Bullseye! You are correct about Koni Sports Car Challenge Aero and the rear diffuser isn't approved. The "spirit" of the series is to have "stock looking" cars that john q public can identify with. Look at the website and you'll see no cars have any medium or large wings. All of them are the small little guys like the MSpeed wing.

Read the rules and that will tell you everything. www.grand-am.com go into "competitor Information" at the bottom.

Do the homework. Google is your friend.

 

That's what I thought. It's funny because I'm surprised with rules like this that it's really popular and all. Me personally, I like the idea of making a monster and then putting it out there against other monsters. The limit simply being what the tuning shop/team can and cannot do or come up with. I mean having some rules of course, but things like not being able to change ignition, or go with japanese domestic bumpers from popular tuning firms isn't for me. Especially (correct me again if I'm wrong Eric) but the rule about not being able to at least change out clear corners? Thats just silly.

 

Excellent thread, and apologies for the slight thread drift, but:

I did post this question in the STX thread on the racing forum. Both Jason and Mark said I would be risking a protest if I did not locate the inlet of the actual cat within 6" of the inlet of the OEM cat, as opposed to locating the cat anywhere within the mid-pipe.

I do agree that the rule could be interpreted as you have above - I did the same thing, which is why I asked. It's frustrating because I'm about to cut up a RB midpipe and weld a cat & resonator in. Perhaps I should post on the SCCA forums.

 

Silly maybe, but Eric did mention:
Marketing in many ways is the driving force that funds motorsports. I can say the following about my personal RX-8 purchasing reason...

I previously owned a 2.5L Subaru WRX, and I was an avid fan of the Koni Challenge and the Grand-Am Rolex series for years (3+). Because of teams like SpeedSource, Meyer-Motorsports, Roar Racing, etc., I specifically wanted to purchase an RX-8 for my next car. These cars were successful on the track and I could buy one on the showroom floor.

 

Sorry, I didn't have time to read through the rules because I had to start working Thanks for the PM though!

 

Thanks for clarifying. So we'd only have 6" to play with then. Maybe we could make the header wind around the engine bay and collect next to the sway bar then swoop back to the cat.

 

It really is things like this that make these races so great. Was down at MidOhio a couple weeks back for the Grand-Am race and you would be surprised how many people just come look at the cars that we drive because they are out on the track. Last year Roar Racing even brought down one of their cars and parked it in our car corrale for a day. Car fit right in.

As for your question about clear corners, the Grand-Am cars don't have any side markers.



...the KONI cars do...



...and just for good measure and not to pimp out SpeedSource in Eric's thread...

 

George,

I have the same interpretation of the rule - new inlet must be within 6" of the OE cat inlet.

Here's a pic of the stock midpipe for reference:



The way I see it, we have roughly 7-8" to play with as there's roughly 2" before the actual cat begins.

My $0.02...

 

try again (both of you), reading comprehension FTW:

 

Let's analyze this and Mark please provide your interpretation as well.

I read this as there are two rules here one for single cat. OE configurations and one for multi cat. OE configurations being replaced by a single unit. The intent of the rule appears to be so they both net the same configuration.

STX, STU:
Any high flow catalytic converter(s) are allowed, but must attach
within six inches of the original unit.

This says to me you can put it in a different position and can move it so that there is 6" of play either way.

Multiple catalytic converters
may be replaced by a single unit. The inlet of the single
replacement converter may be located no further downstream
than 6" along the piping flow path from the original exit of the
final OE converter.

This says to me the inlet of the new cat. converter can be 6" further downstream than the EXIT of the furthest downstream cat.

So is this a double standard? Multi cat. cars can move the converter further downstream than single cat cars? If I interpret the first part of the rule I can move my cat. 6" further down. If I interpret the second part of the rule I can move the cat. the length of the OEM converter+6" or about 26-27".

Mark what is your interpretation of this rule?

 

that's exactly what it says, I don't see the issue, stop trying to torture the wording, it's not two rules, there's a general announcement and then they added further detail for clarification

this is not an STX thread, try to stay on topic for once, please

 

Thanks Mark. Looks like we're in business then Eric. From my measurements, this is where 18" back would roughly put us:



We would then need to locate a cat within 6" of the final exit.

 

assuming the header actually functions the same with a cat on the end of it, the cluelessness never ends ....

 

Dude, it's called setting requirements.

If Eric is offering to sell a header but it requires longer runs he should know what the autoX community would need so he can decide if he wants to support their rules or not. If he makes a header and mid-pipe system without a cat. or one with a cat. but it is too far down the pipe then no one in STX can use it. He loses business and you and the others lose an option for what could be an exhaust system that is finally worth the money.

I agree the cat. converter will have an impact on his current design. It would be up to Eric, again, to test this out and see if this is still effective. But if he doesn't know his design constraints he's just guessing.

How about actually adding your interpretation of the rule instead of heckling from the peanut gallery. Do you think we get 6" to play with or 24"?

 

^Honestly, I don't really think Eric is worried what the autoX community needs right now. The purpose of his thread was to show what he as a PRO race team owner has done to make his cars competitive, that's all. It was bad on my part to suggest he think about selling these custom headers...he really does not have the time to test, produce, and market this on a large scale. He's a pretty busy guy.

 

Yep.
Gain 8, lose 15.
So, you just lose a little less.
For some people losing less is the same thing as winning.

Which is why another pro will do this for him as a licensee.

 

You are right, he doesn't have the time to really mess with it, but I could see it happening. If he works with an existing company to make the headers available to the community for a cut. Another company does the manufacturing, he just provides the design they worked out. It is a win-win for everyone, since the community gets a race-proven header, the manufacturing company gets a proven product that they don't have to price insanely high to recoup the cost of development, and the team gets some more cash and probably more fans/followers.

Don't get me wrong, I am not saying "ERIC PLEASE DO THIS", because I am not. He has goals and concerns that have nothing to do with pleasing us, and frankly, he would be completely justified and right in not bothering with our circle debates. The fact that he comes on here at all is a benefit to us, and to further share this type of information is downright awesome of him.

The only statement I am making is following the same line of progression in history. Race teams spend the money (hopefully with sponsorship support) to develop improvements that then make their way down to the consumer as mods (either directly or via information that speeds up development), then eventually, the production line as standard.

If he does decide to open up further, or take this on, more power to him, it would be awesome. But chances are he won't because he has other concerns, and more power to him in those concerns.

Eric, I seriously wish you the best, we are rooting for you

 

I am by no means trying to put words in Eric's mouth. He was asking for information on the stock setup so I thought I would contribute additional information on autox restrictions on the stock set up in case he is looking at creating something.

Sorry to drag this thread down a rathole.

 

If you don't mind disclosing the information, roughly how long have you got your primary header lengths now, and would you go longer if you had more room?

 

I'm curious on where to locate the O2 sensors for this kinda setup. Should they be in the center pipe with gases from both rotors?

 

I think you want the wide band O2 sensor in the center pipe or at least where all outlets are mixed because you only have 1 sensor that feeds AF ratios to the PCM. You want an aggregate number. if you picked up from only one of the outlets you wouldn't get information about both rotors.

 

Correct. You want to capture BOTH rotor chamber's A/F data. We tried to do individual cylinder/rotor trims (using an O2 for each) but it was too costly in software programming).

Locate the sensor as far "upstream" as possible while still collecting data from both the front and rear of the motor.

 

Ok, cool. Ya I figured the center pipe was the best option since I'm going to take the piping out 6" or so past where the header currently ends then collect them in (similar to my header on the 12A in my 7). I plan on using 2" piping for the header (just like on my 7) but I'm torn as to collect it into 2.5" or 3" piping out the back. My 7, which is carbed with a 465cfm on the ol' 12A uses 2.5" piping but I feel that the 8 can flow more so I'm leaning toward 3" out the back. I plan on sticking to the style i used in my 7 with the header back, a single resonator in the mid-pipe then 2 mufflers after the axle.

Opinions?

I'll have pix of the whole thing soon as it's done, but that'll be a week or 2 since I need to get the back breaks hooked up and bled on the 7 so I have a car while the 8 is over at the exhaust shop.

 

2.5" is good to 230 - 250 engine hp

2.75" is probably ideal for the top NA Renesis engines, but isn't very practical so 3" is the usual default

MoTeC can handle the individual monitoring and trimming if it's within the rules/cost factor

 

Is this the Pro-Lite 9.8 lb wheel?