Has anyone done the "Gundo Hack"

[badges2]

I was wondering if anyone has ever done the "Gundo Hack" to their exhaust and has some info. It seems fairly easy to do and I've read plenty of positive feedback on it. My question would be about possible problems with emissions testing. In Illinois we are tested farily often and my concern would be that this would make the car fail the test. Any input? Thanks!

I have a stock 2000 C2 and I'm only looking to deepen the exhaust sound.

Here is a link to an explanation of what it entails:

http://www.renntrack...Hack-GUNDO-HACK

Edited February 28, 2011 by badges2

[CaptnCrash]

I was wondering if anyone has ever done the "Gundo Hack" to their exhaust and has some info. It seems fairly easy to do and I've read plenty of positive feedback on it. My question would be about possible problems with emissions testing. In Illinois we are tested farily often and my concern would be that this would make the car fail the test. Any input? Thanks!

I have a stock 2000 C2 and I'm only looking to deepen the exhaust sound.

Here is a link to an explanation of what it entails:

http://www.renntrack...Hack-GUNDO-HACK

Anything *after* the cats will not effect emissions. Some states do have noise standards though and they may get you there.

Good luck!

--CC

[balefire]

I recently did the "Gundo" or the "PSE" or the "Fister" hack.

Gundo may have been one of the first do it on a 997, but Fister has been doing it on 993s and 996s for quite some time.

In fact, you can buy it from Darin Fister at his website. fisterdmotorsports.

Since you have a mk1 w/ a 3.4L muffler, you will need a Fister stage II bypass. DO NOT get a stage I or PSE like bypass for a 3.4L since it won't work.

for a stage II bypass from inlet to outlet pipe:

-1.75" diameter, 16G stainless steel w/ bend, anywhere from 2 to 6" radius.

-if you buy the pipe online prebent, you can get a U-pipe and divide it in half for each side

-if you want louder, increase the diameter to 2" or more.

-ideally TIG welding, but MIG welding is ok if you're shop knows how to MIG weld stainless

-don't let the bypass pipe intrude into the inlet or outlet

-plasma cutter may help cutting the inlet / outlet pipe

note: the diamter of the stage II hack is not the same as the diameter of the stage I hack which was 2.25".

other note: the hack will note affect emissions.

Edited February 28, 2011 by balefire

[valley996]

Had FISTER do mine and it sounds great plus did the powder coating. Best of all the price was low for a 996.

[kieselba3]

Does anyone know if modifying the exhaust this way increase or decrease power? I know that Porsche uses this same idea in their sport exhaust, but would they tell toy if it actually cause a power loss due to a decrease in back pressure?

[valley996]

Can't tell any difference on mine, but it sounds faster! Ha!

[balefire]

Does anyone know if modifying the exhaust this way increase or decrease power? I know that Porsche uses this same idea in their sport exhaust, but would they tell toy if it actually cause a power loss due to a decrease in back pressure?

the partial bypass is so small, the few that have dyno'd the PSE have not found any gain in hp or loss in torque.