Muffler bypass or catback system?

[thefunkygibbon]

Hi all,

So i can get a muffler bypass on my Boxster S for about £250-300 or I can pay £400 and get a catback system.
Since i'm pretty new and green when it comes to cars and exhausts etc, i'm not sure what the differences would be. I'm guessing no power gains would be got from a catback... which would be better for sound improvements?

would I be better off saving my cash and spend closer to a grand for a full exhaust (manifolds back) system?

cheers

[particlewave]

Catback will be louder and sound a bit better, but most of the lower cost (and some of the higher cost) systems drone badly.
Bypass pipes won't sound quite as good, but still sound great and very little drone, if any.
Internal muffler bypass also sounds great and looks stock.

If you want to do the whole exhaust, you'll need to do the intake side as well before seeing any gains.
For sound only, I'd do the bypass.

[Keith Newby]

I went the bypass route and love it. $50 for the muffler and $450 for welding the bypass pipes and thermal coating. Perfect.

[Sveach756]

eBay catback for 200$ sounds great and takes 30mins to install.
Shawn

[tommy583]

Internal muffler bypass sounds better than a $200 cat back in my opinion. I've tried both. Plus the bypass looks stock and is cheaper.

[Finnegan]

Does anyone have a link to a diagram for the internal muffler bypass mod? I'd like to take something to show the muffler shop and see if they can do this.

[particlewave]

Originally Posted by Finnegan

Does anyone have a link to a diagram for the internal muffler bypass mod? I'd like to take something to show the muffler shop and see if they can do this.

Some info and pictures here:
Internal exhaust mod

[Finnegan]

Yes, thank you! That was the thread I was thinking of. I'm going to take that write-up and pics to a muffler shop here and see what they can do.

PW, you said,
"Though I do love it, if I did it again, I'd do a third 1" hole on each inlet. I wouldn't mind just a tad bit more."

Would a slightly larger bit have the same effect? 1.5" all the way through?

[particlewave]

3 x 1" holes = 2.355" sq. cross section (what I ended up with).

2 x 1.5" holes = 3.5325" sq.

So, two 1.5" holes on each side would be slightly more than a 2" bypass pipe. I think that would be fine.

[Finnegan]

Originally Posted by particlewave

3 x 1" holes = 2.355" sq. cross section (what I ended up with).

2 x 1.5" holes = 3.5325" sq.

So, two 1.5" holes on each side would be slightly more than a 2" bypass pipe. I think that would be fine.

Thanks, much appreciated!

[jmitro]

Originally Posted by Sveach756

eBay catback for 200$ sounds great and takes 30mins to install.
Shawn

that's what my 2.5L came with also. sounds good except it drones badly from 2300-2800rpm

[thefunkygibbon]

what is the definition of drones here? I fail to find any video on youtube highlighting it. is it just that you hear the exhaust note all the time rather than when you're flooring it? trying to work out if its a major issue or not. i've got the car booked in for a bypass modification so have given up on the idea of a chinese exhaust for now.

[particlewave]

Have you seen "Scanners"?
The scene when the guy's head explodes...that's what drone is like.

You can't really video it. It's a reverberation that rattles your eardrums and brain.

[Cunningr]

Its an annoying resonating frequency that can occur in the normal cruising rpm.

I bought a fvd brombacher sound version, design looks like a factory muffler, its stainless steel, a-lot lighter than oem. It has no drone, at 2k rpm its about 87db in my garage, blip rev peak was about 98 db. Expensive alternative, but highly recommended.