Does longer piping (118") boost low end or high RPM? Or shorter (113")
Im shooting for a Helmholtz resonance effect at around 5500 rpm with a half bridge

 

Shorter for high rpm, longer for low rpm. it just shifts the torque curve over left or right

 

So maybe somewhere in the middle? 115" primary? I have 2" runners. Should I collect to a 4"megaphone then 4 inch piping and muff. Or go to 2" , 2.5" 3"? Oooor 4"megaphone with 3" reverse cone at the end. I'm lost

 

the difference between 118 and 113 is pretty small, i'd just run whatever fit the chassis best, or even better make it adjustable

 

Agreed on the length - just make it fit the car.

As for individual runner length, over a long span such as that, it doesn't matter as much as it does on a short primary. So make the header runners a comfortable length(shape/angle) for you.

The collector can can begin as a 2.5" smashed down to 2" tall and about 3" wide. The length should be 6" per .5" diameter increase (like a megaphone) but I would only expand to 3", then into a final muffler with a 3" core. You might try a center/offset core muffler so the offset can absorb a little more noise without hurting flow noticeably.

 

What's your guys' take on butt welding tubes together.
I purchased a complete long primary road race exhaust but it had to but cut to smithereens to ship.
I doubt I can afford a presilencer and I'm trying to drive it by Halloween

 

no problem if done right, make sure the pipes match up perfectly, and use backing gas

 

Cool should be no biggie then. And plus I gotta weekend job that should help me out with buying more car parts

 

when i get around to doing mine, im going to use something like these to be able to try a few different lengths. JEGS Stainless Steel Lap Band Exhaust Clamps - JEGS

i'm on exhaust 2.0 and not only was it expensive, its also broken, so 3.0 is going to be simpler

 

That's a good idea. I'll hafta start over to do that. Mines collected at the muffler right now.
Kinda long but oh well

 

I had an old dynomax muffler welded up
It's long. And ghetto
I'm lookin for a 3" strait through muffler that is maybe like 10" round.
Basically as big as I can fit, then ill get better tubes bent
It's not to loud with the presilencer atleast
Haven't measured it yet, but its long
The collector is pretty much part of the muffler.
Ovaled it and has two 2" pipes into a 3" muffler

 

that system actually looks pretty good, its good enough you can go work on the intake/ecu.

i've been looking for an 8" round muffler forever, and the seem to be normal in japan, and AUS, but good luck finding one in the us!

 

How loud is that system? It looks really nice!

 

It wasn't too loud till I took it on the highway.
Muffler is blown out already and kills my brain it's so loud.
I'm lookin at huge strait through diesel mufflers.
Ill have a whole new rear section made when I get a new muffler.
Should I get a strait through style or the kind with the louvers that keep the sound down?
Too much backpressure for a half bridge?

 

I have heard great things about the flowmaster hushpower series. Might be something worth looking into

 

the engine will eat baffles, the exhaust pulses are supersonic, so its probably literally like taking a hammer to the insides of the muffler.

 

How about louveres?
Too much of a restriction?
I might end up getting two more resonators put in if I can't find a suitable muffler

 

Im using the HushPower 3in with the dump tip, I also have RB dual pre silencers and I love it! sounds deep and throaty...

 

I read about the hushpower on the improved touring website. It isn't your standard flowmaster 40 series . . .

 

No! not anything like the Flowmaster series... I talked to the Cheif design guy at HushPower and he stated that the HushPower mufflers with hold up to ovedr 2000 degrees and not blow out like flowMaster... They are built pretty well from what i can tell

 

Are you hush power guys running a bridgy?
How loud is it?
Any sound clips?

 

Im running a large street ported 13b with a RB Holley here is a sound clip
Pictures by mazdasandcoffee - Photobucket

 

Still sounds pretty loud tho eh.
Do you have a presilencer or resonators?

I wish I could find sumthin like the rotaflo mufflers.
US currency is crap and worth less than AUD.
So one rotaflow muffler would be $411.15 USD then add shipping from Australia .... not cool

 

Make your own muffler. Get the materials. Weld everything together. Can't be that hard. You'll save a ton of money and learn something too.

Here is a link to get you started.
3" Stainless Steel Tube Perforated Pipe Exhaust 0 25M Long Straight 76mm OD Perf | eBay

 

I would if I had a TIG
I was thinkin maybe I should just get a universal power pulse muffler
Seems like it would get the job done, especially if I get two more resonators
One for each tube before it collects at the muffler but after the presilencer

Apparently I have unequal length headers so I wanna try to put the two seperated resonators at equal lengths, so I guess they would look staggered slightly.
Would that even matter?