Throttle linkage / carb question

[shelby racer]

Okay, I got the mechanical linkage set up on my 4000 series cobra with the 427 medium riser side oiler with a Holley 4150 750 cfm double pumper. I have the pedal linkage set so that its throw is as short as possible (bottom hole on the pedal lever) and the carb linkage set for as long a throw as possible (on the top hole of the linkage lever) and when the pedal is fully depressed I still have about another 1/2 inch of throw on the carb side to get the butterfles all the way open. The pedal side is already adjusted to the point where any more movement withthe pedal all the way up (throttle closed) will give me and "over center" situation which jams the throttle linkage. I would really like all the throttle ( butterflies all the way open at WOT) I can get. Any ideas? Thanks.
John(;-)

[mr0077]

John, you basically want to go from pedal to carb with long-to-short, long-to-short at the rod ends...the longest lever connects via rods to the shortest lever. That way, 45 degrees of pedal will move say an inch at the other end where the first rod connects, but at the other end of the rod, that inch moves a short lever more than 45 degrees, say 60 degrees. That 60 degree rotation moves a lever at the other end of a rod the same 60 degrees, but the end of the lever (use the longest available) moves an inch and a half at the rod end, so the other end of the rod (at the carb arm by now?) moves an inch and a half...pick a hole in the carb that will put the carb at WOT with the 1 1/2 inch travel...long/short, long/short...

[shelby racer]

oaky - I think I get it and that it is the way I have it set up, but I will look at it again when I go out to my shop wed / thurs.
John(;-)

[mr0077]

John, what you described is the opposite of the long-short thing...or maybe I misunderstood your description. You said you have the shortest hole at the pedal and the longest hole (the one furthest from the shaft?) on the carb, but it should be the other way around for the max travel at the carb shaft. Let us know what you find.
Ken

[shelby racer]

Thanks for the reply. The pedal has a shaft that comes out of the far end of the foot box with 3 holes in it vertically. I have the heim jointed shaft bolted to the lowest hole. The heim jointed shaft connects to a lever (with only 1 hole) that is connected to a shaft that travels from the foot box to the manifold. On this shaft there is another lever that has two holes and I have another heim jointed shaft that runs from the top hole of that lever to the carb (that only has 1 hole) to try to maximize the length / dergee arc traveled. 3 levers (two of which have multiple holes), 1 carb attatchment poiny, 2 heim jointed shafts, and 1 solid shaft running from the foot box to the manifold with 2 of the levers (one on each end. It is like an ERA set up. I hope we are on the same page now if I was not clear before. Thanks again
John(;-)

[shelby racer]

Some one (my race car mentor) over at Nor Cal SAAC just post ed back to the same question and enlighted me on the error of my ways. I will have to look at this again wed before I have spent 8 hours in an unheated shop .
John(;-)