ScottArizona

So my car came with stock headers, stock side mufflers, and a sharkwerks bypass. Car sounded really, really good, but I was intrigued by the prospect of losing a bit more weight and getting a little more sound in the lower rpm range (where the car sounds pretty tame before the exahust bypass valves open up) I had previously unplugged the valves, but with the center bypass, there was an obvious drop in low end grunt which I couldn't deal with, so I plugged them back in.

I was reluctant to switch to a side muffler delete seat up, but heard from a number of members that if I combine the side delete pipes with the stock center, the reduction in torque/power in the lower rpm band, if any, would not be noticeable.

So after sourcing a set of used pipes (straight elbows with the block off plates...thanks to USCTrojan for a great deal!), this weekend I borrowed my buddy's 997.2 center section that has been sitting on his shelf, removed the sharky, removed the HEAVY side mufflers, capped and tied up the left over vacuum lines, and buttoned everythng back up. I also swapped out the spark plugs and coils (there were some tiny cracks, so I figured why not), and dropped in a bmc filter.

(side note: One thing I found VERY interesting is that one of my exhaust valves was basically "stuck" in a half open/half closed position. It took a lot of force to move it with my fingers, and is still not moving freely). I don't know how long it has been like that, and its clear the other side was working because hitting the sport button did have an effect on sound, but it was also clear that I was losing out on the benefit of the closed valve at lower rpm, and the fully opened valve at high rpm! Moral of the story: check those suckers as you may be able to restore some lost power by servicing them)

Anyway, so I start the car up and its a good bit louder than my old set-up, even with the sport bottom on. It is immediately clear that this mod is NOT the equivalent of unplugging the valves becaues this sounds very different. Not obnoxious loud by any means (not as loud as the gmg "mufflers" I had on my old 996 gt3), but a good bit louder than my old set up. Sounds much deeper, and yes, a bit "boomier." I was liking what I was hearing as this is not a daily driver and I don't need it quiet in my neighborhoood as everyone is pretty chill. Fingers crossed that the sound/power was to my liking once I drove off and got on it.

Well, I can honestly say I feel no loss of power at all, and even feel like I have picked up a bit, although how much of that could be attributed to the fact that I had a faulty valve, I don't know. The engine definitely seems to rev quicker and the engine/throttle response is definitely a bit snappier. Whereas the sound in first and second below 3k rpm used to be a bit high pitched, it is now deep and menacing from 1k rpm to redline in every gear, with no annoying volume changes! As others have reported, there is some drone between 2.4-2.9 rpm, but I don't find it bad, and its not as bad as a number of exhausts I've had on prior porsches. And, I simply don't find myself in that range very much as I like to cruise at right around 3k, and at that rpm the drone is very minimal.

All in all I am very, very happy. I will not go back to my old set up. The car sounds mean, pulls better than before, and losing 40 pounds and the heat associated with the rear mufflers is just awesome. For any of you on the fence, I say go for it. If you are sensitive to drone, then I continue to recommend the sharkwerks bypass, as I have no complaints and would not have changed but for the fact that I wanted to lose a bit more weight and realize a bit more volume in the lower rpm range!

I'll try to get a few gopro clips up in the next week. (Anyone want to buy a good condition center bypass with black tips?

Fisher

Great to hear you like it!

Your comments about the minimal drone from 3K up, has my attention.

If I may ask about sound levels on a scale of 1 to 10. (Hopefully, your stuck valve will not complicate matters)

2 being stock with the sport button off.
3 with the sport button on.
5 or so with the sharky bypass and sport button on.

What would you consider the sound level to be, as you have it, with only the side muffler bypass?

Thanks

usctrojanGT3

Glad that you enjoy the side delete pipes since they were just sitting around my garage and collecting dust. Hope to see you out at Chuckwalla in the fall.

Spyerx

Same deal on mine. Mild drone from about 2800-3100 rpm. 72mph in 6th, no drone.

Center bypass is louder at full tilt than side delete.

Overall I like the sound and 'cleanness' of the side delete installation (no sides) better than center delete. Louder at lower rpm, has a deeper growl, and sounds sweet at full throttle.

Grizfish I'm in socal if you want to meet up sometime you can hear mine.

Fisher

Great! Looking forward to the clean sound, Spyerx.

guyc

I had these on and burned out center muffler after about 4 open track days--my guess is they are ok on street but if you track car the center muffler will eventually fail. Too bad because it makes the car sound incredible especially at idle and you drop close to 50 lbs. Guess too much heat running through too short a pipe into only one pipe on the center exhaust.

Spyerx

.2 RS ? Steel or titanium?

They can/will eventually blow a hole in them. Most just weld a plate on bottom where they tend to fail.

RedRSA

Wow; unexpected perception of the sound level, thanks Scott. Doesn't seem logical to be louder than Sport mode, but I haven't seen how the flaps actually work and if they are shutting the side mufflers off completely (which I assumed they were). If so, I don't understand how the sound level of the side bypass is much different than in Sport mode. Perhaps someone more knowledgable of the side flow will chime in. As for being louder than the center bypass in Sport mode I don't see how that is possible if the sides are completely bypassed in Sport, because that would effectively be straight pipes (+ cats).

Sorry to hear that because I plan to go with the side bypass! What was the failure pattern/what failed and where?

Does this happen more on the RS titanium center or GT3 steel center? Preventive or after the fact? Is there a common failure point that can be addressed? I wonder what is different in the Cup center to make it more durable?

woshimihei

congratulations you like

Just wondering how does this compare to the Sharky Track exhaust

RobT 394

I can only speak for my own experience. .2 center in titanium failed very quickly, as in a handful of track days. Went to M&M and cracked that after about 2 years of tracking so it did well. You can also get the cup center which should hold up well. If you track, they all crack eventually. Still the best setup IMHO for the reduced weight and improved heat management.

Spyerx

Titanium center is known to happen faster. Cup center steel is supposedly the same with 2 differences (I've seen them both side by side and it even has markings where the street part is drilled). 1. The rear tips are attached on cup, 2. the cup doesn't have the cutouts for the 2nd side pipes.

But eventually they all have issues, the florida guys had a thread that showed welding some 1/8" plate (I think) to the bottom of the muffler.

Not sure I'd do preventative, you'll know if it happens and it's an easy fix, not a big deal (unless titanium!)

RedRSA

Thank you. Makes sense to wait and see. Why is it every thing I want to do for an improvement in one area creates problems in other areas? I guess that is why some people just leave things alone; I however, tend not to be one of those! ;-)

guyc

i have a .1 gt3--the muffler still worked but it has terrible ripped sound in about 3 spots---lower 1k area so every time u take off, again in mid 2s and then again in low 3s--the range of each area was up to 500 rpms so it renders car undrivable.Very curious as to the fix, is it an external weld that cures it?

Spyerx

usually external, unless the internal baffles fell apart...

Tom@TPC Racing

+1.