??? 3.2 w/ cat bypass + M&K

[widgeon13]

I have an 84 Carrera (stock 3.2) with a chip installed by the previous owner. Not sure of the origin of the chip. The car performs as you would expect and runs smoothly since I have owned it over the last six months. It presently has a 1 in 2 out jury rigged muffler (second outlet welded on by PO) and I am interested in installing a cat pipe bypass and M&K 1 in 2 out. I have done a search and could not find this specific setup. I was interested in comments on this particular combination, what is the most efficient cat pipe? I would prefer SS pipe. Does anyone have pics that would show what this plumbing looks like. Info from postings indicate this will not give any added power but may improve low end torque. Any other comments.
Thanks

[ThePointman]

I hear that the Fabspeed combo is a nice setup (Fabspeed cat by-pass and Fabspeed muffler). Though I am not sure that it matters all that much what you use just that you get the catalytic converter out of the picture. I just installed a cheap cat by-pass on my car and the now the pickup from about 2000rpm is very responsive. It used to be more around 3000 - 3500 before the pickup was really quick but not now. I know my car has a chip yet I do not know what kind or how the car was tuned when the chip was installed. Having the O2 sensor unplugged seems to make the car idle smooth as silk now too. Anyway if I had unlimited money I think I would get SSI's, a fabspeed cat by-pass and an M&K 2 in 2 out muffler.

Here is what my cheapo solution looks like:

[kilodawg]

About all I can say is that I'm on the same path as we speak. I'm going with a Steve Wong chip, a Fabspeed catbypass and the M&K 1 in 1 out setup. All sourced from Pelican. Curious to here other comments but from my searching this seems to be a solid option when cosidering cost and weight as significant factors.

[lvporschepilot]

Regardless of the brand of bypass pipe, you must make sure you have adequate fuel mixture in the combustion chamber to optimise the fact that your vehicle is able to expel gases much more effitiently with the bypass. I recommend installing a cone filter with the bypass pipe if you have not already done so, just so the increase in exhailing can be optimised with an increase of inhailing. This is why Steve Wong has a specific chip for vehicles with a bypass and without a bypass. As long as your mixture is optimised at higher rpm's with the bypass, I really do not believe it matters which pipe you chose to install. They all have one purpose and that is to release backpressure. They all do is pretty close to teh same amount but, without the correct fuel mixture they are all not going to do much. Get your car on a dyno that can also read your mixture readings at optimal bhp rpm's. Install the cat bypass and see how that affects the mixture, then compensate with a different chip to take advantage of the increase in exhaust flow.

My car for instance was already running rich at higher rpm's for some reason so, when I installed the bypass, no chip upgrade was needed. It was already very well optimized. By getting your car on the dyno and measureing the mixture, you might save a bunch of loot on a new chip.

good luck! John

[KCinBR]

About 2 months ago I installed a Fabspeed pre-muff and M&K 1 in 1 out on my 88 Carrera 3.2, also had Steve Wong upgrade my Chip.
The results are very good. overall driveability is much improved, escecially in the lower Rpm ranges........and Oh does that M&K sound good.
I talked to Ben at M&K before my purchase and he told me that the 2 out muffler probably would not help performance but would make it louder.
Here is a couple of pics taken during the install:

[widgeon13]

Thanks for the feedback from everyone. KCinBR, I would go with the 1in1 out but already have the rear valence cut for the existing exhaust and really don't want to put new valence on nor do I want to .run w/o valence. The Fabspeed cat bypass looks very nice and goes well with the M&K. I think that is what I will do myself.

[kilodawg]

KCinBR,

Just a question since I'm going the exact same route. No O2 sensor?

[widgeon13]

The fabspeed cat pipe does have an 02 sensor, you can see it in the promo pics but not on the pics posted.

[KCinBR]

Yes I do run an O2 sensor, but I guess when the pics were taken it was not yet installed.........gotta get a new photographer

[ThePointman]

I do not run an O2 sensor the wires visible in my pic are now no longer there and I the car will be in the shop for fuel/air mixture adjustment next week. It is so nice living in a place where there is no emissions testing.