Contour Enthusiasts Group Archives Forums General Autocross and Open Track Pushing The Limits

...Of the rules.

This topic was broached about a month ago, but there has been something rattling around in my brain now for a bit. I forget the main thread of what my 'rule-bending' question was about. Maybe brakes...Anyway, I think Daveandrews brought up the subject of MSDS headers. The gist of the thought was that the GStock rules say that you can mod the exhaust from the cat back and from the cat forward. Then there is a sentence about not messing with the emissions stuff. Since the MSDS headers delete the pre-cats, does this mean this mod is breaking the rules? I have read and re-read this section a number of times. I think the 'spirit' of the rule is to forbid high flow cats. Does the fact that the CSVT has these silly pre-cats mean that we can't do the header mods that are within the realm of possibility for others?

I might have answered my own question here, but was wondering if anyone else had thoughts about it. It really seems to be a grey area, and anyone serious about doing this mod and remaining in GStock would be well advised to run this topic past a SCCA official.

Regards,
Mark

It is my understanding that the only thing that can be modified in the stock class on the exhaust side is the piping BACK from the cat (ie Cat-back exahusts) and that the exhaust has to exit near the stock location (ie no side exit pipes.) headers and such are not allowed in stock class. So the msds headers would be illegal regardless of what rule you go by (the mod or the emission)...
hope this helps

Matt

Unless they have changed the rules (entirely possible) I concur with El Pollo Diablo and don't think non-stock headers are legal in stock classes.

How about this, is the MSDS Y-pipe ok for STS (not G Stock)? It uses the stock cat converter unlike the SHO-shop Y-pipe, which I think is not allowed in STS. I believe the rule says something like CARB certifed headers are OK in STS, but since MSDS deletes the precats the headers themselves are not CARB certified. But no mention on the Y-pipe alone. I would think it would be ok, as most CARB certified V6 headers come with a Y-pipe.

No help from me Dan. There is a reason I stay in stock class and even there I can't be fully competitive because there are alignment and other tricks I don't and won't mess with out of ignorance, money, time, and commitment. STS seems like near open season by comparison, but I haven't looked at a rule book.

"17.10. ENGINE
Engine and transmission must remain unmodified, including emissions equipment, except as noted below:
Alternate air cleaner enclosures up to carburetor or throttlebody.
Headers, emissions-legal.
Engine management systems may be modified by the following means only. For the purpose of these rules the engine management system consists of two parts: the fuel control system and the ignition control system. Each system may be modified by either electronic or mechanical means but not both.

Electronic means to modify the engine management system are permitted by use of altered engine control computers and the installation of piggyback control devices such as VTEC Controllers and ignition controllers. Ignition amplifiers (MSD, etc.) that do not actively control timing are not considered "controllers" and are not permitted.

Mechanical means include the substitution of fuel pressure regulators, ignition timing manually adjusted beyond factory specifications or other similar adjustments.

All STS vehicles must comply with the Federal 49-state safety and tailpipe emissions test requirements as a minimum.

Short throw shift kits may be installed.
Any accessory pulleys and belts of the same type (e.g., V-belt, serpentine) as standard may be used. This allowance applies to accessory pulleys only (e.g., alternator, water pump, power steering pump, and crankshaft drive pulleys). It does not allow replacement, modification, or substitution of pulleys, cogs, gears, or belts which are part of cam, layshaft, or ignition drive or timing systems, etc. Supercharged cars are excluded from this allowance. This does not permit replacement of integral pulley-dampener/balancer assemblies. "

this is an unofficial transcript from the 2001 SCCA rule book regarding STS....

so in conclusion...if you go strictly by the rules:
-MSDS headers not legal (due to the removal of pre-cats)
-Y-pipe is legal the way i see it
with that said, i seriously doubt anyone would complain about the MSDS headers on a contour...even at a national level, since i doubt the contour would be competitive enough for anyone to start looking into things.....


my $0.02

Matt

Hmmmm. Well, I went and got my rulebook out of my car with the intent of posting the section in question; however, when I went to look it up, I found that Matt was right. No mods upstream of the cat are allowed (in GS). Oh well. I must have got that section confused with a similar one from another class.

I do agree with you, Matt, that no one would likely question you if you did make the mod. As was also mentioned in the previous thread, it will likely not gain you much anyway. If I weren't such a fuddy-duddy, I would drop a LSD in there (imho, the best mod for AutoX) and turn some heads.

Anyway, the gist of the thread is more long-term for me. The talk amongst the SCCA is that the Type R, GSX/Talon, and WRX all go bye-bye from G-Stock. I would like to have my car set up this year with all the tricks I can muster (time and cash allowing). This will allow me to get used to the car so that I will not have a 'learning curve' when next year comes around.

Thanks for the input thus far, and keep it comin' ; )

Regards,
Mark

The SHO-Shop y-pipe does squeak into STS, but barely, from how I read the rules. I also got several opinions on this before classing myself. Because the y-pipe is between the catalytic converter and the pre-cat, it is part of the catalytic converter system.

The STS rules only prohibit exhaust modifications in front of the catalytic converter, so as long as you're behind the precats, you're safe.

the STS rules do NOT prohibit exhaust modifications before the cat...after all thats exactly what aftermarket header/headers is/are....

Now the website has changed the wording again, and now they say that exhaust modification is only allowed "downstream of the catalytic converters", So as I'm downstream of the beginning of the system, it's grey area, and I was told that I'm OK for STS.

Before it said that it didn't allow anything in front of, like a pipe between the headers and the catalytic converter, as headers are a separate point.