What's the right muffler?

[Matt Holcomb]

Several months ago I sold my 3", single-outlet Monty so I could buy a single-outlet, OEM muffler. My mechanic recommended the swap as MFI engines are supposed to perform better with OEM mufflers and are easier to tune to boot.

Several months later, I remain unconvinced. My gut, my butt, and my ears all say that the car is restricted.

The engine is one of those crappy 911/83 things with measly 11.3:1 JE pistons and wimpy GE-60 cams.

Would my engine be better served with something like this?



If so, would it be cheaper to cut off the tailpipe, block the hole and add two straight tail-pipes, or sell the OEM muffler and buy a sport muffler?

Oh. Another option: I still have an old 3", single-outlet Monty with minimal baffling gathering dust in my Dad's shed. I had this muffler on the car until some of the baffling broke loose and created a severe blockage. Should I just send that muffler off and have it fixed and modified?

Edit: I forgot to mention that, according to Gus Pfister, my injectors need replacing. My car gets a bit breathless at 7,300rpm (it didn't when it exhaled through both Montys), and I'm wondering if it's because the recently rebuilt MFI is more demanding, or if the engine is restricted by the OEM muffler. I know that bad injectors mean that you visit the petrol station more frequently, but could the top-end breathlessness also be a symptom?


Matt Holcomb
MFIWDP
1974 911 Carrera 2.7 (RoW)
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[Adam]

Just un-block the old Monty. You had major flames happening with that thing fitted and the soud was fit to wake the dead!

If a baffle did break loose and block things up, it must have been that muffler's only one!

[Victor]

While we are all here - has anyone heard from Mad Merv?

[obrut]

Matt

Open up your old monty and do the triple 1+2 pipe thing. ie 1 open 2, capped for street and 2 open, 1 capped for track. I'm sure there's a few threads on how to do it lurking about. I spoke to a guy with this setup on a real 73 RS at classic adelaide last year - he was most happy with it. I think he said the single made slightly better low down torque whereas the double most better top end power (and noise)

Cheers - Ryan

[Adam]

While we are all here - has anyone heard from Mad Merv?

No, I've sent him emails and messages through ICQ, but he seems to have disappeared. He must be real busy with work.