slicky rick

Exactly as the title states, has anybody actually tested a car with the gundo hack vs stock or one with PSE? Test meaning dyno. If the test says that the is no actual power loss then the gundo hack is really a good mod with PSE sound for so much less!

seapar

Not sure about gundo hack pre and post dyno but the Sharkwerks center muffler bypass (for 997.2) has pre and post dyno graphs on their website or you can search the threads. Also not an expensive mod and does increase exhaust sound above 4K a little bit.

Matt(inMA)

Have you actully looked at the Gundo hack? There's no way there can be any "power loss". It's nothing but a crossover pipe at the intake and exhaust of the muffler. It's a minor mod guys....

marcus0277

Anything that modifies the routing of gasses into or out of the engine can affect power (positively or negatively). The dynamics at play are a lot more complicated than most people realize.

Skibum

+1

PTParks

Maybe so, but from my personal experience with the hack is that any loss in power (or gain, if that's possible) is miniscule at best. Mine runs just as good as before, pulls great in all gears, gets the same gas mileage as before, and sounds like a Porsche should.

Matt(inMA)

Not true if kept in perspective. This mod will have zero effect on the performance of the engine. Zip, nada etc...

Matt

swajames

I agree - I have a Gundo on mine and it feels no different than it did pre modification other than it sounding much better.

Minok

The flow rate of gasses out would be limited by the most restrictive part of the exhaust system. If the restrictive part is part of the muffler not bypassed or the cat, or even the pipe back to the muffler itself, or the exhaust manifold, then bypassing the end muffler stage would not change anything other than acoustics.

Changes in exhaust that would affect performance have to be changes in pressure seen at the exhaust manifold by the engine. Is the gundo hack one that eliminates the most restrictive portion of the exhaust system's flow?

SAN997

It is an engineering fact that modification of the exhaust, even reducing back pressure, can possibly reduce HP. This is most apparent on 2-stroke engines, for example. It is possible that gundo could cause a slight reduction in HP.

Bullseye7

If Gundo hack reduces HP (which I haven't noticed at all). Couldn't the same be said about when PSE is on vs off then?

I doubt Porsche engineers would give PSE owners better sound at the expense of power. That would seem counterproductive to have the car sound more powerful but actually be less powerful.

bigfish1

+1 Porsche would not take a horsepower reduction to improve sound.