dunkd

hello. built 84mm gsr lookin for ~400whp. right now i have the JG/Edelbrock Intake Manifold and looking for which throttle body I should mate up with it. I was considering having my GSR throttle body bored out to 64mm by maxbore but i dont think thats gonna be big enough? any input is appreciated thanks.

PrettyLude

try a 68mm from str, or they even have a bigger 70mm throttle body

RyanEJ8

What size is your charge piping?

Forrest Gump 9

Stock one should be fine. the 64mm is better. I wouldn't go bigger than the diameter of the charge pipe though.

RyanEJ8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo9Nut &raquo;</TD></TR><TR><TD CLASS="quote">Stock one should be fine. the 64mm is better. I wouldn't go bigger than the diameter of the charge pipe though.</TD></TR></TABLE>

That's what I was getting to when I was asking his charge piping size.

PM-Performance

watch out with bored TB's alot of places do shitty jobs on them and they get wierd idle and stuff from air seeping past the butterflys when you dont want them to.

I used my stock R TB and it worked awesome. for 400whp, you seriously dont even need an IM , but it will make the goal get reached a little easier

m R g S r

Yea, I'm gonna use my stock GSR TB for 500-550 whp

80884

"Your turbo piping on a sophisticated turbo setup is probably 2.5 inch pipe most likely. All the street legal kits I have seen are smaller at like 2.25 inch pipe. People, huge throttle bodies do NOTHING on turbo motors. 2.5 inch pipe is 63.5 MM in diameter. But still, that doesn’t even matter because as long as your intake manifold is pressurized, the engine doesn’t know the difference. Your boost gauge is hooked up to your intake manifold right? Does it read a steady 10 PSI? Then that means your intake manifold is a steady 10 PSI, so why is a 70 MM throttle body going to do a damn thing? Get the picture?"

I didn't write that, but that is what I was told. I'll be using my stock GSR TB as well.

dunkd

i have 2.5" charge piping.

RyanEJ8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dunkd &raquo;</TD></TR><TR><TD CLASS="quote">i have 2.5" charge piping. </TD></TR></TABLE>

No need to bore the tb then.

1SlowSi

bringin this back up. So you are you saying that you shouldnt have to bore a stock throttle body with 2.5" IC piping and Edelbrock IM?

rioninja

Yes because the stock throttle body is already just about as big as it needs to be.
ie: the size of teh charge piping.

g2turbo

good topic... I plan on running a stock GSR throttle body as well. Many cars have made 5-600 on these stock throttle bodies. With that said im sure there can be more power made with the larger unit.

MrBui

got mine done here http://maxbore.com/ no problems with idle

CRVRX

As long as your thottle body isn't smaller than the charge pipe your OK, Going bigger won't hurt. Also make sure when going with a larger thottle body, you manifold is at least that size or bigger.

1SlowSi

im not what my stock Si throttle body is, but i have 2.5" IC piping which is 63.5 mm. A JG TB is 64mm I believe. Damn thing is $330!!!

YAMAHAtrueracer

i'd get a BBK 70mm if I were you, the run like $300 give or take a lil' and works great. I have one and don't have any cons against it

Sinitron

STR 68 is a perfect fit on my JG/Edel manifold. worked out great for me...

raene

The throttle plate causes the throttlebody to act slightly smaller than its open diameter would imply. I think to maintain the same flow without having a restriction you'd actually have to run a little larger than the charge piping.

jDMJeRk

spaceballs does some nice work for 100 bucks to your stock tb, thats the route i took!