Modifiying the exhaust is no different than changing the mufflers. The dealer cannot void any other part of the warranty except the mufflers. Unless, you really look up deep into the bumper, you cannot even tell they are not stock. Of course, the sound is louder.

 

You used the wrong size pipe if your intent was to make it the true PSE sound,

 

hey 1999porsche911,
i really think that this mod (florindi's first external mod) does not come as close to the 996 pse mod to a true pse sound.
i was thinking about having some bypass pipes made, then thought it might be easier to just add the bypass between the inlet/outlet pipes, will this give me a much louder sound (ie like the fabspeed bypass pipes)
would there be any downsides of having both the pse mod and the bypass pipe between the inlet/outlet?
what do you think will be an ideal pipe size for a bypass between the inlet and outlet
thanks alot

 

here is a pic of what i am talking about (bypass b/w inlet and outlet)
i stole it from jrgordonsenior (hope he doesnt mind), on rennlist he said he did a 1.5 in pipe where the ruler is.

 

Minimum size pipe would be the same as the other pipes. You should, however, go larger so that the pipe is on the OUTSIDE of the nipple and welded. Smaller pipe will reduce loudness as some have preferred. If you want loud, but not quite as loud a bypass pipes, use the bypass pipes with a restricter.

Playing with it might someday produce something like this:

http://youtube.com/watch?v=el2haZ-lkHI

Either way, you are losing lowend power in the NA engines.

 

by nipple, i think you are talking about the original pse mod, like the one the 996 guys are doing. or do you mean the new hole that is created in the pipe (by "nipple")
I have already done that mod, and dont think it added much sound.
I want to do this other mod (the one in my last pic) to get louder (like bypass pipes).
would both mods individually result in lowend power loss? and would they be even worse together?

 

I didn't use the wrong size pipe. It is the same size as the 997 PSE secondary pipe. The external mod is not enough and no larger size pipe is going to make that much of difference. This is because the internals of a 997 muffler is different than a 996. I don't have pictures to post of the internals and please don't bother showing the factory picture floating around of the cutout. This picture does not show enough detail of what is really going on inside the can. Like I have stated. The system is not as loud as a real PSE and that's what I wanted. But, it is substantially louder than stock. If you only do the external mod, then it is barely noticeable.

 

i completely agree with this comment.
but i wonder how the external mod i suggested would have compare to your internal changes...

 

I have heard the clips of that style mod on the internet. If seems as if it sounds more raspier by doing the mod you have described above. This is only an opinion and based on hearing a soundclip. The internal mods are pretty easy to do. The hardest part is plasma cutting the side. My weld job looks bad because I didn't have the right thickness wire for the mig.

 

I have not cut open the 997 muffler, but the 996 mufflers are EXACTLY the same internally whether you get factory PSE or not. I find it hard to believe, or see any benefit that Porsche would change that fact for the 997.

 

1999, what exactly did you do to get the sound in your clip?

 

Top secret prototype. I would have to kill you if I said anything. Retired Ferrari engineers can do amazing things.

 

why dont you celebrate your 1000th post by revealing the secret,
just kidding, i think the bypass pipes are the best choice for me.
do you think if i change the headers i will get any difference in sound?

 

Well, I have and it is definitely different. The stock 996 exhaust cutout is shown on Fabspeed website. Also, the mufflers are fabricated my different manufacturers. The stock is made my Gillet and the PSE is Eisemenn.

 

I got the same mod done with a 51mm. pipe to connect the bypass pipe to the outlet. The sound at idle is a little louder (at start up it is obvious) but from 2000 rpms it is definitely there and I like it very much so far. It is not too loud or too quiet.