The dreaded raspiness!!!

[old_mr2]

Guys

We all laugh when we see a kitted up lancer or something plant it next to you and basically it goes no where and makes a terrible RRAAASSSSPPPPP noise

I recently upgraded my exhaust and NOW ITS HAPPENING TO ME

MY CAR IS TOO COOL it does not deserve a raspy exhaust. Its happening in 1st and 2nd only between 3000rpm and 6000rpm.

I am running a 4AGZE motor. some custom 4-1 extractors, 2.5 cat, 2.5 piping, a long muffler and 2.5 tip. Also i have a 175mm crank pulley. The car rumbles at low rpm and get louder as the rpm increases to a scream at high rpm.

Does anyone know what causes it?I thought it might be my cat converter. I got it for 20 bucks off ebay "2.5 inch Skyline cat"

Thanks in advance I have to get rid of it!!!!!

[-==L=a=N=c=E==-]

Put a resonator or mid muffler into the exhaust system. That should quieten it down a bit.

[old_mr2]

Thanks lance but i want to completely get rid of the raspiness, not just cover it up. I would like to know whats causing it so i can replace it or modify it. cheers

[Quinn]

The quality of your muffler could have a lot to do with it? just a thought.

[Xistant]

if you have a cannon get rid of it,

just whack a straight through pipe on da beast

[HAVABEER]

my exhaust sounds pretty raspy aswell. but mine has a "hot dog" and a oval muffler, think it does kind of boil down to what kind of muffler you have. sticking a cannon on the end of mine instead of the oval muffler would make a real differnce to the sound

[De@No]

yeh i also think it would have alot to do with the quality of the muffler.

[Hydra]

I've found that a turbo helps

My mates corolla w/ 20v has that raspiness... but it's got a ricey front bar too so it kinda works ok. He had a fairly big hotdog put on the exhaust which helped a bit but it still does it. I think it's a 2.25" system with a cat, hotdog, and lukey muffler.

I have a cat and lukey muffler and my car sounds good... but thats because the tiny turbos chop up the sound

[old_mr2]

Thanks guys
I dont have a hot dog or cannon. Its sort of a long truck muffler. Its on an aw11 so its an S shaped exhaust layout. I have a straight pipe out of the muffler.

[Yian]

Hrmmm, I would have put the raspiness down to either a hole/leak in the exhaust (but you said its a new system, so that rules it out).... or the exhaust rattling against something at certain rpms? A thought maybe?

[toaster]

i get this sound on my ae82 twincam with 2.25" tip (no other mods) (i bought it like that )

i dont mind it

[thechuckster]

you need some form of resonator before the muffler. the sharp exhaust sound has come from:
long runners for the extractors
CAT flowing too much
long resonant pipes
unbaffled or straight-thru muffler

you only want turbo mufflers with turbo engines (due primarily to ensure free gas flow). Check that the truck muffler i not just a perforated pipe running thru a long box.

You may need a resonator (hot dog) muffler prior to the muffler, this will take the bite out of the sound - the CAT will not do this for you.

Given the lack of room under the MR2, i'd suggest first replacing the unknown truck muffler with a proper non-straight-thu thing.

[feral4mr2]

exactly, a hot dog/resonator before the muffler should rid the horrid sound. the tech write-up in the Walker muffler book i read at work made coment on this.
walker do a few different lengths of resonator, look for a shorter muffler so you can fit them both in series along the back.

[o_man_ra23]

Look into fibreglass packed mufflers. They cost a little more, but have a much nicer sound than your usual muffs. Also, maybe change it to 2 1/4 from the back of the cat back... as 2.5 is a bit big for a 1600, even if it is supercharged. 2.5 should be fine for the cat tho.

Cheers, Owen

[feral4mr2]

lukey/walker make very good glass packed stainless mufflers.
http://www.lukey.com.au/tenneco/ULTRAFLO.HTM