Cat bypass on stock 3.2 muffler
 

Was planning to pick up a cat bypass for my '87, but was not sure if I would install a sport muffler or not. Can anyone comment on the sound level with a cat delete and stock muffler? Any louder? Rev better?

Thanks

That's my set up on an 87.

Slightly louder.

Butt Dyno can't feel any difference.

Heat level under the car is reduced.

Removes a little weight.

I couldn't tell much difference when I changed the cat to a M&K pre-muffler, except it was a lot prettier.

Then I changed the stock muffler to a M&K sport 1 in 2 out. Wow.

a cat-delete pipe is different from a pre-muffler set up, say from M&K. the cat-delete pipes are simply straight pipe that produces a sound not as pleasing as the pre-muffler, no matter what you bolt on behind it. i'm only mentioning this because the OP mentioned a cat-delete pipe.

I have a cat delete pipe and as far as I know the muffler is stock. It has a nice high end growl. I'm gutting a stock muffler to add to sound on the low end and probably make it growl a little more on the high end. The only problem that I have is a popping sound going up through the gears under heavy throttle. I'm working with a chip maker to sort it our. According to Steve Wong, the only way to fix the popping is to have a chip designed for your setup.

Hope this helps.

The PO had a bypass and an M&K muffler installed. I don't know what mine used to sound like but I have heard others, and I like the way mine sounds.

Any sound clips?
Would love to hear your set up.

I have the M&K pre muffler with the stock muffler on my 86. The butt dyno says we are faster but nothing documented. Sound wise the car is actually a bit quieter then stock with the cat. At 2800Rpm there is a very nice low tone rumble that I love hearing.

My goal would be to raise the volume on the low tone rumble but have no good sound clips on mufflers out there. Ideally I'd like to got to the M&K 1 in 1 out but need to hear it before I pull that trigger .....

+1 to this.

Sure, I'll get one and try to upload tomorrow.

As requested:
911 Porsche 3.2 muffler sound bite --> 911 Porsche 3.2 muffler sound bite - YouTube

Apologies as this is my first youtube u/l.
let me know if I should take from another angle.
previewing on the phone sounded tinny.
previewing on the net sounded too bassy.

hth,
Dan

Excellent Dan! Sounds great. Bass is better for me if that is the reality. The clip you made sounds split on my sounds system here, more growly.

Thats great. I'll listen to it about 50 more times.
Thanks you for posting...
Looks like I'm now closer to spending $625...

Thanks - I mentioned in a PM to you that the recording sounded a little saturated/clipped, but it is low sounding. My wife says she can hear me a block or 2 away, and I try to keep it to 25 mph in the 'hood.
I really bother to listen to the radio.
It is not as wide open as the sound on the fabspeed site with their clip of a 3.2 cat and muffler bypass. (no affiliation) 5 years and no neighbor complaints.
I will try another recording this weekend to see if I get one that is more faithful.
Hopefully the OP can use this info too.

what did you use to record that sound clip? the sound isn't bad, but your exhaust sounds a bit tinnier/raspier than mine and i'm running the M&K bypass and M&K 'motorsport' 1in/1out. i really need to get a good sound clip of mine, but the device used and on what system the clip is listening to has such a bearing on the sound, you never know what it will sound like on the other end. mine is definitely a deeper, bassy sound - at least from what i hear of yours online and mine in person.

sbeebe,

M&K cat bypass or M&K Pre Muffler?
More clips are great...hope Brian knows your doing his work for him....

i'm running an M&K pre-muffler. you can check out this thread about my conversion from one system to the other and my findings. i update the thread when i've had time to make changes. this weekend the SW chip should go in and i'll get the car out on the road for a sound check. still trying to find a means to make a quality sound clip - a phone vid just doesn't cut it. from start up and idle, i think i'm going to get the sound i was looking for.

http://forums.pelicanparts.com/porsche-911-technical-forum/817940-m-k-motorsport-muffler-arrived-today-not-your-ordinary-1-1-out.html

as far as brian goes, if i'm happy with a company's product and customer service, i like to spread the 'good' word. i've been self-employed since i was 22 y/o and i know the value of good PR and referrals. good companies and owners should be promoted and the opposite should be exposed - imo. for the record, i paid full price for my muffler - so no ulterior motives on my part.

I just used my cell phone - samsung galaxy II. I agree with your assessment.

I think the raspy sound was due to the recording - the bass sound may have overwhelmed the phone because I may have had it too close for the leetle mic to handle - the sheer awesomeness of the sound is too much for the phone (hi & low's get clipped or cutoff because the phone mic can't handle the range of frequencies).

Hey Rich, I know your post well! Great post.
I'm already a M&K customer as well. I'm running their Pre Muffler and SW chip and have been very happy with it them and the set up in general. This was my intermediate step before going to an all out sport muffler on my 86.

I also agree that good co.'s should be promoted. Been happy with most vendors associated with our form just would like to get M&K to put these up on their website to sample...hint,hint.;)

If I read correctly you have a, "'motor-sport," version of the M&K 1in1 out correct?
This is not the stock M&K 1in1 out, it has been modified, (other than the tip@ 3") so it may not sound like steely's?

correct. when i emailed brian, i told him of other systems i had had in the past and what i currently had on my C4S and how much i liked that - 200 cells and Fister IIIs. since i wanted to stay with a 1/1 configuration, he told me they make a 'motorsport' version of the 1/1 that isn't listed on the site. i asked to have that version built and i convinced him to give me a 3" brushed tip. i think the tip looks awesome and i have received a lot of PMs and emails about it. brian already has an order for one, but we're working on measurements/adjustments that would need to be made for this to be production ready - you can see those comments in my thread. to answer your question, yes, i would assume (and hope) that my muffler would sound deeper and likely a bit louder than steely's. it is still quieter than my 993 with Fister IIIs, though. :D