well, if biggers better, get one from a new Z06, its 90mm..lol...

but seriously, how do you determine when its Too much size?

 

when you start losing power

there is actually a formula to determine the theoretical "maximum" throttle body size for gains.. but i dont know it. and the one howell automotive lists, isnt exactly correct (somethin to do with the volumetric efficiency part of it)

just think, 1.8 liter hondas have 80+mm tb's available and have shown to make gains. the focus zetec motor has 70+mm tbs available. yet the largest neon tb available is 60mm?
makes ya wonder huh.
granted, a good bit of it is due to the ~52mm neck in the intake manifold making it near pointless to go much above 60mm.. but if you removed that neck (as i have) then whats stopping us from using a 70mm tb or larger?

 

hmm..interesting....

 

I'm looking at this place, I think is out of Pennsalvania, their website is http://extrudehone.com/ pretty appropriate lol. Actually my dad went out last night and when I came home he's like you might have a manifold coming in, way to spend my money lol (like I care). He bought it from the junkyard for $120, we got one from the junkyard because I can't be without my car because I have school, work and other things, so we bought another one. We are actually saving like $30 because my uncle cn blast it and everything so all we have to do is get it ported and polished and extrude hone.

My dad is quick to get performance..."When are you gonna have to money for this and that..." WHEN YOU WIN THE LOTTO lol

 

while it is optimal to get it hand ported and polished and then extrude honed.. youll notice little to no gains from the extrude hone if the port and polish was done correctly (like if nick riley at NRGYheads.com did it, or Eddie Fierro as the two best examples)
so, save some cash. just get the port and polish and skip out on the extrude hone.

 

Yeah I sent an e-mail to one of the guys and that's what they said...

Chad:

Thank you for your email. We can apply an S-Series non-wettable dry film coating through the inside of the intake manifold, which has shown to increase flow by about 3%, however after Extrude Honing it I don't know if it would make even that much difference, especially on a dry intake like the Neons (where only air flows through it). That 3% was gained on a carbureted engine. So I don't think it would be a good bang-for-the buck for this application.

 

?
that film hes talking about was completely seperate from what i was talking about :lol:

im sorta thinking you are confused when i talk about porting and polishing vs extrude honed..

aight. lemme describe the processes of each just in case:
extrude hones: a mild abrasive putty is forced through the intake manifold via air pressure. this carves out a path on its way out of the manifold, but does very little in terms of "porting". its mainly a very nice polish job.
port and polish: this is done by hand with the proper tools. the manifold halves are seperated, and extensive work is done to both halves. the ports are opened up more, and gasket matched. the "turtles" are reshaped. the tb neck is opened considerably, the injector humps are often removed to further help airflow..
after the porting part is done, the polishing takes place. while not as smooth as an extrude hone job.. its still quite sufficient to provide you with some nice gains.

as you can see, much much more is done during the port and polish job than the extrude hone job.

 

WOW lol, my bad wrong part, yeah what he's talking about is the film they put on after extrude hone, my bad lol

 

 

Nothing. I'm currently looking at a 66mm TB on my desk for my Neon.

New head and Tb hopefully go on this weekend.