Gents...this is not the place to be selling anything...that belongs in the marketplace...this thread has good info so I don't want to remove or close it so please knock off the buying and selling

 

This mod has one problem....you can`t by pass the the 2 cat`s on each side....

one 100zell cat or 200cell on each side and you should be more happy...imho

 

How does this procedure differ from the PBK exhaust?

 

I agree with chuck...not a thread for advertisements....I am the J of the three letter acronym, TWJ mod,...one of the three original idea pushers...

The idea was to give people a cheap option to get more power and better sound.. I loved mine and it was great. Not perfect, but for the price...pretty amazing stuff.

I am sure the PBK option is nice, as are the other 25 solutions out there....just not here please. I don't want this thread closed down. Just take the stuff to PMland.

(It is cool have such a high number of readers....rare to get power for cheap and sound....we dynoed, etc. (whoosh did it..))

Jeff

 

I did the TJW mod and it was way better then stock! I used a 1 7/8" hole saw to max out what could be cut out to max out the sound.

After a while I got tired of the sound an honestly it started to sound like it was under water, just a weired sound to me.

I don't have to worry about smog so last week I took the OEM muffler off and reworked it myself. I used a 54mm hole saw to cut through the 1st 300 Cel cat. I took out a little more then that but that gave me the blue print. I also used a few other drill bits as this cat goes deep into the muffler.

When the drilling was done I stuck a shop vac in and sucked out the stuff, then stuck a high pressure air hose in the 1st 02 sensor hole and turned it on while using the vac, and last I use a magnet. I also used a spark plug fouler to get the 02 sensor out of the cat body and the new amount of air flow.

I painted it all black w/ high temp paint, polished the brass hangers, and the tips before putting it back on. The sound is Awesome!! and the drone is gone. It is a nice sound at idle and gets louder and more exoctic as you use the throttle. If you don't have an agressive smog check and don't want to spend any $ then take a weeknd and do this mod. If you have any questions let me know.

I would say doing the TJW mod w/ this cat delete is a must DIY if your smog will allow.

 

any pics or sound files?

 

Richard, I am interested in this and would like to see and hear your car. I'm in Camarillo just over the hill. What do you think?

 

So I had this modification done today. I went with a 1" hole on both sides. I really like the sound improvement. Sounds deeper and lower RPM's. Sounds best with the drivers window down for sure. A little more droan than stock at cruising RPM's such as 2400-2700. At 3000 is pretty much goes away. Can't tell if there is any power improvement but that comes tomorrow with the EPL flash. Also had EVO billet diverters installed today with fresh spark plugs. Thanks for getting me started Saving for a Europipe next.

 

Hello Ken, so you don't touch the baffles etc in the silencers you just remove the 400 cell secondary cats ? this is I know is a major job it cost me $1000 alone.

 

I'll add, this is a big job. I had a full afternoon into mine and it's not nearly as clean as Ken's. I put 100 cell in mine a couple of weeks ago. With stock tune, the 100cells were not 'enough' to burn off the exhaust smell. With the EPL tune, the car burns cleaner than it was with the 4 stock cats.

 

yes I have 100 cell cats in mine too (front) the whole affair took 10 hours of a specialist engineer

 

So Ken you also cut out/off the cap immediately behind the 400 cell cats (which looks like a pacman) in the attached pic ? are there no benefits to reducing the length of either of the pipes facing into the center section ? i.e cutting one or both flush with the 2nd section joint ??

 

So Ken you also cut out the cap immediately behind the 400 cell cats (which looks like a pacman) in the attached pic ? are there no benefits to reducing the length of either of the pipes facing into the center section ? i.e cutting one or both flush with the 2nd section joint ?? Or at least cutting the outlet pipe in the baffles section to the same length as the inlet pipe ?? What differs with the 996 GT2 here

 

Did this mod few weeks ago and got better power in lower end.

I actually got 1.1 Bar in 1st, with motor completely stock!!! (Did just change the MAF and plugs though).

Not completely satisfied with the sound, and this will speed up my search for exhaust...but it will suffice for now, and do LOVE the small extra power in first few gears.

 

Would have to agree Ken. I didn't see anything on the boost side of things after cutting the 1" holes. Still ran at stock .7 bar with an occasional .8. Now with the EPL flash it's 1.0.