Reducing Rasp
 

Is there a way to reduce rasp without taking away from the loudness of the system? Drone for me isn't that annoying but raspyness when accelerating is annoying and sounds like a fart can sometimes. My current setup is Revworks UEL, Perrin Overpipe, Invidia Catless FP, and Berk Dual Muffler Delete. I know this is an abnoxious setup right now but I like it minus the rasp. So what Im asking is what would reduce rasp the most? I was thinking about a 14" Magnaflow resonator in the muffler delete or getting a catted front pipe. What would reduce rasp the most but keep the same sound volume?

Thanks for your help

either should do the trick.

keeping the same sound volume would probably be a front pipe with a hemholtz resonator. any resonator in the front pipe would help but a regular resonator would reduce sound volume as well. You could also try an exhaust weight like what comes stock on some vehicles exhaust systems. google exhaust mass damper or resonance mass damper for more info and pictures of these. Also wrapping the header should help noticeably but not completely.

Add 2-3 resonators to the system, one in the front pipe, one mid, and even one in the catback portion. They don't have to be very large ones.

Isn't that a little overkill? Won't one be fine?

You won't know till you add one. With a muffler delete and everything catless, probably not.

+1

I have two resonators, a catted DP/OP and the stock header and my 3" exhaust is pretty damn loud still, but not raspy. I'll be adding a catless header soon and I still expect there to not be any rasp. My two resonators are about 15 inches long.

I think you will need at least two.

header is catless?

Get a catted front pipe and see if that helps. After that look at more resonators

Yes, catless revworks uel. I am thinking about for now just a 14" resonator on the catback portion and I will go from there.

It's an FA20, unless turbo I haven't heard one that isn't raspy yet....

Going turbo reduces rasp? Because it diverts alot of the exhaust gas to the turbo?? I was planning on the P-tuning turbo when it comes out anyway/

Turbo muffles exhaust really well. That's why 3" exhaust users are much quieter when the turbo is present.

I have Motiv Front pipe (catless) and Nameless axleback.
It doesn't rasp but drones a bit but not bad.
I believe usually whole bolts-on had catless, shouldnt rasp or drones. maybe i was wrong and this car is different than other cars.
keep us updated what you changed. i might get a header and dont want crazy rasp

There's lots that aren't raspy...

[ame="https://www.youtube.com/watch?v=WpavxOvyclc"]BRZ Drive By PERRIN Cat Back Exhaust & Front Pipe - YouTube[/ame]

can someone please define raspy for me?

If this: [ame="http://www.youtube.com/watch?v=Y18bo5IYE50"]86 TRD Griffon Concept 2nd test - YouTube[/ame] is raspy, then god damn me, I love it!!!

As someone who is running an FA20 cattled 4-1 header, nameless catted helmholtz frontpipe, and custom ft86 speedfactory V2 with varex muffler, i can tell you helmholtz does not eliminate rasp. My setup is too raspy for my taste even with 2 cats. I think LONG resonators are the key to reducing rasp.

OP, have you looked at the hks dual resonated front pipe? I assume you have the resonated Invidia front pipe?

I am completely catless at the moment. Headers and front pipe. I am considering putting in a 14" magnaflow muffler in the midpipe leading to the muffler delete

The farty noise in this is rasp:

[ame="http://www.youtube.com/watch?v=60Y9fRTidiI"]Exhaust raspy :( - YouTube[/ame]

[ame="http://www.youtube.com/watch?v=ZBdQZjRjzps"]Raspy ass Civic - YouTube[/ame]

So i think I will sell my berk muffler delete or install a muffler on the midpipe or get a Invidia N1 catback. How would the N1 sound vs. the berk muffler delete everything else being constant (same uel headers, catless fp, overpipe)

The least raspy/tinny/farty muffler I've heard so far has been the Perrin resonated catback. Everything else tends to sound high pitched, tinny (metallic tinging), or has that farty bark. I've got the Rev Works UEL in and it sounds great with the stock exhaust. I just need the full Perrin headerback, now.

Thats funny because im currently selling my 2.5" perrin catback. Check out the members section

Well the N1 is not loud compared to the berk muffler delete, so I am pretty sure the rasp will reduce by a lot.

Noise and rasp aren't the same thing, you can have a LOUD not raspy exhaust or a quieter but raspy exhaust. Typically the loud ones are raspy though.

I tried heatwrap and some hoseclamps a couple of days ago to stop the thin stainless steel pipe on my CBE from vibrating so much(causing the rapsy sound). Quite a noticeable difference. I'll be getting some more heatwrap to wrap near the muffler and a bit further up the CBE.
I would not try this with a NON stainless steel exhaust btw.
http://i41.tinypic.com/2vwbnt3.jpg

TIP: You can also get DEI stainless steel zip ties to secure the heat wrap, don't bother. Cheaper and easier to get/use hose clamps(just make sure they won't rust).

glad to hear that made some difference! im thinking about doing it eventualy on my J2 exhaust.

I have the N1 catback and just recieved my invidia catless resonated front pipe, will the resonator cut down the rasp?

I added a bit more heat wrap to the exhaust. Added some to the bends on the HKS muffler, quite a noticeable difference.
http://i39.tinypic.com/14kllxf.jpg
http://i44.tinypic.com/11w530x.jpg