buz3rd

Hi guys i know this topic has been around but i like to clarify some questions.

Below is the pic of the Porsche Sport Exhaust.

-appears to have 2 connecting pipes
1) between inlet,outlet
2)between the end of the box and the outlet pipe

Original

[media]http://hk.youtube.com/watch?v=q4l3EBD1sVA&feature=related[/media]










Next is Gundo's Sport Exhaust hack



- just a sngle connecting pipe between inlet and outlet

Works similar to partial bypass as some of the gas will bypass the muffler and return to the outlet which produce the higher noise.

however some bros who have done this have commented that the improved and louder sound is produced during harder acceleration and at higher revs.

I think this make sense as during startup, and low revs, the gas will still flow as uusal into the muffler box first.

Now looking at the picture, the angle of the connecting pipe i think affects the way the gas flows.

Notice that the pipe is at an angle. The part connected to the inlet is lower than the outlet
A)
Soundclip:[media]http://hk.youtube.com/watch?v=525WgBfvL9Y[/media]





Compare to another pic i found.. seems that the connecting pipe is rather levelled.

B)




Not sure the noise difference for this too

So my question is which angle constitute to a better noise at startup and low revs?

I personally think a 'Y' type pipe is best to split the gas and produce a more balanced partial bypass even at low revs,




Next is another hack i found





D) Similar to 'C' design but addiotion of bypass connecting pipes

Is this the loudest design?


http://hk.youtube.com/watch?v=PkEPZp...eature=related


cant find the soundclip for this one on 997s ..

Question is what is the purpose of the additional outlet pipe on the extreme left ? Does it create better noise at low revs/idle?

Also, the connecting pipe between this additional pipe is linked above the other connecting pipe?

I suppose this is to prevent any clash on the inflow and out flow?

Looking at the original PSE, i see that there seem to be also this additional outlet pipe.

So, which is the more accurate hack design?

A, B or C?


The original PSE has lots of burble compared to the exhaust hack as far as i hear from youtube sources.


How do we create this idle noise.

chapman6264

Hi Buz,

Your post is quite detailed - i was actually wondering what all the popping is all about in my 2006 997S upon cold startup....is this noise even remotely related to what you are talking about?

Randy (no dipstick!)

buz3rd

Hi champ, my post is about the PSE hack on stock 997s cans.

I am not sure if yours is stock or sport exhaust.?

I love the popping'/burble effect on cold start up but it all vanishes after abit in my stock exhaust after perhaps 30sec?



Its more consistent in the PSE.

This post is a summary of perhaps all the exhaust hack design i can find for the 997s stock cans till date.

however, i am pretty confused of its effects.

Perhaps i am just looking for the most accurate representation of the PSE so would someone please tell me.

I am assuming the PSE muffler box and stock box are apple and apple and are exacltly the same.

Looking at the true PSE, i can see the difference is that it has an additonal outlet which makes it a true dual exhaust rather than the single outlet pipe on stock cans with dummy dual pipes.

I wonder if this additional outlet pipe is responsible for the 'popping sound' so yes maybe its remotely what i am talking about haa