Mzsaad

hi guys,
been itching to make my 997 sound more agressive.
anyone tried gundo hack? i have listened to a few on youtube but want to listen to the sound in person. i know gundo hack sound different than stock but is it also louder?
anyone want to make me listen to their silencer?
thanks.

docdrs

oh yes it is louder.....you will NOT be disappointed....do you have a .1 or .2?

Neb

I had this done last summer, it sounds a bit louder. If you want more sound think about removing the center muffler if you have a 997.2

Mzsaad

mine is .1.
the pic is of .1 or .2?

theiceman

that's some nice cutting and welding there.

docdrs

Pic is a .2 but someone already used my template for a .1 with success. Had a welding shop do the nice welds for $80, I did the rest

Torontoworker

This is actually called the 'Fister' hack if we want to use the correct lexicon.

The 'Gundo' hack is the hack that puts a bent pipe into the unused port on the cans that the PSE option uses with the little flap.

The Fister is LOUD - the Gundo is loud(ish).

I have the Fister. It is OPP... LOUD...:icon107

It also depends on the diameter of the pipe used - mine matches the input/output dia.

If you are on the fence about sound levels - go for the Gundo to replicate the factory option which of course you can't just flick a switch to turn down. But if you do the Fister hack - you are stuck with a sound level that may be too loud for you to live with. There are times when mine is too loud - espy WFO and you are between buildings downtown. The Fister starts up with a 'bark' and idles louder than normal and is loud at anything above 2500 - where as the Gundo comes alive a little louder and takes higher RPM to be really noticeable.

There is even a combo of the two hacks but is not recommended as it kills torque - something to do with the back pressure reduced.

theiceman

Gundo

Torontoworker

Exactly.

I don't know the history of the naming of these hacks but somewhere back in an old 996 thread the Gundo was named after the first guy to do this mod and post about it. The Fister came after and was named for the muffler shop in the US to do this hack (he does both). He is still in business today doing mail order although any half decent muffler shop today can do a reasonable job on either hack - its not Saturn V technology.

9964runner

the volume of both hacks is dependent on throttle position, so affected by driving style. As far as quiet<loud is all personal preference, although after a while most adjust and want a bit more.
I've had the Fister (pipe to pipe) for years recently added a 200 cell x-pipe and still wouldn't say it is to much for a DD. Ther are many around the GTA with this mod, I'm sure someone would be willing to take you for a spin to sample, I'd be game if you can wait a month or so.

Torontoworker

I have a sound level app on my phone and the Fister is definitely louder than the Gundo (cars and coffee testing!) as far as we wanted to test in a public area. I got pulled over by the OPP on the Weston Rd to 407 westbound ramp and had a little debate about 'the goddamn noise you're making'. Yes, (sigh) I didn't see the white 300 behind me and clue in to the fact that he was OPP... as I put the boots to it. Thank god I dumped my speed as soon as I see him roar up behind me. I was able to talk my way out of a ticket after convincing him it was factory, 'See, no modifications - both mufflers there officer'. Some how he bought it or was too lazy to argue and I got away with a warning to, 'keep it down'. I think he knew if I did have a mod I 'd just reverse it before court anyway and he had no sound measuring device - just his 'opinion'. He must have had a fight with his wife that day...

StanThePorscheFan

I have the Fister mod and love it.

AltVelo

What timing as I'm looking into this as well. Fister has a youtube video of their in comparison to stock. Anyone know what size diameter is their bypass? Based on their photo looks like 1.5 or 1.75? I read most go with a 2" bypass

http://fdmotorsports.net/category/fister-exhaust-997/

This is the first I read the Fister is loud but I'm not questioning that. It's easy to see why the PSE would be quieter(as in exhaust is still routed into the muffler). Based on feedback though, the Fister method has been positive for all size bypasses.

9964runner

Downside to exhaust upgrades is you have to be outside of the vehicle to get the full impact. Close call with the OPP. Our 400 on ramp by the cottage is very long and snakes through the local granite, I was accelerating rather enthusiastically in 3rd, as I round the bend OPP radar right there! though for sure I was busted, with a close eye on the rearview I decelerated to merge with traffic wondering how I got away with that one.

docdrs

I actually believe that is the Hanksville hack , Gundo is a straight inlet outlet hack. The Hanksville was done to mimic the pse which has the valve on this pipe. It is not as loud as the Gundo as it still passes through some internal baffling. Iirc

Here is the original as I can find Gundo post. This was before FD Motorsports started in 2009

http://www.6speedonline.com/forums/997/98396-pse-waste-money.html


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