I'm just going to go with a manual adjustment, however the valves do have the capability to be programed to be rpm specific, or by vacuum pressure. A'Pexi makes a whole module that you can tune that would probably give you the low end torque.

I'll keep everyone updated, I'm trying to keep it as simple as possible so that other people with the same pain can emulate what I did. I love them but sometimes I just need to simmer them down a little.

 

I placed my order, custom electronic valves which will slip over the existing pipe and clamp under the bypass pipe (via adapters welded). It was $370 shipped for everything including the valves, electronics, and adapters to make this work. A little pricey but it should bolt right on, I will update with pics when I get them in. Also if they are that simple and sucessful I'll share the guy who is doing these if anyone is interested. Still interested to see this other system that p0rsch3 keeps teasing about!

To keep this in perspective, I will basically have paid $500 with the bypass pipes.

 

I was invited by Kurt (p0rsch3) to San Pedro for testing out a brand new exhaust syst. for 996. Dyno and test run on local street.

It was pleasure to meet Kurt, Chris and Brian. Thanks for allowing Pcars experienced first hand. Wishing you and your product great success.

The sound of this new exhaust is awesome. You have to hear it.

http://videos.pcars.us/video/a7160a24-df33-4a6f-a4f3-9ab4015097ed.htm

 

Peter- Hey buddy, great meeting you and Carlos (CJBoxster) today. Thanks for coming out and lending support, and for shooting some vid. We really appreciated your help and input. Good times all around!

The vid you posted is great! We definitely need to reshoot with a better mic though, it sounds 3x as good in person IMO. My buddy Chris brought his pro cam with a boom mic but the #$@ battery was fried.


Here are the dyno charts from today. We did three pulls with the stock mufflers and then three pulls with the AfterHours Sport Mufflers. Surprisingly all three runs w/ stock mufflers and all three runs with Sport mufflers were very dead-on similar with results of each run. My car is a 2002 C2 Tip, the only engine mod is a KN Intake.

Net result is increased HP / TQ across the band, particularly in the 4-6k RPM range on HP.
The Afterhours Sport Mufflers weigh in at 8.25lbs each! The stock 996 mufflers weigh in at 22lbs each. So in addition to awesome sound and increased performance numbers there is a significant weight savings!






Here is a shot of the mufflers- They are 100% stainless everything, hand made, and use existing stock or aftermarket 996 tips.
Main perks are bypass-pipe-like ripping sound at WOT with a bit more tuned edge, reasonably quiet ride inside cabin, no added cabin vibration, and no brappy decelleration noise.
Cruising at 3-5k rpm at light throttle, you'd think you had stockers on. Open it up and set off car alarms



They should be ready for order in 3-4 weeks. Am working on an introductory price deal for 1st 7 or more interested 6speeders / pcars members. If interested shoot me a PM and I will keep those who are interested updated.

 

I'm running muffler bypasses now which I love but drives the wife CRAZY. Have you tested these with one can on each side? Maybe might be a compromise between bypasses and regular mufflers.

 

Yeah those look like a nice compromise, I get my exhaust control valves in today so I will play with those. I'll update once I get them installed but probably won't have time this week.

 

This exhaust syst. is design for guys who want more aggressive sound than aftermarket brands but not so loud like by-pass pipes. Also, there are guys who want to install by-pass but don't like the idea of losing low end torque.

This syst. is perfect compromising of both. In my video you can see the car was dyno test with left/right exhaust installed and the street test too.

 

JMHO after having used straight pipes, this is the exact compromise between mufflers and bypass pipes- because it is just a straight pipe with chambers that dampen the sound at cruise / idle, and reduce noise inside the car. So you lose 25% of volume at WOT compared to straight pipes but you pick up the "liveability" and performance charactersitics of a sport muffler.

If you went with one can per side you would get a lot more noise inside the car and go back to losing TQ. I don't think there would be any appreciable benefit over plain straight pipes.

 

Definitely can't wait to see pics / video of this- you'd better represent and post some good stuff or I feel a HUGE ban coming on...

Good luck hope it turns out good!

 

Well I got the exhaust control valves in today. The look very nice, great quality, etc. I hooked them up to my battery and tested the speed and control out. I'm very impressed with the operation of these. Anyways, one small problem, the adapter pipes are too large for the stock pipes coming from the cats. So I need to see what I can do about that. I don't know, I might throw the heavy *** cans back on for now. I'll update, here are some pics:

 

thanks for pics- I think you have to work on that camera focus and lighting... lol

You need an adapter pipe on the cat side that is 2 and 1/4" in diameter, perhaps a local muffler shop can weld up a replacement piece for that end with the correct pipe size.
Do you have any pics of the assembled muffler with the cutout attached?

 

Hahah yeah my camera phone at sun down isn't the best. No shot of the full assembly yet, I need to bolt them up first and play with the range the valves open, well really "close" to. I don't ever want them all the way closed, but I need to find the sweet spot for quite time. I'm kind of 50/50 on this project, I will need to probably cut a little off the bypass pipe for it to fit nice. I have to see if the effort is worth it. I know it's not a big deal, guess I will see. The project does seem to be fun, and I know when it's done it will be really cool.