jiffthejiffmanjaffa

iTrader: (10)

I'm currently in the process of building a 2.5 engine with Version 4 STi heads. I'm looking at all the other bits that need to be changed/could be change at the same time.

I saw this today and wondered if it would fit, and do any good?

Subaru EJ20 2.0 16v Turbo - Performance Throttle Body (2) - £45.00 : Headtune - Performance Cylinder Head Gasflowing, Porting & Polishing

Has anyone got a pair fitted, did it make any difference or is it a waste of money?

silent running

Well I did a similar thing when I had mine off a couple of years ago. A lot of what's on there can be done with carb cleaner, a drill mounted flapwheel and by swapping the spindle screws for round headed ones. Now if they were going to overbore the throttle tube and then give you a bigger plate from a larger throttle and make it all work, then yes that would be worth £45.

I suppose if you want a cheap pocket money mod, stuff like this all helps, even though it might only be a small change.

The rookie

iTrader: (1)

As for helping low to mid - what guff, its least likely to have any effect at the lower airflows at low engine speed, and the TB is a lot less restrictive than the intercooler (by a factor of about ten) anyway....save your money or DIY it!

Simon

silent running

if you're going to the trouble of swapping it out, you might as well do the work yourself, it's all obvious stuff really. Look at how the airflow passes through with the throttle plate wide open and smooth it out. Main culprits are a slight step in the opening to the tube, the spindle screws and the chunky edge to the leading part of the throttle plate, plus the slightly rough finish to the tube itself. Be careful with the throttle plate though, you don't want to knife edge it so much that you end up with a leak around the edge when the throttle's supposed to be closed.