BIG J MIXALOT

has anyone ever done it on a first gen before? i am thinking of doing it cause mine is all rusty.

d0 Luck

yes, i did. and i coupled it w/ a straight through dual muffler
it was LOUD... waaaayyyyy too loud. i didn't like it. but what you can do is run 2 presilencers then muffler. it should quiet it down a bit

reason for my 3" = upcoming bridgeport

Elysian

i had 3" on my last TII... straight pipe... i can only imagine how much louder it would be on a NA car... god...

steve84GS TII

http://img.photobucket.com/albums/v2...y/DSC01504.jpg

http://img.photobucket.com/albums/v2...y/DSC01487.jpg

http://img.photobucket.com/albums/v2...y/DSC01483.jpg

3" mandrel bent stainless.Light and rust proof,but $$$ to fabricate.

Its really not needed unless you are running a turbo. A 3" system on a N/A is just going to be loud and heavy,unless you need the flow(bridgeport,PP,ect)

Siraniko

iTrader: (13)

if ur running a n/a, 2.5 single is the ideal size as 3" is just way too big for street use. FYI: rb presilencer for 1st gen is way too small for a big ported motor. so use 2nd gen instead. flows much better.

d0 Luck

hey, where can i get mandrel bent piping done??

thanks!

BIG J MIXALOT

i am thinking of turboing my 12a and having 3" exaust steve84GS TII thanks for the pictures

RotaryRyan

Thats some serious stuff right there! looks good

web777

Are you using a Primaflow? I had 3" all the way down with 2 mufflers and it was too loud. I use a primaflow now which is quiet but I'm losing alot of top end.

Elysian

thats perty.... perty f*ckin big!

steve84GS TII

Big,yes....but it tucks in well and never scrapes.I run a RB TII presilencer as a main muffler when I want it loud(which is almost never),notice the 3 bolt flange at the muffler inlet.....its really loud,even with the cat and turbo.Turbos do kill noise but theres so much on a rotary its still just unbearable inside the cabin.

My quiet muffler,(and it is very quiet) is the RB Primaflow(Powerpulse,whatever) STREETPORT version.Its a bit louder than the standard RB muffler,but more importantly it has a 2.5" inlet.It was just a matter of taking a plasma cutter to the inlet and opening it up a bit to the full 3".Then weld on the flange and bolt it up.The inner baffles in the muffler split in two just after the inlet.It might be a little restrictive,but its still straight through,its very quiet,bulletproof and Ive been running 14psi through it no problem for years.

The local muffler shop got the pre-bent mandrel pieces and the straight runs from a steel place in the city.They actually stock mild steel mandrels,they had to order the stainless stuff.Shouldnt be too hard for any muffler shop to come by,especially one that does work on RV and semi exhausts.....

Rotor13B

Does it still have that RB raspiness sound?

cpt_gloval

iTrader: (1)

on the gray '83? stick to stock diameter piping. it only gets louder from there!

mortenf

For a NA car, there is absolutely no reason to go past 2,5". Running my streetported 13b 4port on a dyno, a 3" actually showed a decrease in power. All engines, the rotary included, needs a little bit of resistance to work properly.

Ditch the standard system though, and go for 2,5". Use stainless steel, and the biggest freeflow mufflers you can get fit. My system sounds tolerable under 3K, but i must admit it gets a little bit noisy after that... Much of witch relates to the way the pipes and mufflers are mounted.

steve84GS TII

Theres no rasp at all in my system.Its the standard, RB muted tone,that accompanied by a jet engines-like whoosh at full power.Inside the cabin you can hear the exhaust the whole time,but its just a light bass tone,no buzzing or resonance.

cpt_gloval

iTrader: (1)

i thought it was a matter of maintaining exhaust velocity to get the scavenging action goin' on.

steve84GS TII

Thats right,smaller piping will increase velocity and scavenging,to a point.When the backpressure becomes a hinderance to the escaping gasses,then youve gone too small.Its a balancing act between maintaining gas velocity,for scavenging effect(by not going too big)....and keeping backpressure from choking the engine off(from going too small)

The exception is with turbos.Bigger is better because they blend the exhaust pulses at the turbine,so scavenging and pulse tuning are pointless after the turbo.You just wanna releive the pressure on the backside of the turbine as quickly as possible by having a nice big exhaust system.