Serious autocrossers rejoice! (I think.)

[BigBrother]

Serious autocrossers who haven't discovered this yet (and SHAME ON YOU if you have and it's not posted all over hell and back), please discuss. This is HUGE, and I am teh stokedz. I posted in the product review thread, and I'm putting it here now:

I just read, re-read, and read again the ST class rules in the '08 book. I want the FE5 control arms, but was pretty sure there's no way I could get them legally (I'm a stickler for rules; if I win in a grey area or that fact that nobody would know it was illegal, I'd still feel like I didn't win 'cuz I cheated).

WRONG. THEY ARE LEGAL IN STX (I think). Here's how/why:

The ST class definition states that all stock category mods are legal, plus "the additional allowances outlined in sections 14.1 through 14.10. We all know (or you should by now) we can get obscene negative camber in the stock rules with the stock struts. Moving on:

Section 14.8, subsection I, paragraph 2 states "On arm-and-strut (MacPherson/Chapman) suspensions, the lower arms may be modified/replaced OR other methods of camber adjustment as allowed by paragraphs 14.8.B, C, or G may be used, but not both." The subsections referenced talk about bushings and allowances for camber plates, and cam bolts.

SO:

As long as we don't install camber plates or other methods for altering camber beyond the stock setup already allowed by class definition, we can change our lower control arms!!!

Well, what's the big deal with camber plates or bolts (the use of which would eliminate the ability to use these control arms)? Getting more begative camber. Well - that's not an issue with our cars. With lowering springs and struts or coilovers without camber plates (how do pillowball mounts fit into this definition?), I can still get over 3 degrees negative camber within the allowed stock rule set! So I can lower my car with springs and struts, get -3 degrees camber, AND shave 30 or so lbs of unsprung weight with a stronger, stiffer control arm. LEGALLY!!

Possible Kryptonite: The section dealing with what's allowed in bushings is pairly detailed. I know the FE5 arms use different busshings - but i don't know what's different about them. If they are different enough that they break that rules section, and there's not a definition-legal replacement that works with both control arms, this won't be techincally legal.

Have at it boys, shoot me down. Otherwise - I'm buying these, and soon.

[FunkyStickman]

It sounds like a waterproof plan to me... BTW, all suspensions bushings are replaceable under stock rules, as long as they're not solid metal. I'm assuming you've got all the other goodies, like a rear strut bar, etc.? I just put one on, and it made a HUGE difference in stiffening up the back end.

[Eagle_f90]

I run in SM so the hole FE5 suspention is legal for me which but it is cool to hear that you guys in STX can run it.

[alredline04]

Stock for stock the the FE5's and our FE3's share the same geometry aside from a slight difference in caster. The bushings may be stiffer. I guess I am not on the same page here. I have the FE5's on springs and the car falls within the stock alignment specs every time. unless you are talking about a set of custom bushings or ball joint. It just seems simpler to slot the struts to get the camber you want and that falls within stock rules.

[Eagle_f90]

The FE5 control arms are stornger with a better bushing. You can also get poly busing for them to help with wheel hop. Because of the better bushings in the FE5 you can't use them in stock.

[BigBrother]

The bushing difference is almost forgiveable in stock. You can't use them in stock because they're a COMPLTETLY different control arm; the geometry is the same, but the actual construction is radically different. They're almost half the weight, and they're stiffer (the FE3's flex a LOT - a major contributor to our wheel hop) and significantly stronger. Camber isn't the objective here. The rules state that this is a camber mod, but we're taking advantage of that allowance to get something more - camber isn't an issue for us. We're getting less suspension flex and shaving a ton of unsprung weight.

You can change bushings - excepting solid metal - but they must be the same type. There's where I'm unsure - ther only weakness here. Is the superior bushing in the FE5 of the same type, just different construction? Or is it a completely different kind of connection? As long as all the connection points - bushings and ball joints - are of the same type between the '3 and the '5, we're good. I am so stoked to see what loding 30 lbs off the front of the car - in the form of unsprung weight! - feels like!

I don't care for the ewhole FE5 suspension - although I thought about it - 'cuz I'm going to run completely different springs and shocks anyway, lol.

The better wheel hubs from GMPP however, are illegal in stock or ST. Oh well - not ALL great news, lol.

[Eagle_f90]

Originally Posted by BigBrother

The bushing difference is almost forgiveable in stock. You can't use them in stock because they're a COMPLTETLY different control arm; the geometry is the same, but the actual construction is radically different. They're almost half the weight, and they're stiffer (the FE3's flex a LOT - a major contributor to our wheel hop) and significantly stronger. Camber isn't the objective here. The rules state that this is a camber mod, but we're taking advantage of that allowance to get something more - camber isn't an issue for us. We're getting less suspension flex and shaving a ton of unsprung weight.

You can change bushings - excepting solid metal - but they must be the same type. There's where I'm unsure - ther only weakness here. Is the superior bushing in the FE5 of the same type, just different construction? Or is it a completely different kind of connection? As long as all the connection points - bushings and ball joints - are of the same type between the '3 and the '5, we're good. I am so stoked to see what loding 30 lbs off the front of the car - in the form of unsprung weight! - feels like!

I don't care for the ewhole FE5 suspension - although I thought about it - 'cuz I'm going to run completely different springs and shocks anyway, lol.

The better wheel hubs from GMPP however, are illegal in stock or ST. Oh well - not ALL great news, lol.

If you jump to STX (stock might allow it to) you can upgrade to the FE5 front sway bar which is like 2" thiker then stock.

[kombi731]

thats cool
how much are they gonna cost you?

[Periodic]

Originally Posted by Eagle_f90

If you jump to STX (stock might allow it to) you can upgrade to the FE5 front sway bar which is like 2" thiker then stock.

TWO INCHES THICKER!!..holy moly i need to find me one of those! haha, do you have actualy measurements? our stock front is +/- 22mm (a little less than one inch....so I doubt the FE5 is around 75mm..hehe)

[Eagle_f90]

Yea yea I always scew that up, our stock is 22mm the fe5 is 24mm