The Venturi TB does increase the size behind the plate and includes a new plate.

http://www.spoon.jp/jp/products/ex/402/

-Andrew

 

I'm very tempted to see dyno's of each TB and looking at area under the curve. I have a feeling since the stock plenum is pretty small, a 70mm wouldn't hurt low end that much (assuming you port matched the manifold to the TB). I think that the Spoon venturi could, and probably would, increase mid range because of the extra flow/velocity created by the venturi.

I plan on picking up the Spoon this winter/spring, I might be lucky enough to bring my own TB if I go to Japan for TAS. I will defintely post a write up on here about it.

 

Looking forward to hearing your results.
Doesn't everything above 64mm need to be port-matched to the manifold anyway?

 

depends, I'd say you should do it for a 70mm. Technically, you don't NEED to port match it, and it also depends on which TB you go with. Obviously if a TB is 70mm tapered to 64mm at the IM inlet, it'd be impossible to port match it. Maybe a little clean up of the gasket, but I haven't had a chance to see how bad it is stock. I'll let you know if its worth the money for doing it on smaller TB's. *NOTE TO SELF* "Test smaller TB first."

 

For price and practicality, I'd get the stock TB redone to Spoon specs by AJ-R...

 

Thanks for the info.

I just saw this picture and this is the first time I see the third TB Spoon. Is there someone who can translate(roughly) the page?

 

http://translate.google.com/translate?hl=e...products/ex/402

^Google translate works decently.

 

ehh...I still think that a TB that is one size all the way through will probably net the most power

 

Silver - Even if it's narrower all the way through than another? I mean, 62mm all the way through, or 62 at one point and 66mm at others? What do you think? JW...

 

Ohh no, if its 66mm at one point and narrows to 62mm but then opens back up to 66 ie the Spoon Venturi then yes it should be better then something that is 62mm all the way through. But say the J's which is 66mm all the way through, I think that would be better then something like the Spoon Venturi.

The whole idea of a venturi was for carbureted cars...the fact that the air speeds up and creates a low pressure in the narrow section made a suction that would pull the fuel out of the float bowl...we have no need for that IMO in the TB, sure the air will speed up right there, but the as soon as it gets past it, it will slow right back down.