I have a 2009 997.2 and want the exhaust note to sound better.
I am debating weather to do the Gundo hack or a Xpipe? Or should I do both?
Would both sound to loud? Anyone with either or both can you chime in?

 

I have same car with gundo only and love it. It s the exact sound a the Porsch PSE. No drone and quiet on highway trips. Deeper rougher sound in town. I would suggest the gundo first and if that doesn t do it for you then go further. I have no advise on further as I have felt no need.

 

I tried several variations of center and side mufflers. I initially tried a crossover with the stock non-PSE exhaust and found the difference to be quite subtle. I can't recommend this route unless you are only looking for a subtle change.

I also ran Fabspeed cans for a while with their x-pipe. Eventually I stumbled into a well-priced used PSE and ended up using the Sharkwerks crossover with that. I like the sound of that combo the best.

The bottom line of my point is: Assuming you won't be happy with a subtle change, try the Gundo first and see if that is enough. If it isn't, add the crossover but don't be surprised when you find it gets quite a bit louder when coupled with the Gundo or PSE.

And for what its worth: Having had a Gundo on my first 997, I'd argue that the Gundo does a reasonably good job of approximating the PSE sound but I wouldn't call them exactly the same. Their sound behaves differently as the car moves through the RPM range, particularly in the 3.5-4.2k range. The Gundo sounds a bit more raw to me, but to be honest many here like that better. I personally prefer the slightly more even sound of the PSE and the ability to set it to quiet mode when the time and place calls for it, but it is hard to find one that is affordable.

 

I have the same car also, I did the gundo and that helped allot but I wanted even more so then added the BIlly Boat center muffler delete X pipe and that made it just right.
I'd say gundo did the most so do that first.

Even with a cabriolet it's only noticeable when on the gas, just cruising it's barely noticeable and no drone at all.

Open windows or put the top down and it sounds awesome!!!

This is coming from an old man,lol

 

I am thinking about picking up the Billy Boat center muffler delete as well as it is quite a bit cheaper than the Sharkwerks and the design looks a bit better as well from the pictures. Are you pleased with the B&B pipes? Was install easy?

 

I went from stock 997.2S non pse to sharkwerks x pipe and fister exhaust. Got way louder, aggressive, and raw. Cold start ups will make you grin. Sound is way louder compared to the non pse which is extremely quiet IMO. Also no switch to keep it quiet, just have to go easier on throttle and shift up at somewhat lower rpms.

 

Do both!!!

I bought my C4S knowing it had the Sharkwerks X-Pipe. The car sounded GLORIOUS like no other 997.2 I had heard. Part of the reason I bought it on the spot.

Come to find out it has a Gundo Hack sounds better than any exhaust I have heard on a NA 911

 

good to see this debated - I've not seen a side by side using the hack and an x pipe. Based on the pipe routing, the x-pipe shouldn't add or retract very much in the sound department if you've already got the gundo hack

ymmv
gundo

 

Gundo, being that you are here can you answer if the Hack and the PSE are the exact same other than the on/off function? Thanks!!

 

I think I'm going to do the Gundo first and see if I'm satisfied, seems like the least expensive option. Then the Xpipe if its not to my liking. Does the Xpipe really add any HP?
Most companies claim that it does, and they have dynos to prove it. Im still a sceptic?

 

The BB cross over pipes fit great and I would buy again.

 

OP: It sounds like you are making the right call. As far as horsepower goes I've never been able to "feel" the difference with the x-pipe, crossover, or intake... but I never dynoed it either. If there are gains they must be very modest. It is important to note that in general whenever you reduce restriction in the exhaust, you lose low-end torque but you gain high-end horsepower. If you are frequently running to redline then theoretically lower restriction gives you a gain. If instead you tend to shift earlier (maybe in the 4-5k RPM range) then maybe not so much.

Just FYI: Quite a while ago some guy had a thread on how to fix a rattling PSE. He included photos including one of the interior. I grabbed a copy just for the heck of it in case I ever wanted to refer to it. So here it is! Note that this is the pre-fix photo with a notable split in the cross support.

Even slight changes can have significant effects on acoustics. This has been discussed in various threads where different folks use different diameter cross-pipes for their Gundo mods or Fister; even a half inch seemed to make a big difference. In the photo you can see that in the PSE muffler the third pipe is not a simple cross-over like the Gundo but gets it flow from inside the can itself before it goes through the "mesh" that the normal flow goes through... so it does had some chance to resonate in the muffler can. Granted that the sound still ends up being strikingly similar. I am only saying that there is a difference and I could easily hear it when I compared my 997.1 Gundo to a 997.1 PSE while I had that car. Now which sounds better opens itself up to a whole different argument. And as for bang-for-the-buck the Gundo and Fister's implementation of it win hands-down.

 

I did gundo first then I added high flow cats - love it

 

it seems i want the gundo mod and x pipes