dgz924s

Anyone here ever attempt or do a TB and AFM polishing? I have thought about making the interiors of the 2 smooth as glass but have no clue if worth it or if any adverse results. Not refering to boring or the intake itself.

This is for the NA not 951.....TIA!

Campeck

If your going through all that trouble..(probably for jack squat as it's the door that restricts air), just get an MAF!!

dgz924s

Curious is all. Even though the flap is there the surface it flows over creates turbulence. One thing you dont want is turbulence. But from looking in them they are much rougher and porous and look like it could use smoothing on the walls.

inactiveuser92616

smooth as glass will create more restriction than a slighlty noduled surface. This is because a (mildly) turbulent flow is harder to seperate from a surface when the surface curves, as opposed to a laminar air flow (which would be encouraged by glassy smooth surface). When flows seperate, it creates a low pressure area which effectively sucks the air back upstream, slowing your flow.
That said, there might be some gain from making the surface smoothER, just leave some sanding marks. I doubt the gain would be noticable by itself; maybe if you did this for the entire intake tract you could get 0.5hp on a stock engine. I dont know if porsche did this already or not, but port matching would be smart if you are going to do polishing. (Matching the shape/size of the connecting flanges and gaskets, such as between the throttle body and intake manifold)

dgz924s

Interesting...profound but interesting. Can't polish the intake or port it-class rules. I am always looking for the fastest,coolest airflow I can achive thus the question. I didn't think there would be much if any gain. Thanks!

inactiveuser92616

yep! sounds like your time would be better spent at work, earning money to buy better race tires!

dgz924s

I don't work!! Nor do I earn money! I just race my car and spend time looking for activities to do and my dremel skills need honing...pardon the pun! I have all the race goodies purchased just need more power! CHEAP

Dilberto

I did it on my ill-fated NA rebuild. I first wire cloth sanded the AFM and TB seperately, bringing back the silver casting. Then, I applied 2000 grit paper to smoothen the surface almost like porcelain. Its definitely a hand-blackener if you dont wear gloves too...

Damian in NJ

We had a 968 guy get his throttle body widened, intake manifold extrude honed, and a new chip. He lost power.

Manning

Dal,

I thought you could port/gasket match and bore up to an inch or so into the runners by IT rules?

dgz924s

Michael

PCA... can't touch beyond the AFM. Thanks for the imput all!!