Outer Limits 4x4 Board

Hey there I was out on the weekend with a mate who has a surf. He has removed his muffler and replaced it with just a straight through extension. He says he has gained a little more power in the bottom end and I was just wondering what problems would arise if I was to remove the muffler on my rodeo? I know it will be a lot more noisy but his was a fair bit more noisy still not excessive or anything. I have heard many cars and bikes much louder than his that are still legal. I am thinking it is illegal to remove the muffler also, this may vary from state to state, any thoughts on this anyway. I was just thinking it a cheap option to give it a little more power not that I really need it though. Would it burn out my valves by removing it due to the lack of back pressure? If anyone can help me out on this thanks
Tristan

i got a 2.8 turbo with no muffler it's not to noisy. If it's a non turbo it might be too noisy

Kool did you notice any power increases or anything I didnt think it would be too noisy. Mine is a 3.0L intercooled turbo so I think it will be fine removing it. I'm more concerned about any damage I may do to the engine such as burning out valves ect. I heard this could be a problem on some diesels that's all.

Removing muffler will be fine. You will get more boost slightly, and better response as the back pressure will reduce. Turbo motors work best with low as possible back pressure, as it allows the turbo to spool up quicker and more efficiently. But, why not just get a 2.5 or 3 inch exhaust made up with mo muffler. Much better thatn the holden garbage. Oh and just because it has plates, don't assume that the noise it makes is legal . Removing a muffler is not illegal as long as the noise level is still okay, but removing a catalitic converter is, as it is a emissions requirement.

Layto....

Cheers for that. That clears it up for me. i will remove it today then should take 2 seconds hehe. I am planning on getting a 2.5 or 3 inch exhaust in the very near future anyways. My mate was saying how his turbo spooled up much quicker now. So yeh Ill let ya know what it goes like when I remove it. Thanks heaps
Tristan

I removed the muffler and it aint too bad a bit noiser but when you get up speed and cruise she is still fairly quiet and by no means is it excessive in my eyes anyways. I reckon a quick dB test will let me know that I aint breaking noise restrictions which I highly doubt. I can hear my turbo,still barely but can hear it now and it seems to spool up around just under 2000 revs. The car seems to use lower revs at higher speeds too by around 250 revs. Next step will be to remove the crappy small exhaust and replace it with a 3 inch,funds permitting of course.

Phreaq wrote:I removed the muffler and it aint too bad a bit noiser but when you get up speed and cruise she is still fairly quiet and by no means is it excessive in my eyes anyways. I reckon a quick dB test will let me know that I aint breaking noise restrictions which I highly doubt. I can hear my turbo,still barely but can hear it now and it seems to spool up around just under 2000 revs. The car seems to use lower revs at higher speeds too by around 250 revs. Next step will be to remove the crappy small exhaust and replace it with a 3 inch,funds permitting of course.

Not possible to use less revs for speed, the revs vs speed are goverened by the gearing of the car. Nothing to do with exhaust.

Layto....

I understand that it is due to the gearing but it seriously has dropped 250 revs at the higher speeds. Before with the muffler on it was doing 3000 revs at 100km/hr with the muffler off its running at 2750 at 100kms/hr. I don't understand why it is myself because to me it doesnt make sense.

The only down side I found with removing the muffler on my turbo diesel is the noise gives me a hard on everytime i drive it

BJ

Haha yeh i like the rumble of it hehe.

Phreaq wrote:I understand that it is due to the gearing but it seriously has dropped 250 revs at the higher speeds. Before with the muffler on it was doing 3000 revs at 100km/hr with the muffler off its running at 2750 at 100kms/hr. I don't understand why it is myself because to me it doesnt make sense.

Basically, unless you have a slipping clutch, it is not possible. Maybe your tacho is not reading acuratley.

Layto....

Took the muffler out of my ra diesel and the only difference i noticed was it sounded better, i have not seen any improvement in fuel economy or felt any performace increase. Hope to have better results from 2.5" replacement system i'm gettin tho