I've tried normal dremel stones and a carbide bit but neither can hardly mark the exhaust diffuser welded into my S4 NA's exhaust port, but I need to grind them down a little for my port job. Anyone have a suggestion as far as what to do? I don't want to remove the sleeves completely . . anyone got any TII sleeves from junked housings you could sell? How about a diamond tipped dremel bit, would that work?



I know that Judge Ito has ported NA exhaust ports . . but he is seldom present here anymore.

what do those things even do and why don't turbos have them? what would happen if you just took them out?

i grinded mine out with a straight tip carbide bit for a dremel. took a little time but worked fine. i completely removed mine. turbo sleeves would probably be easier if you have them available to you. i think they are on there because it quiets down noise.

I don't think it hurts anything to remove them. My friend took them out on his bridged 13brew with a t-70 and had no problems. I have removed them on my 12a peripheral project.

Youre thinking of the wrong. All rotaries have exhaust sleeves, which is what you are talkign about. N/a's have a diffuser in the sleeve to reduce noise. Thats whay he was talking about.

so umm i forgot to ask you where u got you rims done???

You asked on my thread about them, and I replied there. I did them myself, in my garage.

so what would happen if you took the hole sleave out???? and how do they come out?

haha i guess i never checked back, nice



you would need a sleeve in there to have your car operate correctly. you can remove them by tig'ing the roll pins on the side of the housings and pullin them out.

Yeah I just used a carbide drill bit on a drill press and it ate right through the roll pin with no problem. One of the sleeves took a little persuasion but the other came out fairly easily.

Why do you say that? My car runs great with them out. I posted pics in the porting practice thread a while ago. But its not for everyone. It moves the powerband up, and makes the car very loud. When I had a stock engine, my car was barely louder than stock. With the same exhaust, and those exhaust ports, my car is almost as loud at redline as my friends gxl was with a stock motor and NO mufflers. He had headers, and a straight pipe. You cant hear the person next to you at WOT.



Basically, if you wouldnt drive a BP, then keep the sleeves. Its loud, and the powerband is high.

You have to take the sleeve off and keep them off if you want to truely port the exhaust. The benefits of them is to have good heat transfer into the exhaust. With them is a restriction and not a true port job.

Ha! True port job!



I'm a wannabe engineer. I am building an engine for a compromise (dual duty) role: civilized exhaust volume but able to flow to match the street ported intake ports. If you mean true race car or full race car, forget it! This will be my daily driver and weekend autocrosser.



I got a pair of TII sleeves on the way thanks to a want ad on the evil forum. I'll smooth them out and open them up a tad, and open the exhaust port a couple mm lower than stock but that's it. I want a decent midrange.

huh i was always under the impression if you had no sleeves your housings would become too hot while driving... but if you run no sleeves, wouldn't you have to make a custom header to "port match" the exhaust port to the exhaust pipe?

I had to grind the hell out of my RB headers, and its still FAR from a nice transition. Im in the process of making some custom headers to alleviate this though.



I never have had a problem with heat, in 12K miles in the blistering coastal Georgia heat. But, I did ceramic coat the inside of the exhaust ports, and on the motor Im about to put together, Im ceramic coating the intake ports also.

my exhaust (before ceramic coating)

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