Sizes of throttle body's and whats recomended for 300kw and over?

[Guest vf20/21bg5]

Hi again,what inside diameter are most wrx,gtb throttle bodies?

And im looking at buying either a 70mm or 80mm for my build but im not sure of the bennifits 10mm bigger will make for around 300kw? any proven suggestions?

[nt_a_foz]

Im not sure about on subis but a evo i was looking at the other day that was 350 odd kw had been upgraded to i think a 100mm throttle body.

The version 8 sti one we measured the other day was 66mm interal diameter i think. Also measured a 2.5 sti one which was a touch smaller.

[Guest]

people are getting 300kw on std t/b

Anyways i tht this was a high comp high torque street car ?

[Pappu1]

can confirm that have seen a 320kw sti using factory tb

[Guest vf20/21bg5]

 Qwerty said:

people are getting 300kw on std t/b

Anyways i tht this was a high comp high torque street car ?

yes it is but i still have to do my homework as to what size throttle body and inlet ill need.....talking to guys at RACEFAB in chch whos making my plenum as we speak and they are tellig me from what im building that i should expect alot more than 300kws so i want to keep it fairly much consistant in size from were the air first enters the air filter till when it goes in the plenum,im thinking 3" all the way thru...intercooler/exhaust-rear muffler and all in between...76mm is a nice size to play with i think.

[Guest vf20/21bg5]

...any recomendations for my setup would be highly welcome as this is a first for me building a subaru semi/medium hi-comp engine from scratch throwing a turbo in the mix

[wrx_lou]

racefab make those front facing ones off trademe correct? why not just through a 100mm one on. If the standard ones will do 300kw easy then 100mm should be more than enough.

[Guest vf20/21bg5]

 wrx_lou said:

racefab make those front facing ones off trademe correct? why not just through a 100mm one on. If the standard ones will do 300kw easy then 100mm should be more than enough.

yes those are the ones,its just that bigger is not always better and may often result in exessive lagg etc so im just putting it out thr as to what people have tried and proven.....racefab sell the 70mm and 80mm ones with thr plenums

[Guest]

I had steve murch open mine up to about 72mm, works fine.

Its all about flow and volumetric efficiency,

[SILNCR]

I still had a factory intake manifold and throttle body for well over 400kw atw...