Spec Twin?

[blkwrxwag]

As I understand it, they want to make this class friendly to new people as well as seasoned competitors, whilst making the car good to drive on the street. While you may disagree, having "track pipes" is not considered to be DD friendly by most people, nor do they want people fabricating metal tubes in their garages or have the impression that to be competitive, you need one.

Are they having trouble putting that into words that make everyone happy, yes However, that's the intent as told to me by a SEB member.

[Twinz]

Originally Posted by strat61caster

"All exhaust gases must pass through two muffling devices, one in the mid pipe section, one in the muffler section, the muffler must be a minimum of 5" long."

That renders my Borla illegal, but it seems more understandable and enforceable.

Don't understand *why* they want two sound control devices, but at least they spelled it out.

*edit* just got a response to my request for clarification. *It's not official*, but the *intent* is as I originally thought. (We can't just run a pipe from the cat to the exit...we must have a muffler)

If the final rule turns out this way, the Borla and many other options will be legal.

[strat61caster]

Originally Posted by Shark_Bait88

I think the bolded portion is the part that would make the Works axleback illegal, since exhaust gases exiting the driver's side pipe/tip will not be routed through the muffler.

Well yeah, I wrote that because there's no reason why you can't bypass the mufflers in the current as written rules, other than being a good sport and understanding the spirit of the rules.

Originally Posted by Twinz

That renders my Borla illegal, but it seems more understandable and enforceable.

Don't understand *why* they want two sound control devices, but at least they spelled it out.

*edit* just got a response to my request for clarification. *It's not official*, but the *intent* is as I originally thought. (We can't just run a pipe from the cat to the exit...we must have a muffler)

If the final rule turns out this way, the Borla and many other options will be legal.

I had to look up what you mean and yes my idea would make yours not legal.
(For reference for anyone confused like I am)

No matter how they write it, several exhaust options for this car will not be legal. I agree with Max though, the rules need to be accessible to the everyman otherwise it defeats the point of the class and people would just stay in Street class even if they'r not competitive. If they went with a simple sound+weight rule you'd have a billion questions of "is this one legal? how about that one?" and what passes sound levels in February when you slap it on and test it locally may fail when you hit Nationals in September as the muffling material degrades or for some other wonky reason.

I like the direction they are headed, it makes a simple axleback a viable option, for <$500 you can get 80%-90% of the maximum benefit of the exhaust modification. That's pretty much all I want to put on my STX car to drop a few pounds and get clearance for a jack on a budget (but I'm waiting to see how loud it is with a header first, I don't want a noisy car). And it still leaves room for a more comprehensive catback setup for those that can afford it/want it.

[Twinz]

The sound question will be no more complicated than it has ever been in street class. And two resonators don't guarantee not blowing sound beyond the fact that these cars are quiet to begin with and straight pipes could probably pass with a turn-down in most venues...meaning any single resonator should make a twin safe from the db meter.

If they use the "a muffler" (or even "sound control device" or the like) language, then that should accomplish the sound goal and give people options.

The weight rule is a simple way to control costs, so I get that.

[DaWorstPlaya]

Originally Posted by blkwrxwag

Your combined midpipe/muffler must weigh => 18lbs.

There must be a resonator and a muffler - no straight pipes.

Pretty simple - don't overthink it.

Per the rules:

• The muffler and midpipe (as shown in the following figure) may be substituted provided the system
exits the car in one or both original locations.
o Weight – minimum, both muffler and midpipe (lbs.): 18
o Material for cosmetic exhaust tips is not restricted.
o “Track pipes” and “straight pipes” are not allowed.

I don't think the rules say you need a muffler and resonator.
And what does this mean?
“Track pipes” and “straight pipes” are not allowed.

To me that means muffler and/or resonator is legal. As long as you have one of these items it won't be considered a straight pipe. A lot of after market companies have non resonated catbacks but still have a muffler. My interpretation is those are legal.

[Twinz]

Originally Posted by DaWorstPlaya

Per the rules:



I don't think the rules say you need a muffler and resonator.
And what does this mean?
“Track pipes” and “straight pipes” are not allowed.

To me that means muffler and/or resonator is legal. As long as you have one of these items it won't be considered a straight pipe. A lot of after market companies have non resonated catbacks but still have a muffler. My interpretation is those are legal.

Actually the "provided the system...." language makes a single sound control device legit because it makes sure the system is not just a pipe from the cat to the exit.

I think any system with a working sound control device that meets weight is legit under the rule.

[Imp]

Originally Posted by Twinz

My Borla has a huge honking muffler...that runs from the cat to where the muffler used to be. It has a muffler. It's not a "straight pipe"....but the muffler isn't located in the stock location and, here is the important part....the pipe *after* the muffler is straight through.

Maybe I should just call them "really long tips"?

I also think it would be nice to understand the reasoning behind the rule beyond "because I said so."

Is it straight? Seriously, straight in these rules means... straight.


There are going to be some exhausts with longer straight sections than others. Going to be unavoidable. The new rules are trying to eliminate the whole "straight out the back" pipes (from exit of cat straight to back of car, or with a couple bends like I had on my RX8, hanging by coat wire).


What the new wording pretty well accomplishes is pretty close to: "Follow street rules, but must weigh 18 lbs and not be a straight pipe."


Even the OEM midpipe has a fairly "straight" section to it.


Try not to lawyer it when reading.


--kC

[blkwrxwag]

KC - does your sudden interest in this thread mean that you're finally coming out of "retirement" and joining SSC? I haven't seen you since about 2008 at Heartland Park.

[Imp]

2007 and yes.

Trying to find the sweet spot between models and mileage and years vs budget and weight.

--kC

[blkwrxwag]

Originally Posted by Imp

2007 and yes.


--kC

Marvelous

[Imp]

I was considering AS with a Z06. As close as you could get with spec in Solo... (co drove this year at Devens Tour) Finished mid pack after a) never driven the car before, b) haven't autoxed in years and c) it was on the wrong tires.

But when they announced SSC, it seemed much more logical. I hope to make nationals next year. We shall see. Depends on my work schedule and if I can swap some weeks with the other trainer. (Because I'm scheduled 10-14Sep already).

--kC

[blkwrxwag]

For those that don't know, when I first started in 2002, KC was like Subaru Autocross Jesus. Since then, well, let's not go there, but he used to be famous!

[Imp]

Yeah, I was brainwashed by Mazda when the RevItUp's came to town and got me in an RX8.


--kC

[Locust]

Originally Posted by Shark_Bait88

Considering the stock midpipe weighs 12.4lbs, I'm guessing that it's a combined weight of 18lbs not 18lbs/ea for a combined of 36lbs.

Otherwise everyone would have to go out and find a midpipe that's 6lbs heavier.

I also noticed that the material restriction was removed. Although it was still noted that exhaust tip material is unrestricted, which is weird.

Hmmmm. I could feasibly find a slightly heavier midpipe and use the exhaust I have then... Although I don't think such a thing exists.