Best Road Race Exh. Long or Short?
#1
Airflow is my life
Thread Starter
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?
#2
Rotary Enthusiast
Join Date: Apr 2001
Location: North Hollywood, Ca USA
Posts: 1,289
Likes: 0
Received 0 Likes
on
0 Posts
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.
#4
Airflow is my life
Thread Starter
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.
Kill, look at paul yaws site on his new headers.
#5
Rotary Enthusiast
Join Date: Apr 2001
Location: North Hollywood, Ca USA
Posts: 1,289
Likes: 0
Received 0 Likes
on
0 Posts
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
#6
Learn to swim.
Join Date: Jul 2001
Location: Mobile,AL
Posts: 1,301
Likes: 0
Received 0 Likes
on
0 Posts
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
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
#7
Airflow is my life
Thread Starter
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?
Trending Topics
#8
Learn to swim.
Join Date: Jul 2001
Location: Mobile,AL
Posts: 1,301
Likes: 0
Received 0 Likes
on
0 Posts
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 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?
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
#9
Old [Sch|F]ool
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.
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.
#10
Learn to swim.
Join Date: Jul 2001
Location: Mobile,AL
Posts: 1,301
Likes: 0
Received 0 Likes
on
0 Posts
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.
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 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
#11
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
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
#12
Learn to swim.
Join Date: Jul 2001
Location: Mobile,AL
Posts: 1,301
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by FPrep2ndGenRX7
Actually they are $530 as per the email I got back from SDJ.
Actually they are $530 as per the email I got back from SDJ.
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
Thread
Thread Starter
Forum
Replies
Last Post
4sfeedit
Canadian Forum
1
09-07-15 10:55 AM
4sfeedit
3rd Generation Specific (1993-2002)
10
08-16-15 01:42 PM
4sfeedit
Race Car Tech
0
08-11-15 04:11 PM