Muffler Delete on a Mazda 6 MPS

[High on PSI]

I removed the passenger side muffler today, left the driver side muffler on.
It sounds so good. I'm not even joking, and it's not ridiculously loud.

http://www.youtube.com/watch?v=VrFeiUgBOAU

BUT

I feel like I've lost power? Not sure about 1st and 2nd gear, but in 3rd gear I just don't get the stuck to my seat feeling anymore... I have heard that sometimes running no muffler will make you lose power, but I've YouTubed MS6 no muffler, Mazdaspeed 6 muffler delete etc. and have searched on other forums and there's nothing bad said. Also one thing I've noticed that is quite funny... is that when I turn the ignition to start my car it starts STRAIGHT away now, doesn't take a few seconds like it used to

Any idea why it feels like I've lost power? Will going to an exhaust shop and having a straight pipe done on it bring my car back to normal but also keep most of the grunt it makes now?

[bd581]

Cars need back pressure to run. Remove that and they don't go well. Especially at low RPM. Although in turbo cars its not as important as a naturally asperated engine. Its a fine line between flow and back pressure in an exhaust.
Also when running twin exhausts, its important that the exhaust flow is balanced, equal flow in both sides. You have taken that away by removing one muffler.

[High on PSI]

Okay so will removing both, and replacing them with straight pipes keep equivalent power and give me the grunt I want. As in no gain or loss.

[bd581]

You'll get noise.
And if you subscribe to my theory of 1db gain = 5kw gain, you'll get lots of grunt

[High on PSI]

Lol, I feel kind of stupid right now. Had a big night.
So when I stick the straight pipes on I'm going to go back to the cars normal state (when both mufflers were on) and maybe have some gain?
Keep in mind I have a Mazda 6 MPS!

[bd581]

You'll get noise and little if any proper power gain.
Change the T piece to a Y piece before the muffler, thats about the only place you'll get actual gains when your talking about after the cat.
Before the cat is where the actual gains are to be made

[High on PSI]

I'm not after gains as of now and only trying to make my car a little louder. I did remove the other muffler just before to see how it would run, I felt a whole lot of difference from last night driving with only one muffler removed. 3rd gear actually feels stronger than with both mufflers on but 4th gear... meh.

Will go and get straight pipes put on tomorrow and see how it goes

[High on PSI]

Does $250 for the 2 sound like a reasonable price?

[Rayd]

Does $250 for the 2 sound like a reasonable price?

Mate that's a jip, I'll weld those two bad boys on for you, takes 5 minutes.

May aswell get the whole catback done , won't be more than $700-800 I dont think for custom catback

[High on PSI]

Come to Perth and do it for me then please!
I would do it if I knew the right measurements for the pipes etc. Also need mandrel bends and mounting brackets and connecting flanges too

---------- Post added at 02:36 PM ---------- Previous post was at 01:17 PM ----------



Is this safe to do? I can feel that its still flowing through the muffler but it also has the noise I want.

[MattMPS3]

Ummm, no not very safe, your car might sound cool, but it wont look cool when it is engulfed in flames, or you start melting stuff....so where is the fuel tank located on the 6 anyway?

[High on PSI]

I really have no idea but there is nothing near thoughs pipes

---------- Post added at 03:00 PM ---------- Previous post was at 02:59 PM ----------

I'll probably put it back to normal.. "engulfed in flames" sounds scary as shit lol. How will straight pipes prevent this? It would still be hot wouldn't it?

[MattMPS3]

Straight pipes if anything would run cooler as the exhaust gasses aren't hanging around in a muffler so to speak, the big gaps you have in your pic there are the issue, that plastic under tray stands no chance if you leave it.

[MZSPD6]

I had a custom catback installed, it was built with a nice Y split before the rear diff and the pipes went either side of the rear diff in to a set of offset straight through boxes.
Great noise and about a 5kw gain.

After I installed the down pipe and 100 cell cat I gained about 20kws more and the exhaust is only slightly louder than the cutback only was.

[Rayd]

I had a custom catback installed, it was built with a nice Y split before the rear diff and the pipes went either side of the rear diff in to a set of offset straight through boxes.
Great noise and about a 5kw gain.

After I installed the down pipe and 100 cell cat I gained about 20kws more and the exhaust is only slightly louder than the cutback only was.

Wow, I have the exact same story, lol go figure!

[High on PSI]

Going to try find the measurements and go buy the pipes myself and do the job myself lol. Just going to cut off the stock muffler flanges and use them

Btw the exhaust isn't very hot to touch after 20km+ of driving, driving normal and gunning it alot of the time too.

[Rayd]

Going to try find the measurements and go buy the pipes myself and do the job myself lol. Just going to cut off the stock muffler flanges and use them

Btw the exhaust isn't very hot to touch after 20km+ of driving, driving normal and gunning it alot of the time too.

In before DIY fail

[High on PSI]

What size is the piping on our exhaust / muffler?

[High on PSI]

Btw, this is what it sounds like...http://www.youtube.com/watch?v=VrFeiUgBOAU

[Doug_MPS6]

I've been away and I come back to read threads like this. I've decided not to mince my words any longer....

I don't think I've ever heard of or seen any idea so dopey as removing one muffler in a twin system and leaving the other one in place, except what I see in the later photos of inserted spacers in the tailpipe pipe flanges which is about as nutty as I've come across in a long while.

Apart from being dangerous from a fire issue, there is also potential for carbon monoxide ingress into the cabin space; it is mechanical vandalism of the 1st order that no car, far less a fine one such as the MPS6, should ever be subjected to. Such modifications lower the entire "tone of the neighborhood" of genuine enthusiasts who truly care for their cars, and should be strenuously discouraged. It's a shame that these cars are now becoming so cheap that some folks with more money than sense can get their hands on them and do this sort of thing to them.

And in my view, lots of noise usually just says "look at me - I have no idea what I'm doing and it's no doubt stuffing my car up and lowering the resale value but doesn't it sound great".

There seems little point in adding noise if it isn't associated with some genuine power benefit.