Quote:
Originally Posted by dwtaylorpdx
They are called Slide Valve throttle bodies, been around for quite a while.
Some Methanol sprint cars, F1 cars and some Euro dirt cars run them.
Lucas made one of them.
They are very very effective in situations where you want throttle response.
Dave
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No, they aren't [that type of carb]. Still can't find an example of it, though, and I don't even have the DVD of the last show I saw them on... (part of power block from back in the day).
The throttle valve is still actuated the same way, with a cam, except it's a half-circle port with a half circle throttle blade that tucks into the port at WOT. Air doesn't split to go around it, because there is only one opening in the throttle port. It has a much lower Cd than traditional throttle assemblies because of this, but a larger throttle cam is required for more precise throttle response, because if the same size cam is used, you're only able to get half the airflow that you'd be getting at a given RPM/throttle setting with a normal carb.
The other design that I thought was better even than that one, is a square throttle bore with two gates that open apart from each other in the center. It uses a single throttle cam and a pair of cogs. The throttle cam controls one plate, the cog opens the other plate to the same angle at the same time, but they both open the same port, and close together when the throttle is closed.