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Best Road Race Exh. Long or Short?

Old 10-03-02, 12:42 PM
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Question Best Road Race Exh. Long or Short?

I see many IT cars running long primary (i.e. RB style) exhaust systems. But Paul Yaw's header is a short primary. and so is SDJ's design? Other than weight, why would you run a shorty stlye on an engine that lives a high RPM's?
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Old 10-03-02, 09:14 PM
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latest rotary racers have gone to the very short header and some different collectors. with restricted porting in some classes engine builders and tuners have focused on the exhaust for increased power. the RB header is a good off the shelf part, but some new thinking has produced some amazing results.
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Old 10-04-02, 12:08 AM
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Sounds great Tim, where can we find out more about the "amazing results"?
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Old 10-04-02, 06:56 AM
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Tim, I think I know what your talking about, but thats more on the port exit velocity which isint affected by primary runner length. On a stock port race motor a shorty header will be too short at high RPM's. I can't seem to grasp the theory that has people making these shorty headers for road racing.

Kill, look at paul yaws site on his new headers.
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Old 10-04-02, 08:18 AM
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I don't have any accurate numbers but if you want them you will have to buy or look like you are going to buy one of these exhausts. try AWR and Yaw for info on these headers. AWR has used these on stock port IT type motors. they work better at low and high rpm's
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Old 10-06-02, 10:01 AM
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We run Stan's (SDJ) Motor, exhaust and carb on our IT7 car. His header looks similar to Paul Yaws design.
I don't know the technical reason that it works but our car makes 124hp at the wheel on a basically stock motor with limited carb work and exhaust. BTW, thats up from 88rwhp stock.

The exhaust consist of the collected header to nascar style 3" oval tube and exits through a 3" in/out dynomax muffler.

If your wondering how this set up doe's. We finished 3rd over all in our region. Thats with 1 DNF. Also, The guy who finished first for the season is running the same exhaust/engine/intake that we are.

Mike
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Old 10-06-02, 05:23 PM
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Hey Mike!!!! Still havent put that RB system in the streetcar yet, but is sure looks nice on the garage floor! Does Stan's 3" pipe run under or over the axle?
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Old 10-06-02, 07:09 PM
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Originally posted by Rx7carl
Hey Mike!!!! Still havent put that RB system in the streetcar yet, but is sure looks nice on the garage floor! Does Stan's 3" pipe run under or over the axle?
Hey Carl.
You need to get that thing on your car! I almost wish I hadn't sold it. I just picked up another 1st gen for a street car. That exhaust would be sweet on it.
Actually, I probably wouldn't use it if I still had it. I have a very nice T2 motor and tranny sitting in my garage with no home. I've pretty much made up my mind that the new toy is getting the Turbo motor. All I need is an ECU and My good budy is a Haltech dealer .

Anyway, We run our exhaust under the axle. We chain the axle up so that it doesn't lay on the exhaust when the car is jacked up.

Mike
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Old 10-06-02, 09:41 PM
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Ok, stinkfist, you now have my attention.

How much did the SDJ header run? They have no price lists on their website.

I hate to use price as a determinant for what I buy, but when you're scraping the bottom of the barrel it counts.
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Old 10-07-02, 11:12 AM
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Originally posted by peejay
Ok, stinkfist, you now have my attention.

How much did the SDJ header run? They have no price lists on their website.

I hate to use price as a determinant for what I buy, but when you're scraping the bottom of the barrel it counts.
I can't remember off the top of my head but I think it was in the $350-$400 range. It's not cheap but they are hand made and are very high quality.

I would like To try Paul Yaws header on my race car, but I can't get in touch with him to even see if they are available.

I will check on the exact price when I get home.

Mike
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Old 10-07-02, 01:49 PM
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Originally posted by stinkfist


I can't remember off the top of my head but I think it was in the $350-$400 range. It's not cheap but they are hand made and are very high quality.

I would like To try Paul Yaws header on my race car, but I can't get in touch with him to even see if they are available.

I will check on the exact price when I get home.

Mike
Actually they are $530 as per the email I got back from SDJ.
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Old 10-07-02, 09:20 PM
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Originally posted by FPrep2ndGenRX7


Actually they are $530 as per the email I got back from SDJ.
WOW! Thats high. Ours was $450 but I think he gave us a break because we bought an engine carb and exhaust from him.

That really makes me want to get Pauls header now. I'm not going to drop that kinda cash on an exhaust for my race car. Hell, right now I have a RB dual header with custom dual primaries into a dynomax. It's not great but it was practically free.

Mike
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Old 10-08-02, 07:47 PM
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Yea but are Pauls headers ready for sale yet?
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Old 10-08-02, 09:39 PM
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Probably not....
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