thanks. I can't wait. I will also take pics and hopefully Vids of the deal.

 

Dropped it off yesterday. Should be in progress!

 

Wow, Well, if you are in the /Plano/Frisco, 121 and Preston rd area I would love to hear it...

 

Got the hack done with the 2" pipe. Deeper tone especially in the lower revs. Adds a harmonic from 3-4.5K. Louder at the top but not much different in tone. Glad that it is not that noticeable at normal cruising speeds.

Pretty loud, though with the 2" pipe. Don't know if I can also do the high flow cats without it getting obnoxious. Still not the tone I was going for, but definitely an improvement. Thinking about adding the x51 headers. You guys think that will make much difference?

Posted a video to YouTube with before and after.

http://www.youtube.com/watch?v=l1_O76t_ZI8

 

I live in dallas and 'm interested in the Gundo Hack for my 07 997S. From your video, it sounds fantastic. What type of pipe did he use for the hack? A T304 or better? My main concern is oxidation and it rusting. Have you had any issues with it so far?

 

I'm not sure what grade of stainless steel my mechanic used.

I looked at it the other day when I was showing someone- you can see the bypass right under the back bumper. The welding looked high quality with a nice even bead. No corrosion so far.

As I understand it you use stainless steel for the welding wire and blow an inert gas over the welding area as you work to keep out the oxygen. So, if the person doing the welding knows how to weld stainless steel properly it should hold up fine.

I'm on vacation now but if you like I can post some photos of the welds next week when I get back.

To me the bigger question is what diameter pipe to use. I used 2 inch pipe and it can be a little loud especially after I changed to the high flow air intake. I have seen other posts that said 1.5 inch pipe was not loud enough. Maybe 1.75 inch is the sweet spot but this depends on individual preference.

If you are interested I could record some better audio and send it to you.

 

Pictures of the welding job would be great. Based off of your video, I think the 2 inch pipe is the way to go. Its much deeper and throatier than stock, but not obnoxious.

I think I'm going to reach out to your guy in lewisville and hopefully get it done next week. I guess in the end, if it starts to corrode any, it gives me the reason to get the tubi or fabspeed!!

 

Next time I go to dallas I would really do all this mods.

I am also worried about rusting? I have seen improper and proper welding and it would really eat pipes.

The sound seems perfect, especially in the cabin.

Hey Doc, do you know if it void Porsche warranty?

 

I spoke to Steve at fifth gear in lewisville ( Ricky wasn't available ) and I was quoted a price of 450. Anyone wiling to share the price fifth gear charged? I mentioned several folks on this forum were stating 300, but he still wouldn't budge. However, he did say if someone got a cheaper price with them, they'd be willing to match..

Here's hoping to save 150 bucks

 

They charged me $200 for the pipe and $200 for the labor.

I'm sure the pipe didn't cost $200 but $400 total cost seems reasonable considering they have to take off the bumper, remove both mufflers, cut, weld, and reassemble.

You could get any muffler shop to do it cheaper if you removed the mufflers and brought them in but to me that was $400 well spent.

Sorry I could only save you $50 ;-)

 

Had the bypass done this morning. Wow, I'm thoroughly impressed. This is how it should sound from the factory.

I used Kens muffler shop in Dallas. Was referred to there by the service manager at parkplace Porsche.

 

The modification shown in post #10 appears to be a piece of aluminized carbon steel tube welded to the muffler tubes. It makes for a really bad galvanic couple. Both the aluminum coating and iron in the carbon steel tube will be sacrificial to the 304.

 

Sorry the pic is a little blurry. The weld seems to be holding up just fine.

 

That's great the welds are holding up. However, keep an eye on the welds IF the the tubing and welds are not stainless. My partiail bypass was done with 1.75" stainless tubing and weld, mendral bent and fitted as close to the can as possible and nearly vertical as fitted in final position when installed. The pipe length per side is approx 7.5" due to the bends/cuts (but I've seen hacks using straight 3" - 4" length tubing and they sound great too). My exhast was then media blasted to finish up the mod. At 3150 RPM there is a note change at near or WOT. There is no drone (gundo hacks do not drone) and there is a slight improvment in throttle response. As far as HP increase - none as far as I'm concerned but no HP increase was expected. This is strictly an audible note change. I would not consider my exhaust pitch to be low but there is a medium to high note change at near or WOT. And that is what I was looking for. $300 is what the mod should cost though I wouldn't expect a basic muffler shop to media blast the cans as a finishing step - not really needed.

 

Lookin for someone in Dallas to do this for a reasonable price. 5th gear says $675???? And $488 at RAC. It cannot be that difficult. Anyone have a suggestion around Dallas?