PTParks

Hate to point out the obvious but just because the crossover pipes form an "x" does not make them "X-pipes". Crossover pipes and X pipes are NOT the same and affect exhaust flow very differently. The X junction is congested on the Porsche setup and does not provide the accelerated exhaust flow like on an American muscle car. My setup is not loud at all and has a nice raspy sound at cold start that quickly settles down to a slightly louder than stock idle that has just enough throat to let you know it is not stock. On the road the noise is muted on the inside (no drone) and mimics the PSE for sound without the convoluted and expensive valve activation. WOT brings on a strong sounding exhaust that I would stack up against any $$$$ aftermarket system.

Andrew Ward

Sounds good on start up but very very good over 3000rpm

Spokane5150

I'd give up a few inch lbs. of torque to let the engine breath better on top. You drive you car above 2,500 rpm anyway. If you drive it spirited on the track or on the road you be over 3,000 rpm's 99% of the time. I have heard that the x-pipe reduces torque. Typically, it's the headers that affect torque the most.

PHX 911

Please reread post #9, my original post in this thread.
It clearly refers to replacing the center silencer on 997.2 cars.
In a later post, I provided a pic of the Tubi exhaust showing the pipes that eliminate the center silencer.
If you're referring to internal muffler construction, or perhaps adding an X pipe on a Corvette, perhaps could post a link or a pic or 2 that addresses whatever it is you're talking about or take issue with?
That pertains to my post?

911Steve

One last question thanks for your patience! Will the Gundo hack affect my warranty in any way?

PTParks

Your statement about replacing the center muffler is correct, however the second part where you state that, " I'm not aware of anyone hacking the side cans, too, but you could." What exactly do you think a Gundo Hack does but modify the side mufflers?

From your posts I'm still not convinced you know the difference between an crossover setup and an x-pipe.

On the Fabspeed website there is a picture of their x-pipe with the center junction. Your Tubi crossover pipes are not an x-pipe.

I am basing my opinion on the efficiency of an x-pipe on what Sharkwerks published in a detailed tuning guide based on their experiences with modifying the 997.2 and what works and what doesn't. This is available (free) on their website and is a very good guide. They do not recommend an x-pipe for the 997.2.

Fabspeed website: https://www.fabspeed.com/carrera_2009.html

What Sharkwerks says about x-pipes in ther tuning guide:

I'm not trying to poke you in the eye over this, but we need to make sure we are giving valid answers to questions posed by fellow owners.

TerpsRED

I was lucky enough to find a set of already modified "Gundo" cans from a 6spd forum member. I kept my stock cans in case I ever wanted to switch back. I've had the gundo cans on now for several months and still like them a lot. There is really only a noticeable difference on cold start and at wide open throttle. Other than that it is totally stock sounding. No drone or rattle in any way. I'm sure I'll end up selling my stock mufflers to someone soon so they can be modified. I can't see going back. Inspection in Maryland caught nothing, and the car throws no error codes at all. I'm very satisfied!

PHX 911

Here's what I've done to assist our fellow members relative to this discussion:
https://rennlist.com/forums/997-foru...ielations.html

You can rest easy now. I do appreciate your concern, though.

Spokane5150

Ask your dealer.

911Steve

I was going to do just that, I just did not want them to know I was getting this done just in case they said YES! It would. Then they would use this against me on a claim. But I did call them and my advisor said maybe on an aftermarket exhaust But not on the Gundo hack he said its just for sound.
Thanks for the advice now I feel better.

Steve

911Steve

Ok, I got the Gundo Hack done today by Chris Sterling at "Grand Auto Works" in Irvine Ca. Did a 2 inch wasn't sure what I wanted but Chris recommended the 2 inch. He said this is what most of his customers Are getting done. It was a big improvement over stock, as others have said the exhaust comes alive. No drone what so ever at freeway speeds, you instantly here the improvement when just going through gears even on slow driving. I have a cab and maybe I can hear more than the coupe would. On the drive home also put the top down, very exotic sounding over stock. BTW, Chris is a very nice stand up guy and was a pleasure to have him conduct the work. I highly recommend Chris to anyone wanted this done.

Steve

Andrew Ward

Yes Chris did mine earlier in the week and he is a pleasure to deal with.
He also does painted consoles and all other parts which I am doing next along with an ECU program.

911Steve

Thanks again Andrew for the info directing me to Chris Sterling for this work to be done. Keep us posted on the outcome of your new mods. Andrew just curious did you have the 2 inch done to your mufflers?

Mark Harris

997.2

Did the Gundo first and it didn't get me what I was looking for.

Next added the Sharkwerks X pipe, cross-over, or whatever it's called........

That got me where I wanted to be. It is not loud as sh*t. In fact my wife didn't even hear the difference unless I went Sport Plus and floored it.

If I did it again, I would start with the center muffler delete first. My gut says that it would be enough and you wouldn't have to mess with the Gundo on these .2 cars.

Andrew Ward

Yes I had the 2inch done sounds great.