On a stock 305 with typical free / low-buck mods including gutted air box & K&N's, air foil, and "modified" cat, would a 52mm throttle be too much? Would it kill torque / bottom end and help top end? Would it help all around? Would it be wiser to stay with stock 48mm? Comments? Thanks in advance!

From what I've heard before on this board, the stock 48mm is good for over 400hp. They even use it (a 48mm TB) on the RamJet motors. I don't think you would notice any improvement at all on a stock 305, yet, I personally think it would hurt your low end torque, and your wallet too.

Stick with the 48. If you really built the motor up maybe it could use it. They had a article in Hot Rod a few years back where they track tested stock 305s with bigger throttle bodies and they actually ran slower.

keep the stock throttle body it makes no diffrence what so ever in power to got to a 52mm. The only thing cool about the throttle body is the loud sucking sound both from your wallet and from under the hood.

On a 305 application, please clairfy this for me..I'm SURE people have made 5000 +h.p with 48mm throttle bodies. What puzzles me is this: we do all these little free / cheap mods ( port plenum, gut air boxes, forced cold air, K&N's, remove MAF screens & fins, air foil, etc ) for every molecule of air available. How can going from a 48mm with to a 52mm , which would make more air available, espeically at WOT, possibly make you go SLOWER? I could even understand a 58mm being to much , maybe too lean etc. Could someone explain this concept to me? Why supercharge or turbocharge , then? I have been led to believe MORE AIR is better, not just a little more. Comments?

I don't know about it really making you noticably slower but, it has to do with air valosity sp? bassically how fast air moves. and how it creates harmonic waves in you intake it is actually kinda hard to explain but, there is a post on porting fairly resent with a link that explains some of it.

try this link
http://grapeaperacing.com/GrapeApeRa...ntaketuned.cfm

Pauls, more air makes you go slower because in addition to having the air there, you need to introduce it to the combustion chamber at a certain velocity. The faster it rushes into there, the more effective it is. Getting the balance between volume and velocity is a delicate balance. Having too much throttle body is just like having too much cam. Think about it. The cam is opening and closing the intake and exhaust valves, which lets air in... just like the throttle body. If you get rid of all of your velocity, the motor doesn't respond. It chokes on the air so to speak.

The only thing cool about the throttle body is the loud sucking sound both from your wallet......

Speak for yourself. I don't make enough to support my automotive addiction now.

I thought I replied to this topic already, but whatever?!?!?

48mm.

yup