I was reading somewhere a couple of months ago (i have used search to try find it) about grinding out a restrictive part of the exhause on the pipe that joins to the back side of the cats. I was wondering if anyone has done this, if it makes any difference, or on the weekend im going to hoist it up and see that someone was just pissing in my pocket and tellin me it was raining.:LOL: Any info is greatly appreciaed. thanks :zlove:
its called a pre-cat.. the OEM dump pipe of the turbo models has a catalitic converter inside it. apparently though these were only in the american version.. jap ones dont have it so yeah.. you would be wasting your time
wrong wrong wrong >> At the base of the oem dump pipes is a restrictor that can be grounded out. There's another restrictor which I think is in the cat section of the exhaust which can also be ground out. I believe this will make a feelable difference - I couldn't tell as I also upgraded turbos at the same time. Pre-cats in the dump pipes were put on US cars to meet the strict Californian emission laws.
Re: wrong wrong wrong >> Chewy is right, The first flange that you can see welded onto the factory cats does not have a 2inch hole in it it has a 1 1/2 or 1 3/4 hole (cant remember which) The cats themselves from memory have a 2 1/2 inch entry but because of this lousey bit of engineering are essentially restricted down a lot smaller. I imagine you will feel a difference if you ground the inner flange away. Its a lot smaller than the pipe diameter. Its only a bit of time so I would do it if you have the inclination. All the pipes then fit back up exactly the same as they did before.
Re: wrong wrong wrong >> wtf?? news to me.. haha ive got new dumps on there way and a new exhaust following.. why would they do that?? keep power at 280ps??
in the H pipe.. Just behind the cats, is a restrictor that brings the flow down to about 1 3/4, I used a hole saw that was a neat fit in the pipe to cut mine out, I beleive it made a noticable differnce to my stocky TT,
If i have an aftermarket 2.5" exhaust but with stock cats and no h-pipe would the restrictors still be there?
Maximum kW allowable in Japan on any production car is 208kW at the flywheel. That's why the restrictors are there.
yeh i had it done to mine wykked offered to do it for me, and he did a great job. from memory i even think he putty'd up the cracks in my exhaust for me too. afterwards you do feel a power difference :thumbsup:
Yours was nice and easy........>> Because whoever complied it had replaced the nuts and bolts on the cat flanges with new ones. Made it nice and easy to undo and the die-grinder made short work of restrictors.
Frequently wrong, offensive even, however in mitigation >>> >>> Andrew did email me today to correctly point out bad links in Tech A-Z :thumbsup: Perhaps an apology on forum, here or there, might be forthcoming to engender future goodwill between all.
Aren't you On first name terms with them all, never seemed to be any shortage of them to point out yours.:LOL: Where have they all gone?
Re: We NEED someone to point-out other peoples shortcomings. I thought this why god invented mother in laws !! :LOL:
Re: Don't be so hard on Miniman, Shane. He's frequently wrong easy on love.. pretty sure that was the only time i was wrong.. besides.. i was semi right and not fully informed whos deleting my posts anyway?
