units when you can get konis that are adjustable for cheaper? that seems like the more popular route for DS wrx's

 

Yes the struts are propably legal, but all other components are not. For the struts to be legal they have to use the same mounting points and cannot allow for more camber to be adjusted than the stock struts. If the STi's are set so that you can adjust between say +.5 to -2.5 degrees of camber then they would be illegal. But I am not sure of there dimensions. This is key. I haven't measured nor seen specifications on, say the KYB AGX's, but all non-stock struts must have the same mounting specifications/dimensions as the stock units. In regards to spring perches, they are specifically legal, and are necessary to make sure the "stock" springs are in the stock location, and compression on any aftermarket strut. I look at the Koni's as the safest, and best quality aftermarket unit. No one, and I mean no one can argue that the strut does not meet the rules, since you are re-using it.

On the non-strut pieces the rules specifically state that they have to be the manufacturers stock units, and aftermarket pieces are not allowed. The STi is not stock, and would be considered an update, or backdate, which is not allowed in stock class. Even in regards to the bushing material (which really sucks).

 

As a DS WRXer with a fairly setup car... I'm going to agree with KC that an STX-prepped WRX is faster than a DS car. Kiko Seibt was markedly quicker in STX trim than in DS trim on the same test-and-tune course.

 

Ahh, ..... But what could a STX prepped WRX do on R-Compounds that would be interesting to see.

Has anyone here ever run the same course back to back in the same car on say Azenis and then Hoosiers.

Just wondering if the SM Pax penalty would be over-comeable?

 

I guess what my point was is this:

WRX D Stock PAX: .795
WRX STX PAX: .798

Now let's say you are racing on a course that takes a 1.0 PAX car (actually more like a kart) 60 seconds to complete (for a kart that is a big course).

The ideal WRX D Stock time would be: 75.471 seconds
The ideal WRX STX time would be: 75.187

3 tenths of a second. Now let's look at the cost:
D Stock
Struts $550
Stock Rims w/R rubber $800 (assuming Kumho)

STX
Coilover adjustable struts: $1500
Camber Plates $200 (+$200 for rear)
17/18 rims w?Falken Azenis $1200
Strut Braces $400
STi Engine/Trans Mounts $180
Stoptech front brakes $1500
Uppipe $150
CAI? $150

The cost difference for 3 tenths of second approx. $4380

I know that I would be smiling from ear to ear beating an STX prepared WRX in raw time, but since they are a fellow Suby owner I would show some restraint