964 Exhaust: less is more.
#1
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I had been running primary and cat bypasses and ruminating about the elimination of the deadweight and restriction of the secondary, but as a future project with other things (big yellows etc.) on the go.
Then providence struck. The other day the secondary developed a pretty loud internal rattle that meant dealing right away with the nasty thing. Off it came and I had G pipe to put in its place. Have you heard a the 964 with cat, primary and secondary bypasses?? WHAT?! I'M SORRY YOU'LL HAVE TO SPEAK UP I CAN'T HEAR YOU!!
I like it loud but you could never drive on the street- not around Atl anyway.
Its full on Cup car loud.
So I went up to Kinetic and they fabbed a baffle inside the cat bypass (because unlike the G-pipe its nice and straight easily accessed). One baffle is nice but its still way too loud. The addition of second was hard to distinguish from just one- too loud. Hmm.
I did NOT want to put the secondary back. Unlike Oprah, having shed the 25 lbs or so, I did not want to put it back on. So I suggested putting the cat back on to see if that would tame the volume and voila!- loud, but not too loud IMO. Right on the limit. Nice and deep that at low revs is streetable. If you planned to rev it, you'd better look around first. I tried it on a hwy off ramp. Awesome.
This is not for everyone to be sure- but I don't drive much on the street and when I do I putter around. Its fine on the hwy and for track I'm just going to put the straight pipe (with baffles) back on.
Then providence struck. The other day the secondary developed a pretty loud internal rattle that meant dealing right away with the nasty thing. Off it came and I had G pipe to put in its place. Have you heard a the 964 with cat, primary and secondary bypasses?? WHAT?! I'M SORRY YOU'LL HAVE TO SPEAK UP I CAN'T HEAR YOU!!
I like it loud but you could never drive on the street- not around Atl anyway.
Its full on Cup car loud.
So I went up to Kinetic and they fabbed a baffle inside the cat bypass (because unlike the G-pipe its nice and straight easily accessed). One baffle is nice but its still way too loud. The addition of second was hard to distinguish from just one- too loud. Hmm.
I did NOT want to put the secondary back. Unlike Oprah, having shed the 25 lbs or so, I did not want to put it back on. So I suggested putting the cat back on to see if that would tame the volume and voila!- loud, but not too loud IMO. Right on the limit. Nice and deep that at low revs is streetable. If you planned to rev it, you'd better look around first. I tried it on a hwy off ramp. Awesome.
This is not for everyone to be sure- but I don't drive much on the street and when I do I putter around. Its fine on the hwy and for track I'm just going to put the straight pipe (with baffles) back on.
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#3
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I will post one next week from RA. But yes, its louder than primary and cat bypasses with Secondary still in place. Which makes me wonder if it is also is less restrictive.
The car gets dyno'd on Monday in this iteration (with MAF as well) but I'm not planning on swapping exhaust parts in and out so no meaningful conclusions can be drawn.
The car gets dyno'd on Monday in this iteration (with MAF as well) but I'm not planning on swapping exhaust parts in and out so no meaningful conclusions can be drawn.
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I'd love to see a dyno comparison with the stock cat back on vs off. Loudness aside, I'd be curious which of the three components if returned to stock would reduce power the most: stock cat, primary muffler, or secondary muffler. And does the car truly make the most power with all three bypassed.
I also own both the primary bypass and secondary bypass, but have not put the primary bypass on it for the same reasons you discovered (too loud). I'm currently running a cat bypass and secondary bypass.
I have a spare primary muffler and I plan to take it at some point to a muffler shop and have them modify it to be more free flow. Or just cut the inlet and outlet pipes off and weld them to a new freeflow muffler in between so it fits in the same space as the oem primary. The goal being more power while hopefully keeping the decibel level remotely livable.
I also own both the primary bypass and secondary bypass, but have not put the primary bypass on it for the same reasons you discovered (too loud). I'm currently running a cat bypass and secondary bypass.
I have a spare primary muffler and I plan to take it at some point to a muffler shop and have them modify it to be more free flow. Or just cut the inlet and outlet pipes off and weld them to a new freeflow muffler in between so it fits in the same space as the oem primary. The goal being more power while hopefully keeping the decibel level remotely livable.
#7
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The grey one here is the one I'm referring to- which did you nearly buy?
Nothing wrong with the car, ahem, in yer avatar!
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#9
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When i first got my car, i allso tried it with a straight threw pipe. LOUD is an understatement.
Had to shout at sumone stood right nxt to me for them to hear me.
Had to put the last box back in.
Did sound good thou
Had to shout at sumone stood right nxt to me for them to hear me.
Had to put the last box back in.
Did sound good thou
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#10
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I have been running a cat bypyass, primary bypass and the stock secondary. I recently put the cat back on and was mildly disappointed as the rumble went away. It was a great onramp thrill, especially while going between concrete walls/barriers.. I was hoofing it just to hear the sound.. awesome.
#12
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I hope it snows! Just kidding. Looking forward to the video. A few laps in succession would be nice. ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
I run a stock cat and no muffler on the SC. It sounds awesome but probably not ideal for power. I'd always heard that the cat is the most restrictive part of the exhaust system. I think Bill Verburg posted the flow rates for the 964 exhaust...it's around here somewhere.
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I run a stock cat and no muffler on the SC. It sounds awesome but probably not ideal for power. I'd always heard that the cat is the most restrictive part of the exhaust system. I think Bill Verburg posted the flow rates for the 964 exhaust...it's around here somewhere.
#13
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Tom's car inspired me big time on the grey car and I told him so and sent some photos. It was close but not the car in some meaningful ways.
As for the silver car- I got what I think was a great deal on it and it seems to run as well as the grey car (with less miles and top-end job). Its also dry as a bone since I bought it.
And as for snow I'm taking chains just in case ; ) No in car cam as yet so it'll be wife-shot exterior shots of me being lapped no doubt.
As for the silver car- I got what I think was a great deal on it and it seems to run as well as the grey car (with less miles and top-end job). Its also dry as a bone since I bought it.
And as for snow I'm taking chains just in case ; ) No in car cam as yet so it'll be wife-shot exterior shots of me being lapped no doubt.
#15
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