tinkering again

[superls]

been doing a bit of tinkering with a throttle body.

i managed to grab one from a 1 liter today from scrapyard, fingers crossed there the same as the 1.3.

anyway after completely stripping it down and taking a few measurements i decided to 'chuck' the TB, no not in the bin in the lathe lol

heres a random inside pic

and this is the diameter of the chamber a puny 45mm

let the boring commence

stage 1

stage 2

did he stop there? no he didnt, after several passes

i personally dont think it can be opened up much more, things are starting to get a little 'close'

pic of the old butterfly in the new hole

the question remains should i make a new butterfly or just cope with a real high tickover??? lol

anyway then machined the throttle shaft a bit

fingers crossed it will mame some good gains???

a quick question whats the diameter of the ga16 TB???

cheers all

 

[frank]

nice one scott (Y) (the GA ones are 50mm :grinning: )

 

[Scott]

50mm comes to mind. Dont hold me to that though.

EDIT; beaten by frank lol

 

[superls]

cheers frank, is the only benifit to a ga TB the larger bore? i would imagine it is but just checking.

 

[frank]

cheers frank, is the only benifit to a ga TB the larger bore? i would imagine it is but just checking.

yes mate, baguete had problems re-mapping the maf values of the GA one tho and gave up (then his mate bored out a CG one like yours and made a circular butterfly that kept sticking iirc (they need to be oval eh)

 

[superls]

yes there ever so slightly oval, and the edges are tapered too

 

[frank]

yes there ever so slightly oval, and the edges are tapered too

yes the leading and trailing edges are feathered eh (will need to be a snug fit eh )
i think baguete had some good gains on his

 

[whipit]

yes there ever so slightly oval, and the edges are tapered too

Should be fine if you're using on from another thottle body.

Little tip, for another gain taper the throttle body out to the inlet and to the outlet. This will help speed up the flow of the air.

Sorted some form of manifold yet?

Edit: Very nice work in the lathe, looking good.

 

[solarice]

Id be tempted to find a bigger butterfly than trying to make one, unless youve got the spare metal about (mgf for example has a 52mm opening)...wouldnt mind knowing if a larger tb would make any difference on mine...one of those things ive never tested, though the cars probably already getting all the air it can use. :S

 

[karlj]

Would you modify my throttle body? That's if you find a suitable butterfly talking of which would a ga work?

 

[superls]

ill attempt to make a 52mm butterfly first, but failing that ill check other cars see if i can pinch one.

the throttle body can be modified to say 50mm and then use the GA butterfly

 

[frank]

here,s the different butterfly,s eh, and the GA maf and also the CG and GA t/p/s

 

[r-reg-sr]

see one butterfly is oval and other isnt??
what would that be about?

 

[karlj]

the one on the left is th cg one

 

[frank]

the one on the left is th cg one

correct karl :grinning: and they both have around 1/2 to 1mm of ovality

 

[baguete]

Yes, i had one CG T/B bored to 50mm, but is a friend that has it on his SuperS. One problem that he had was the butterfly, is leaking and have a high idle (not oval shape), and other problem is that he cant go full throttle at low revs, the car becomes sluggish, but at high rpm's there is a noticeable gain. Dont know if a remap would solve that problem... fwn

 

[r-reg-sr]

properly shaped buterfly wont fix his prob??

 

[baguete]

properly shaped buterfly wont fix his prob??

Im sure it will, but that was just a test, to check if it would work, its good, but not perfect. Maybe i will do a 2.0 version of it... :laugh:

 

[r-reg-sr]

actualy gives gains---------ga 50mm-----this stock one 52mm
killer mod

 

[frank]

Im sure it will, but that was just a test, to check if it would work, its good, but not perfect. Maybe i will do a 2.0 version of it... :laugh:

70mm 2.0 ones aint they
and the GA butterfly is 49.9 x 50.4 (50.0 bore)

 

[Scott]

70mm 2.0 ones aint they
and the GA butterfly is 49.9 x 50.4 (50.0 bore)

SR20? SR20 ones are 65mm. SR16VE-N1 are 70mm :grinning:

 

[baguete]

What i meant was: "do a v2.0 version of it", not a 2.000cc version... :laugh:

 

[superls]

the cg butterfly is about 0.5mm oval, but if you measure it at an angel, the angle ov the bevveled edges it 45mm, so im sure ill be able to sort something out

 

[Zagato]

I've been planning on doing something almost exactly like this only without boring it out as I don't have all the machine tools. I even started doing a CFD analysis on it at university. Didn't get it finished before christmas hols though. When I do I'll let you know what the improvement in pressure drop is. Are you going to put countersunk screws in it as well? My guess is that would cut down on turbulence alot.

 

[superls]

yes imo countersunk screws will be a must.

 

[mckenziecz]

i got this hitachi march TB I have bought a while ago and its 50mm. think i might have to install it.

 

[Shaun]

Do it! i'm guessing we are not cutting springs today stupid snow and it's minus silly degrees!