Which Cat Bypass Pipe?

[Onefastman]

I am getting ready to buy a bypass pipe for my 3.2 and was wondering if there was any reason to go with a more expensive brand over OBX.

Any thoughts?

OBX CAT DELETE 75-89 PORSCHE 911 2.7L 3.0L 3.2L | eBay

[KNS]

I was looking for something quiet. I went with the M&K pre muffler because it does have some "muffling" properties. Along with my stock exhaust I've got a pretty quiet, low-key car.

[Andy911sc]

also interested in thoughts on this

[gtc]

The OBX stuff usually doesn't look so nice from the inside. Their collectors/junctions are poorly made. My fabspeed was much nicer, and the M&Ks I've seen look great as well (the M&K was not available when I bought the Fabspeed). A lot of people gripe about the Fabspeed taking the O2 signal from only one cylinder bank, but I don't think it's really that big of a deal. Mine worked fine.

[Onefastman]

My previous 3.2 had a Dansk sport one in two out.

If I ran a bypass (as opposed to a premuffler) and a stock one in one out exhaust how do you think the two would compare?

[gtc]

I think the cat + dansk sport would be louder than a bypass + stock muffler.

[Hydrocket]

Originally Posted by gtc

The OBX stuff usually doesn't look so nice from the inside. Their collectors/junctions are poorly made. My fabspeed was much nicer, and the M&Ks I've seen look great as well (the M&K was not available when I bought the Fabspeed). A lot of people gripe about the Fabspeed taking the O2 signal from only one cylinder bank, but I don't think it's really that big of a deal. Mine worked fine.

I suppose it depends. I know some of the older OBX stuff wasn't as nice, but their recent stuff is quite good. And the price is more than fair. I've handled one of those OBX pipes and the quality seemed perfectly fine.

I'd personally run an OBX on my car without worry.

[Jesse16]

I have the M&K Bypass from our host, nicely made and not very expensive. My car is louder, would probably have gone with the pre-muffler if chance to do again. Ben at M&K said both were similar loudness wise so ?? why does he sell both. I went with the less expensive option.
Went in easy.

[Dublinoh]

Originally Posted by KNS

I was looking for something quiet. I went with the M&K pre muffler because it does have some "muffling" properties. Along with my stock exhaust I've got a pretty quiet, low-key car.

This was my preference also with a M&K one in/two out muffler. Before I had a gutted cat that sounded metallic and loud to the level that I capped the drivers side exhaust. Now run both sides open with the pre muffler, not too loud but still sporty.

[McLovin]

I like the factory Euro premuffler.

[Oh Haha]

Originally Posted by McLovin

I like the factory Euro premuffler.

+1

This in addition to my Flo-Pro 1in/1out muffler makes great sounds.

[mclmk8d]

I also have an M&K per muffler with an M&K oNe-in two-out GT3 exhaust. Pretty loud but I love the rumble

[gamin]

M&K pre muffler and stock muffler on the 88. A little rumble and nice sound. Not too loud. But I'm an old guy and don't like loud noises anymore. And I never listen to the radio in the Porsches.

[suprxman]

I bought an OBX last year and it fit with no problems and was nicely polished.
Cost $89.00. Installed a new O2 sensor.
If it doesnt last I'll re-weld it.
Hooked to a Bursch muffler and all sounds great.
I'm well pleased considering the price difference.

IHMO for what it's worth.

[Aust87Carrera]

All this talk about bypass's - I decided I'd buy one. I then worked out I should get a proper jack support and while I'm at it a new 02....$$.

After buying all the goods and removing the Cat - I discovered the guts had been removed anyway. So the job came down to cosmetics and a fun hour tinkering with the car.

The package was wonderfully boxed - thanks PP

Some tips:
1. The Fab Speed bypass comes with gaskets and bolts/nuts - the bolts are a different hardness to OEM - not sure it matters but the length of the bolts do and 3 to 4 thread lengths to short (I'll replace the bolts when I fix the rocker gaskets/leak).
2. Remove the wheel (LR) - I didn't to start with and by the time I mucked around maneuvering myself to get a swing at some of the bolts....I simply came to the conclusion to remove the wheel anyway.
3. Consider an oil change (and rocker gasket) while your at it, with the cat out of the way things are easy to get to.

I have the following pictures.

[nineball]

dansk pre-muffler, stock muffler. sounds a little beefier under 2k, above it sounds like normal.

[mb911]

The one thing I can tell you for sure is only wish We could sell our bypasses and premufflers in the $89 range. We run off of a $60 an hour scale which is way light by todays fab standards and it takes waay longer then an hour to produce a part but thats what you get when you build them by hand and TIG weld them versus stamped and MIG welded.

[Arne2]

Originally Posted by nineball

dansk pre-muffler, stock muffler. sounds a little beefier under 2k, above it sounds like normal.

Same setup on mine, except my pre-muffler is an M&K. Pretty subtle sound, IMO. In fact, maybe too subtle. I'm still thinking about what might replace my stock muffler that might improve the sound but not be too loud for the neighbors and wife.

[Joe Bob]

Pulling the old cat and knocking out the catalyst is a lot cheaper option. It always amazes me how much people pay for 'Porsche' exhaust systems.

[Arne2]

Originally Posted by Joe Bob

Pulling the old cat and knocking out the catalyst is a lot cheaper option. It always amazes me how much people pay for 'Porsche' exhaust systems.

A pre-muffler or bypass has the advantage of being reversible, should that ever be desired.