SPC LCA.. legal for stx?

[Skurj]

Can't search for SPC ..

But I did read somewhere that the SPC LCA's are not legal for STX.. but I don't recall why, anyone?

Was going to buy a set then I read that on here somewhere!!.. so now going with Whiteline.

[Lynxis]

Originally Posted by Skurj

Can't search for SPC ..

But I did read somewhere that the SPC LCA's are not legal for STX.. but I don't recall why, anyone?

Was going to buy a set then I read that on here somewhere!!.. so now going with Whiteline.

I guess they have a bit too much metal in the bushing to qualify as an OE replacement so they are illegal for STX. If you are just doing local/regional autocross, I doubt anyone will care, but if you are serious about it then spend the extra for a legal arm. Whitelines LCA differs from SPC only in that they use a type of rubber bushing so it's (supposedly) legal.

[mav1178]

SPC no, because the default bushing is ball bearing. STX requires OE-type bushings which mean they have to be metal sleeve within rubber or similar bushing.

[strat61caster]

^ that

Here's a video describing it:



[ame="https://www.youtube.com/watch?v=oBNUhrvA7wA"]SPC Performance xAxisâ„¢ Sealed Flex Joints - YouTube[/ame]



Edit: personal opinion, there's not much advantage to keeping it, it would just be a **** move to protest at a big event to knock you out of trophy's/contingency, I personally wouldn't take the chance but you can always pick them up and have the bushings pressed out and replaced down the road.

[cjd]

I forget who makes them but there are replacement bushings that are legal. Bumps the price up of course.

[JazzleSAURUS]

Originally Posted by cjd

I forget who makes them but there are replacement bushings that are legal. Bumps the price up of course.

DIF makes one.

http://www.frsport.com/DIF-10594-Str..._p_445911.html

[renfield90]

Originally Posted by strat61caster

Edit: personal opinion, there's not much advantage to keeping it, it would just be a **** move to protest at a big event to knock you out of trophy's/contingency, I personally wouldn't take the chance but you can always pick them up and have the bushings pressed out and replaced down the road.

There is quite a bit of advantage. A proper STX suspension is stiff enough that bushing compliance becomes a significant portion of the total movement in the system. Problem is solid metal or increased metal bushings will also make life untenable as a street car.

I'm pretty easy going about little stuff, but I don't consider this little and that's why I keep beating this drum. The rules are very explicitly written about how much metal should be in the bushing in order to prevent the class from turning into SP (textbook definition of rules creep - SP was intended for daily driven cars once upon a time).

[strat61caster]

Originally Posted by renfield90

There is quite a bit of advantage. A proper STX suspension is stiff enough that bushing compliance becomes a significant portion of the total movement in the system. Problem is solid metal or increased metal bushings will also make life untenable as a street car.

I suppose your right and I might change my tune if I held this in my hand that it offers and advantage in keeping the static alignment more consistent.

The OE bushing is pretty damn stiff, same as aftermarket. My gut was that the spherical would allow for freerer suspension movement and that was the advantage, which imo the OE and aftermarket rubber bushings swing up and down with zero resistance.

[Lynxis]

Originally Posted by strat61caster

I suppose your right and I might change my tune if I held this in my hand that it offers and advantage in keeping the static alignment more consistent.

The OE bushing is pretty damn stiff, same as aftermarket. My gut was that the spherical would allow for freerer suspension movement and that was the advantage, which imo the OE and aftermarket rubber bushings swing up and down with zero resistance.

In our cars, I have a hard time believing there would be any time differential between 2 cars using a LCA with a legal bushing vs an illegal bushing if that was the only thing different. The other end of the arm still has the same bushing from the strut after all so the difference would only be effectively half at best.

If you change other major bushings, then I can definitely see there being a difference and the rules have to be written to reflect that so they just say that generally speaking, you cannot change the type of bushing or the metal vs rubber content in the bushing. Unfortunately, it's not feasible to make an exclusion for something like this in a class with several different cars where each car would benefit more or less from certain bushing changes.

So I've always just taken it as an "it is what it is" type of thing.

[strat61caster]

Originally Posted by Lynxis

In our cars, I have a hard time believing there would be any time differential between 2 cars using a LCA with a legal bushing vs an illegal bushing if that was the only thing different. The other end of the arm still has the same bushing from the strut after all so the difference would only be effectively half at best.

I think it would make a difference having a more consistent rear end alignment would mean it's more predictable and allow a driver to get on the gas more reliably... but we're talking hundredths of a second quicker out of a corner.

Most of us aren't driving well enough for a few hundredths to make a difference which is why I wouldn't make a big deal about it, but I understand others being close enough where it matters.

Pulling up 2016 national results, 4th-8th is covered by less than 1/10th of a second on the combined results. @renfield90 was only 0.2s out of a trophy spot, over a nearly 2 minute (combined) course, being able to squeeze on the gas harder and earlier adds up quick.

[Lynxis]

Originally Posted by JazzleSAURUS

DIF makes one.

http://www.frsport.com/DIF-10594-Str..._p_445911.html

Nice that someone makes an affordable ST legal bushing replacement. I know I saw one a while ago that was asking $200, nearly the value of the arms by themselves and was putting the SPC arms right close in cost to other, better ST legal arms.

[JazzleSAURUS]

Originally Posted by Lynxis

Nice that someone makes an affordable ST legal bushing replacement. I know I saw one a while ago that was asking $200, nearly the value of the arms by themselves and was putting the SPC arms right close in cost to other, better ST legal arms.

You can also buy SPC arms with the DIF bushings already pressed in, I believe directly from DIF.

It's a good value if you're trying to stay STX legal.

I have a tenancy to show up to autox in cars that are awkwardly between classes, and just run as hard as I can for the smile on my face and not care about placement.

[redlined600]

Originally Posted by Lynxis

In our cars, I have a hard time believing there would be any time differential between 2 cars using a LCA with a legal bushing vs an illegal bushing if that was the only thing different. The other end of the arm still has the same bushing from the strut after all so the difference would only be effectively half at best.

If you change other major bushings, then I can definitely see there being a difference and the rules have to be written to reflect that so they just say that generally speaking, you cannot change the type of bushing or the metal vs rubber content in the bushing. Unfortunately, it's not feasible to make an exclusion for something like this in a class with several different cars where each car would benefit more or less from certain bushing changes.

So I've always just taken it as an "it is what it is" type of thing.

I think your last line says it all. We can all argue the validity of the rules endlessly but the bottom line is, that is the rule. One could always write a letter if they want it changed.