Exhaust Help: Just Put New Muffler In But....

YOUWSH · 06-22-07, 06:55 PM

I just changed my muffler yesterday to a more "quiter" one. Previously I was running a 3 inch cat back with dp and for three years I put up with the loud drones of the car at idle and whilst driving. Enough was enough.

I got them to just cut off the cannon style muffler and fit one similar to the racing beat shape, 3inch through with larger baffle area and dual tips. After the install the car was dead quiet even at idle and if anything it felt extremely strange to be able to hear yourself whilst driving with the stereo off. Now for the questions:

1) After taking her for a drive I notice at WOT the car now lost 1psi of power. Before the install the boost controller setting would give me 0.83 bars but now I'm reading exactly 0.73 bars. Should I be worried or simply turn up the boost controller to compensate?

2) At WOT I can hear the engines screaming but only muffled sound coming out from the exhaust as if its struggling. If I can relate this sound to anything else it would like slapping a silencer on a cannon style muffler. So my question is even wtih the exhausting sounding like so, the exhaust is still able to flow freely out the muffler but minus the sound?

Thanks everyone

YOUWSH · 06-22-07, 08:13 PM

Some photos to top it off.

Silver7 · 06-22-07, 08:53 PM

It sounds to me that your new muffler is simply more restrictive than your previous muffler since it is much quieter than your previous exhaust and the fact that you lost one PSI of boost. I have an Apex N1 dual and swapped it out with a friend's RB dual tip catback. The RB was quieter but I lost 0.5 to 1 psi of boost. You can turn your boost back up some, but you probably won't be flowing as much air through the engine than you did with your old exhaust therefore you may be down a few HP. Not a big deal since it sounds like you are enjoying the decreased noise level of this new exhaust.

YOUWSH · 06-23-07, 01:18 AM

Oh I see that makes sense. I was loosing sleep last night thinking I had made the wrong decision. So in other words for the car to perform this doesnt necessarily mean the car has to be loud?

Monkman33 · 06-23-07, 01:30 AM

restrictive exhaust will absorb a little power, but if you are not really into getting every inch out of every yardstick you purchase, then enjoy the quieter ride and turn the boost back up to 10psi. it will still be better than stock.

1QWIK7 · 06-23-07, 01:48 AM

Yeah that pretty much sums it up.

Less restrictive exhaust = noise & hp

You cant have one and not the other.

So basically you sacrificed some hp just to have a tolerable sound. Which is not your fault because our cars are pretty loud with an open exhaust.

BTW, that exhaust looks awesome. I wish a company offered an exhaust that looks exactly like that. The RB duals is close but still, i think yours looks better than that.