ITB measurement ??

[Uzelac]

Where to take measure of ITB diameters ?

Someone says measure the opening, someone say measure the exit, manifold side, blade... ?

I had few ITB's passing through my hands and on neither one of them i couldn't find the measures they were specified fore.

Example.

Now i have Hayabusa's ITB's.

http://picasaweb.google.com/uzelac/Hayab...directlink

They all say they are 52mm. Maybe ...because nor opening nor exit have 52mm. Opening is little below 50mm, and exit is around 45mm.
Maybe blade ?

Earlier ITB's i used were from Honda CBR 1000RR and everywhere on internet they were specified as 44mm but on openings i measured ~41mm and at the exit they were below 37mm.

What about AE101 and AE111 from 4AGE 20V engines.
They are specified at 42 (ST version) and 45mm (BT version).
What are they real measures, do anyone knows ?

[PatrickAE86]

i've got BT itb's over here..

and the opening is about 48mm and the blade is about 45mm
the exit is a odd diamond shape thingy...

[Uzelac]

Thanks

I've searched on net, and majority says blade or exit even though many times exit ain't circle but some kind of odd design.

I'll try to measure blade of these ITB's and see where does Hayabusa and CBR's ITB's have 52/44mm, blade is the only option because neither exit or intake's are that big

[PatrickAE86]

here's a pic of my modified T3 20V itb adaptor



this is how the BT itb exit looks..

[allencr]

It's the throttle plate, nothing else, ever.