View Full Version : custom exhaust???


sidewaysrx8
01-27-2008, 09:49 PM
hey guys i just had a custom exhaust put on the 8, but i have a few questions to ask...its a 3inch all the way back from the header (no cat)..and the didnt use a resonator, and its not that loud at all, but the type of muffler they used was one of those cylinder shaped ones and they put it about half way back under the car right before it splits off in to the y pipe...i wanted to know if i could be loosing hp with this type of set up, and i got 3 inch piping only cause i read all the exhausts except greddy are 3 inch....the muffler actually looks like a resonator but its not, and when i let my friend drive it next to me at wot, it sounds like a damn jet engine (you dont even hear the exhaust it just sounds like its blowing a ton of air, kinda wierd)....

nmarz77
01-27-2008, 09:56 PM
Sound clip?

sidewaysrx8
01-27-2008, 10:00 PM
not yet, kind of sounds like a srt4 at wide open throttle, i thought it would be loud and obnoxious but it sounds so different

nmarz77
01-27-2008, 10:04 PM
Nice!!! I actually have always liked the ways those sound. I think they have one of the best sounding factory exhausts for a four cylinder. If you get around to it a audio or video clip would be nice!

NgoRX8
01-27-2008, 10:04 PM
pics too

sidewaysrx8
01-27-2008, 10:05 PM
so do you think that this type of exhaust is making me lose power???

nmarz77
01-27-2008, 10:07 PM
That's hard to say. Just because it's quieter than expected doesn't mean your losing power. If it sounds like a SRT4 then it can't be too quiet.

sidewaysrx8
01-27-2008, 10:10 PM
pics too


i will post them eventually but for now just try to picture 3 inch piping with a single muffler right in the middle ( like right under the rear seats is where the muffler is) then a y pipe that splits off leading to the 4 inch tips...just want to see if it flows better than stock,,,,

sidewaysrx8
01-27-2008, 10:11 PM
That's hard to say. Just because it's quieter than expected doesn't mean your losing power. If it sounds like a SRT4 then it can't be too quiet.

hahah naw its loud but non ricey, just sounds like a jet taking off

nmarz77
01-27-2008, 10:11 PM
Well the only way you're gonna know for sure is with a before and after dyno run.

sidewaysrx8
01-27-2008, 10:13 PM
3 inch isnt to big though right

nmarz77
01-27-2008, 10:14 PM
Nah, it should be ok. There are plenty of guys on here running N/A with 3"

sidewaysrx8
01-27-2008, 10:19 PM
Nah, it should be ok. There are plenty of guys on here running N/A with 3"

and what about if the muffler is further towards the front of the car then stock, (sits right under the rear seat)

nmarz77
01-27-2008, 10:44 PM
I wouldn't worry too much about it unless it's causing interference or excessive heat with anything. You never know.....your exhaust may be superior to all the others.

Jeromie
01-28-2008, 11:31 AM
ive messed with my exhaust quite a few times and it sounds like u should ask the people who put in what the inside of that muffler thing looks like. when i had the same setup to a single exhaust it was the best sounding exhaust ive ever heard! the problem was i had the same feeling as u so i had another shop pull the piece out... turned out to be a resonator with a 1" pipe inside! an rx8 with 3" pipe and no cat will almost always be rediculously loud and annoying. i think somthing gotta be wrong i.m.o.

sidewaysrx8
01-29-2008, 06:38 AM
ive messed with my exhaust quite a few times and it sounds like u should ask the people who put in what the inside of that muffler thing looks like. when i had the same setup to a single exhaust it was the best sounding exhaust ive ever heard! the problem was i had the same feeling as u so i had another shop pull the piece out... turned out to be a resonator with a 1" pipe inside! an rx8 with 3" pipe and no cat will almost always be rediculously loud and annoying. i think somthing gotta be wrong i.m.o.

its funny cause it looks just like a resonator...will going from 2.5 inch to 3 inch cause me to loose hp, if im still n/a????

tiltmode43
01-29-2008, 07:37 AM
You'll noticeably lose torque in the low end but gain up high - I'm running 3" test pipe + 3" single exit exhaust

mysql101
01-29-2008, 07:41 AM
be wary. Most 3" exhausts for the rx8 are designed to bolt up to the oem midpipe/cat which is a 2.5" pipe. So unless both your exhaust and midpipe are 3" AS WELL as the connection points, all you're doing is increasing surface area in the catback which will slow down and cool the air before it exits the car.

staticlag
01-29-2008, 11:02 AM
be wary. Most 3" exhausts for the rx8 are designed to bolt up to the oem midpipe/cat which is a 2.5" pipe. So unless both your exhaust and midpipe are 3" AS WELL as the connection points, all you're doing is increasing surface area in the catback which will slow down and cool the air before it exits the car.

what size is the pipe coming off the manifold? 2.5"? I've never measured it :(

Probably best to do 3" V band clamps like Teamrx8.

Jeromie
01-29-2008, 01:16 PM
its funny cause it looks just like a resonator...will going from 2.5 inch to 3 inch cause me to loose hp, if im still n/a????

exactly. my piece looked like a resonator going from 3" to 4" but inside the 4" case was a 1" pipe! it did a great job of absorbing the sound, at the cost of losing high end power....

sidewaysrx8
01-29-2008, 05:35 PM
exactly. my piece looked like a resonator going from 3" to 4" but inside the 4" case was a 1" pipe! it did a great job of absorbing the sound, at the cost of losing high end power....

yup that was the problem, talked to the guy at the shop, and shure enough the muffler used was a walker muffler with a inner diameter of 1.5 inches....so tomorow im getting it replaced with a 3 inch straight threw magnaflow cylinder type muffler to go in place of the old one..yes i know its gonna be loud but i want my power back, and yes its 3 inch all the way back..ill post pics.

sidewaysrx8
01-29-2008, 05:37 PM
You'll noticeably lose torque in the low end but gain up high - I'm running 3" test pipe + 3" single exit exhaust

really? cause right now it feel like i have no top end but more low end, must be the small ass muffler..

nmarz77
01-29-2008, 05:45 PM
You would have to be losing/gaining a lot of power to even feel anything with your butt dyno.

sidewaysrx8
01-29-2008, 06:07 PM
You would have to be losing/gaining a lot of power to even feel anything with your butt dyno.

well i wasnt sure untill i tried some top end runs and it took me foreever to hit 120mph, not to mention i barly beat a new 2 door bolt on hemi powerd ram

sidewaysrx8
01-29-2008, 06:07 PM
y pipe leading to the tips

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05207.jpg

sidewaysrx8
01-29-2008, 06:08 PM
y pipe leading to the muffler

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05203.jpg

sidewaysrx8
01-29-2008, 06:10 PM
the muffler..

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05206.jpg

sidewaysrx8
01-29-2008, 06:11 PM
the muffler again

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05204.jpg

sidewaysrx8
01-29-2008, 06:12 PM
midpipe..

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05205.jpg

nmarz77
01-29-2008, 06:12 PM
well i wasnt sure untill i tried some top end runs and it took me foreever to hit 120mph, not to mention i barly beat a new 2 door bolt on hemi powerd ram

Wow I'm surprised you beat one of those! I get rolled by them daily! :lol:

sidewaysrx8
01-29-2008, 06:13 PM
another one of the y-pipe

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05202.jpg

http://i6.photobucket.com/albums/y215/DetroitRaceChic/DSC05201.jpg

nelsonrx8
01-29-2008, 06:24 PM
sound??????

sidewaysrx8
01-29-2008, 06:25 PM
sound??????

going to take a vid now

balefire
01-29-2008, 06:44 PM
Is all your tubing mandrel bent?

TeamRX8
01-29-2008, 06:56 PM
lol, copy cat

sidewaysrx8
01-30-2008, 09:56 AM
yes all manderal bent....why do u say copycat

TeamRX8
01-30-2008, 03:42 PM
I was joking, but here's the reference:

http://www.rx8club.com/showthread.php?t=135874

I'm sure yours weighs 3x more ....

sidewaysrx8
01-30-2008, 08:08 PM
ok well i got the exhaust redone, much better flow the old muffler that was on the car had a inner diameter of 1 inch!!...so my car pulls much better with the 3 inch straight threw race muffler, only problem is its way way way to loud, thinking about going with the agency power exhaust off ebay for 700$, any comments on this exhaust or better pricing please let me know

TeamRX8
01-30-2008, 08:39 PM
lol ...

Jeromie
01-30-2008, 09:50 PM
that irritates me soo bad! y would i go to a muffler shop and ask for 3" piping for them to only put a 1" resonator?!?!?!?! stupid shops :icon_no2:
i knew that was the problem...

sidewaysrx8
01-31-2008, 10:32 AM
that irritates me soo bad! y would i go to a muffler shop and ask for 3" piping for them to only put a 1" resonator?!?!?!?! stupid shops :icon_no2:
i knew that was the problem...

lol im still pretty pissed about it as well, i cant notice a good difference especially top end, but i just ordered the agency power exhaust, becacuse the noise is killing me and everyone else...lol

tiltmode43
01-31-2008, 10:39 AM
really? cause right now it feel like i have no top end but more low end, must be the small ass muffler..

Yeah, the muffler was causing too much backpressure helping you down low hurting you up high.

imo losing torque in this torque sensative car is very noticeable, especially if you live in a hilly area.

tiltmode43
01-31-2008, 10:42 AM
Already ordered? Agency Power is going to be pretty loud too, there's not cat there either. If you want to be quiet yet catless check out the mazsport double resonated pipe.

BTW I realized I don't feel too guilty not running a cat considering the low NOx emissions of our cars by nature in combination with all other cars getting higher mileage.