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YOUR RESEARCHGundo hack/Fister D
Leading reported evidence
Replace mufflers at home
Performed · outcome unconfirmed
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Performed · outcome unconfirmed
(Thanks Dennis) I had Dennis' old mufflers modded at my local shop with the "gundo hack" mod, then swapped the mufflers at home.
Leading evidence: 'Replace mufflers at home' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check ", right' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Suggestion
Guys, just to confirm again, this does not affect the car's ability to pass a "Smog Check", right?
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Suggestion
they are different, check the photos in the second post to this thread.
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Suggestion
Could this potentially cause a fail at the clean air (emissions) testing?
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Rennlist: 1 discussions
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Can anyone provide photos showing left and right modifications. Considering doing this and want to be able to drop mufflers off at a local shop with photos to duplicate the modification.
Thanks, what is the sound difference between both? Hard to tell listening to many of the youtube videos. The first pic, you basically just cut a hole in the can? There is nothing behind that area (hollow space).
The top picture is the way the factory does it except they have a solenoid valve in line so you can turn it on or off but many people complain it is isnt loud enough. The bottom way seems to be the much preferred of doing it. I did it to mine and i love it. It is just about perfect.
So thinking of going Fister D mod (bypass pipe between inlet and outlet). Looks like a tight fit using a straight pipe due to what appears to be a bolt on the muffler in that first photo. I notice the actual Fister photo shows the bypass pipe with a bend in it but no bolt on the can.
Not ever having the mufflers off the car not sure what to expect. I am most likely going to try to have it done locally to save on time and shipping charges. Can anyone here address my concerns with the use of a straight pipe and tell me what diameter tube to use between both.
Mufflers serve no other purpose (to my knowledge) than to turn down the sound of an engine.... Thus there should be no effect on emissions other than noise emissions.
http://auto.howstuffworks.com/muffler.htm
I meant to say bolt from the clamp as I know it needs to be a good position to be able to reach it from under the car. so that if you want to remove the tailpipe piece you do not have to remove the muffler.
Anybody in the northeast, specifically metro NY area have the Fister D mod done at a local shop?
I'm with Mark in the fact that I'd rather get it done locally and not deal with the cost, hassle & down time involved in shipping mine out to the west coast.
Any recommendations are appreciated.
Mine is a 3.4 and i did the Gundo and i may go back and do the Fister at some point, as i think i need more.
HYPER911 is on the forum and he had both done if I recall.
As far as I know the Fister mod and the gundo hack are the same modification. The only difference is Fister is a company that you can send your cans to for the mod and the gundo hack are directions for a local muffler shop to do the work.
The original Fister and Gundo were the same, and they are the same as PSE without the PSE shutoff solenoid. That hack was quieter on 3.4 mufflers.
Fister started the short pipe in the second pic because customers wanted a bigger difference from stock. The short pipe hack is louder.
Mark,
I spend most of my time on the 997 Forum now, but I am glad I stopped by the 996 Forum tonight because I can help you out.
The "bolt" you referencingiing is actually the clamp that connects the pipe which has the exhatips onpson oppositeosit end to the muffler.
See my post from January 2008 (damn, it's been that long?) for a PET diagram of the 996 exhaust system and instructions how to remove them and a couple of pics which show the "clamp."
996 Exhaust
Hope this helps. PM me if you have any additional questions.
I did mine with a straight pipe. I used a 1 5/8 pipe. I wanted to use a 1 3/4, but it was too thick. I actually cut the factory pipe off as well and then welded them all in together. Love the sound..
Does the Gundo hack make it louder too ?
Porsche 997 Gundo hack 2 Exhaust bypass
Porsche 997 Gundo hack 2 Exhaust bypass - YouTube
I have the Porsche Sport Exhaust (PSE) and I like the sound of that.
Which is a better sound PSE or Gundo ?
Which is louder ?
Can you do a Gundo hack on a car with PSE already ?
Here is a before and after PSE install
997s Porsche Sport Exhaust - YouTube
The Gundo hack is for people that didn't have PSE or couldn't afford it. It makes a very similiar sound. The advantage of a true PSE system is that you can turn off the louder version at anytime. The Gundo or Fister mod is permanent and will always sound on the louder side.
Do NOT ruin your factory PSE. If you want it loud all the time, sell your factory PSE for $1k-gazillion dollars and spend ~$350 on the Fister and use the rest to fund another mod.
When I did mine, I bought a set of mufflers from another rennlist member and had them shipped directly to FD Motorsports. When they were completed and shipped to me, I did the installation and then sold my mufflers to another rennlist member. It worked very well!
I am that Rennlist member. (Thanks Dennis) I had Dennis' old mufflers modded at my local shop with the "gundo hack" mod, then swapped the mufflers at home.
Then I sold my old mufflers to Darrin at FD. And the circle of life continues.
Fister D. FD Motorsports is a great group to work with. Their quality and fabrication was exceptional. Worth every penny.
I cannot tell you how cool it sounds in person, or the number of compliments I get. Video and audio recordings don't do it justice.
A friend has PSE. I'd say the sound is very similar.
Guys, just to confirm again, this does not affect the car's ability to pass a "Smog Check", right? How does it impact the peppyness? More peppy I assume since it can breathe better?
You may want to check if this is an issue with CARB as part of their visible modifications rules. I don't know how hardcore they are or how closely they check.
As far as 'peppyness'. It depends on which mod you do - either the third port connected or the cross pipe between input/output pipes. The loudest mod is the cross pipe. At WFO it is really loud. Anything above 3 grand on the tach might be too much for a lot of people. Mine starts up with a 'bark' which is neat and keeping the revs down around my area and short shifting is key. On ramps or highway I could care less as well as at the track. Good thing is there is none of this 'drone' on the highway you get with some aftermarket cans.
There is a slight mid rev range loss in torque in my back of the pants device but seems a little freer above 5K. The third pipe mod seems better at low end from what my friend reports. Everything is a trade off.
The extra pipe mod that a friend has seems to add a nice 'burble' on over run and replicates the factory option with the valve. Its generally the more popular mod and less aggressive sounding. None of these mod's are for performance.
There is no benefit in getting both mod's as the guy who did mine says the owners who insisted on having both pipes installed later came back to see if he could reverse the mod and seal up the holes, (he couldn't). The report to him was that this mod loses torque on low end. His theory (he does a lot of race exhausts) is that the two mod's work against each other and cause flow issues affecting back pressure. He won't do both now - its one or the other.
Good info guys! From the video's I like the sound. It definitely doesn't sound like a Jap ricer which is nice. I like the "burble" so, probably I'll go with Gundo vs. Fister D especially considering that mine is a Cab and I'll probably never track it.
