It occurred to me that this slide throttle is both cheaper and easier to make
than butterfly throttle bodies. Small ball bearings are about $4 each from
McMaster Carr, shoulder screws are as little as 72 cents each if bought ten at a time.
A butterfly throttle body requires shafts with expensive machining. If bought
new a single large throttle body can cost over $200. If made ten at a time
or more these low cost slide throttle sheet metal parts can be very cheap indeed.
I know of a shop in Torrance California (Talins) that can hold very tight sheet
metal tolerance with computer controlled shears, punches and press
brakes. If we get ten or more people interested I will get a quote
from Talins.

Here is a area comparison of butterfly throttle body sizes with runner sizes done
by Rino Lacombe awhile back. Two P-port 2 inch OD runners with .065 wall would have
an ID of 1.875 and an area of 2.76 square inches each for a total area of 5.52 square
inches. Actually less than the total area of an 1988 13B turbo four port.
Apparently the excellent flow coefficient of the P-port really pays
off despite having less total area.

I also checked the clearance of the this slide throttle with the water
pump. Looks like I lucked out. It will work :).

Paul Lamar

I'd be interested in a quote.

Barry Gardner
Wheaton, IL

Here are the dimensions. I changed the design to make the clearances 
adjustable. When you bolt it together you can adjust the clearance so the 
center slide moves back and fourth freely. It also lowered the height an 
inch or two giving more clearance from the exhaust manifold.

Bend up the lenght of the sheet metal according what what you need. One 
two or three rotors. Will work with side ports if you space the runners on 
approximately three inch center lines.  You will need four smaller holes in
the slide instead of two of course.

Paul Lamar
 
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