I heard that you dont want a polished or smooth intake. it will mix up the air more if its rough. but you do want a smooth exhaust.

 

it would help to have the intake smooth bcause the air will flow smoothly and wont loose any speed....

 

i have always heard that when you near the intake valve to leave the surface finish a tiny bit rougher so that it swirls or creates turbulance or watever you wanna call it. of course i would think on a turbo application smoother is better because you just trying to get as much air in as possible, the boost will create the turbulance for atomization IMO.

 

actually ( and this comes from my dad an old school hard core drag racer for 20yrs.)... he has told me that on fuel injected motors that there is no need for intake air turbulance to mix (atomize) the fuel. the injectors do that already, and that thier isn't enough time ( especialy on a neon ) for wind turbulance to actually do anything. if u take apart a 420A and look at the amount of space between the injectors and the intake valves its about an 2 inches from injector tip to intake valve center. then whatever turbulance u had built will end once the compression stroke starts. i dont know, I just dont think that having a rough bore would be of any real use. i think it would just create more resistance and lower efficiency. another thing is like those damn wind tunnel blades that they sell. saying you'll gain like 10-15 hp. those are just a plain bold faced lie and the fool who invented those and continues to sell them under false pretensions EVEN AFTER THEY HAVE BEEN PROVEN NOT TO WORK should rot in hell for taking advantage of ppl. sorry sometimes i get pissed about **** like that.

 

i agree completely on everything you said except for the wind tunnel blades you speak of. i assume your talking about things like the tornado and stuff like that people always try to sell. only reason i would ever be on the fence about them is that my friend bought two of them for his crx... on his very next pass he ran a 16.3 instead of a 16.85. i dont mean to say it was completely up to the two things he bought but he ran consistantly faster after that.we also got the bright idea to make one from sheet metal and try it in my blazer and it felt like it had a reasonable more *** off the line when i launched... but again i dont support them or say that they are real reliable. that was just our little experimentation with them.

 

Snake oil