error402

I'm pretty sure this has been asked before, but I'm too lazy this morning to do a search.

Okay here it the question. What's the differences in presilencers from different companies, and is there a noticable sound reduction? Any recommendations from anyone?

Right now I have my exhast straight piped, which sounds like a buzzing bee when reving the engine. Is this because of the crappy monzda muffler I have or just because of the high compression from the exhast?
I was thinking about a Flow Master muffler, but I'm unsure if the sound will change. I want to keep the exhast free flowing without any restriction. (no emission laws in KS, woo hoo!) I would like to have a nice low rumble sound. So, I don't have to worry about the police pulling me over for excessive noise, and I feel pretty bad in the morning when I start my car for my neighbors, because my 7 is LOUD.

peejay

It's the muffler.

Every car I've heard with the complete RB exhaust (their header and presilencer and muffler) sounded like a weedwhacker. Very quiet, very soft, very high pitched.

I had a header and a SS muffler (2" in/2" single out) on theone car, it was very harsh, mildly loud, and high pitched but it didn't have THAT much bass to it. Just the way I liked it.

http://www.geocities.com/izzmus/evilengine.html Go to the bottom and click on "drivin' around cold"... that's what it sounds like with just a header and the stock muffler.

Basically the presilenser takes away the harshness... it makes it sound less like a rotary (aka chainsaw on Crack) and more like a Honda with a fart-cannon.

error402

I don't want to sound like that.

So, it's the muffler that is causing the buzzing sound?

FuLLsMoKe

Well... I have a full street port RB exhaust... It DOES NOT sounds like a weedwhacker

It is noticibly louder than the stock exhaust and has a low tone to it--when you shift a little early, the whole car will rattle because of such a low tone (like a low and pretty loud rumble)--I've had people who don't know the difference between a rotary engine and a piston engine say: "Geez! How BIG is that engine?!"

Maybe their cars had the cheaper or not street port exhaust...

sbrx7

You might want to reconsider the Flowmaster though. I have a buddy with a header, 2 1/4 pipe back to a flowmaster and it is godawful loud. We laugh at it now, but he's going to run the car in CSP this year in
solo 2 and I doubt it will pass our 95 dB limit. I doubt it will even be close as a matter of fact.

My .02

Steve Bertok
94 MB touring
85 GSL-SE
88 'Vert

Nick-7

Does the RB street port exhaust work on non-street ported engines.

Or is that just the name

FuLLsMoKe

It is recommended for a street port engine, but still functions optimally on a non-street ported engine, Nick-7...

My 3 billion dollars...

Felix Wankel

My Street Port exhaust is low pitched as hell. No weedwhacker or fart cannon sound.

Hey fullsmoke, my gf is from Huntsville. We'll probably be up there in the next couple weeks

FuLLsMoKe

Really?! That's awesome... I might get to meet a "Boostaholic Moderator"!!!

Yea... and I love my RB exhaust system... It's just too bad that I can't race my 7 as a muscle car, though it sounds like one

Felix Wankel

If I ever get around to fixing my 85, I can drive it up there.

FuLLsMoKe

Don't disappoint me

just kidding

error402

so what am i looking at here. a RB header and a flowmaster? LOL
hell, sounds good to me.

FuLLsMoKe

hehe, sorry, back to the topic...

the pre-silencers are used because a rotary engine is MUCH louder than a conventional 4 cyl. engine... i've never heard of any other brands making pre-silencers (cuz i trust RB with their products)... plus--the rotary engine runs almost twice as hot as a normal 4 cyl--thus if you buy something that's "ultra lightweight" that has a thin wall/weaker material the rotary heat will eat it up... RB may cost more, but they have done lots of studies on the rotaries and, i for one, trust RB and am willing to pay extra to have something that i know will last longer and help my 7 go faster

error402

okay so does the RB header replace any of the stock cats? if so that sucks, because i have the straigh pipe connected to the stock header, which means i have to cut some of the straight piping off. d'oh just more work. if it just replaces the stock header that would be awsome.

if the RB header works out. then i'll get the header and presilencer, from RB and the flowmaster muffler from the local welding shop here that did my straight pipe.

Felix Wankel

RB headers will not fit on any cat replacement pipes. A header is much longer than an exhaust manifold.

Funny how no one ever belives me when I tell them this

RXcetera

Haha, I beleive you.

There's no point in getting only half the RB setups. The Primaflow (RB) muffler does most of the quieting job. Wether you use the long or short primary system, dont overlook the RB muffler... you'll regret it.

BTW, both RB systems offer incredible power gains on stockport motors. I've had both and there are some pretty important differences between them. The short primary setup is a little louder. You can here the pulses better through it and it's tone isnt as low as the long primary setup (street port). It seems to flow faster than the long primary setup (rpms climb faster). Its sweet spot (where the power really comes in) is around 5000rpm.

The long primary (street port) setup is quieter and much more mellow sounding. The sound it makes is nice but kinda strange because you get stereo pulses that arent always coordinated. This setup really improves your low rpm drivability... power comes on at a much lower 4000rpm. The streetport setup is faster than the short primary setup, but it somehow feels somewhat slower. I think the diminished noise has something to do with it.

I picked the streetport .

SpeedRacer

Yep, thats what I'm going through now. I had my Bonez racepipe on for well over a year. Just put headers on my car, and had to gut my old cat and stick that on. I'm gonna get the presilencer part of the racepipe cutoff, and have flanges welded on, and use that as a straightpipe from my headers to y-pipe. I have the Racing Beat Dual outlet headers also, just not enough cash to fabricate a full dual setup right now.

jsinrx7

The velocity of the rotaries exhaust pulses is why it is so hard to keep quite, the velocity is twice that of a typical boinger, so if you want a quite/non chainsaw sounding exhaust, your going to have to sacrifice the free-flow with more back-pressure. The Primaflows kick-***, but stay away from pace setters, unless you dont like your neighbors! Jason

FuLLsMoKe

You can reduce noise be combining the pulses together... or visversa...

To combine pulses, have the exhaust ports combine into one pipe... This will make the pulses "balance" each other out and thus make it quieter and smoother sounding...
To make louder, have the exhaust ports run in their own pipes...

hanman

I have the RB header and presilencer. I can't imagine how loud it would be without the presilencer, certainly loud enough to get the attention of the Topeka Police Department. BTW, I also have the Monza muffler, a little loud but not real bad.
Error, If you want you can come to Topeka and give a listen.
hanman

error402

hey hanman sure thing where in topeka are you? i only know one other rotor head where i live and he's my next door neighbor with a 88TII Anny. Edition.

hanman

I work at the hotel connected to the Expo Center. Drop by some afternoon if you see the black first gen out in the lot. It is usually parked out by itself. After 4K in body and paint, I don't think I could take a door ding.
hanman