I have a rb header now what would be the best to follow this?
size of piping?
muffler inlet outlet size where to place them how many and so on
under or over the rear axel
where to merge the pipes header or farther back or dont merge at all?


btw this would be an a large street ported 12a with ported exhuast ports

 

2.5" all the way back. run a dynamax bullet as a resonator off the header and your choice of muffler in the back (magnaflow is what i like) and you WILL NOT HAVE THE BUMBLEBEE SOUND... just a very awesome tone and it wont be that loud. and not restrictive WOOT!


oh and go under the axle less bends the better

 

Which RB header do you have?

 

I think he has the road race uncollected header...

Here's a VERY rough outline of my plan:

 

I like your artwork.

 

Yeah... Me to, lol...

Did it on the paint program on my Palm handheld while tying to explain it to a buddy of mine, lol...

 

Do you think that setup is better than a collected header running to a single pipe all the way back? If so, what makes it better?

Matt

 

Put a single 76mm from header to tip,works WELL

 

anyone one else?? so far i like fb 11 idea the best

 

yea hes a genious listen to him

he likes cheese

 

i'm running pacesetter header to 2.25" piping to a 3A racing resonator (i think thats what it is) to a magnaflow 2.25" straight through muffler. and goddamn its far too loud.

still considering putting another magnaflow right after the header, then to resonator then to the magnaflow i already have.

....... damn these cars are loud.

 

I have the RB dis-assembled header kit to start off with. It leaves me with two 2" primaries that run down to where the stock main cat is, from which I will merge into a Burns Stainless collector/megafone. I'll also have a reverse cone at the end of the megafone to bring the pipe diameter back down to 2.5". I'll put in a V-band flange here. From there, I'll have a Magnaflow 18" long straight-through 2.5" in/out muffler as a presilencer. Then to finish it off, I'll run another 18" long Magnaflow 2.5" in/out.

I'm obviously bored outta my mind on a Friday night.

 

i put a custom straight pipe off of the factory exhaust manifold 2 inch diameter and goes to my factory muffler (probably leaks). it is pretty loud, but definantly not unbearable (double negative?) and it sounds cool to me. alot more power too especially at like 5k-8k rpms is alot faster.

 

Longer primaries will give you a bit more top end... the trick is getting the length right for port tuning...

I've still gotta calculate the length... I'm going to need get the stock length for and SDJ collected header primaries, and then multiply that by 3, subtract the length of the SDJ uncollected I'm going to get, and that'll be the length from my header to the collector... Should be somwhere near the rear axle I figure. I'm going to merge the pipes much like a SDJ collected header, then do a convential split back to my mufflers...

BTW, I'll probably be using these instead of, or with the pre-silencers...

 

running two pipes to the rear axle and then collecting and then seperating again can yield slightly better top end results... but at a sacrifice of alot more weight. not to mention it complicates the build process. as you stated you are doing math for a few slight extra ponies. it does work, but is it worth it? say you gain 5hp but also gain 20lbs. then it's null. also at an even higher sacrifice of low end grunt. if you had a bridgeport then this could be totally different. but to keep things simple and cheaper i wouldn't go that route. just run a single with a GOOD resonator (mentioned earlier) and a GOOD muffler.

 

i dont see how seperating them will create any more power at all, you want the exhaust to exit as quickly as possible. therefor.... sidepipes yo! (atleast if all you want is power)

 

As usual, you're right on the ball.
All of your points are valid.

In my case, I'll be going to be adding a supecharger to the car, at which point the exhaust will pay for itself.
The better flow characteristics will decrease restriction, as well, the low-end grunt will not be a problem...



Not for everyone tho...

 

If I didn't have to worry about the car being streetable, I'd go sidepipes in an instant...

 

yea that can change things a bit WOOOOT!

 

would it be better to merge the pipes and run a single or to have two pipes going straight back from the header?

 

Here is Paul Yaw's write-up on exhaust tuning...

http://www.yawpower.com/jantech.html
http://www.yawpower.com/febtech.html