Mixture Bracket
Airflow Performance supplies a set of brackets for their RV-6/7/9 Fuel Injection kits that are beautiful works of anodized art. Unfortunately, they interfere with the engine mount/nose gear structure for the "A" models. I contacted Don Rivera at AP and was told that they don't have brackets for a nosewheel model because they haven't worked on one at their shop. Fair enough, so I set about working up my own brackets.
The throttle bracket is simple enough. You could trim the supplied bracket down to clear the mount but I hated to cut and file that beautiful bracket so I fabricated another one from 1.5" x 1.25" angle. It only needs to be four inches long and has an angle tab riveted to it to hold the cable as described in the installation manual for the original bracket.
The mixture bracket is another matter. I tried several different routings and the one that made the most sense for the cable was to pass it under the mount tube that braces the nose gear and then penetrate the firewall just above and to the side of the nose gear mount itself. This meant that the bracket had to pass over the mount tube and then down behind it. I accomplished this by using two pieces of angle riveted at right angles. I was a bit worried about the moment arm of this piece but once it was drilled and clecoed it proved quite sturdy.
Since the text description is a little vague, I'll follow it up with pictures:
The above photo shows the throttle body on the spacer with the brackets attached. You can see how simple the throttle bracket is and the angle tab for holding the cable. You also get a good look at the backside of the mixture bracket.
The above photo shows the throttle body from the mixture side. You can see that the bracket is canted inward. The cable attachment has to be in line with the bolt holes in the anodized spacer (you'll see why soon). I could have alternately put the flange to the inside and canted it outward but then the cable would run from the inside of the bracket and I didn't like the potential for interference. Between the ball link on the cable end and the cable's ability to swivel a few degrees, there's no interference or friction here.
The above photo shows the brackets and throttle body spacer mounted on the sump. The view is from the throttle side and you can see there is plenty of clearance with the throttle bracket. You can also see how the mixture bracket fits over and behind the engine mount tube with plenty of clearance.
The above photo also shows the brackets and throttle body spacer mounted on the sump. The view is from the mixture side and you can now see why the bracket had to be canted inboard. The bracket needs clearance from the hanger for the Vettermann exhaust and the cable, in any case, needs to snake inboard of the standoffs for the lateral hanger and then under the lateral hanger and up along side the nose gear mount. Trying to angle the cable so it could go over the first mount tube would have either made too great an angle to meet the control arm or would have needed to route the cable up toward the accessory case, uncomfortably close to the fuel pump. Just for my peace of mind, I had an A&P friend look at it and he couldn't propose a better solution.
The above photo is just another view of the bracket for perspective.
Since I already did all the measuring and fitting, I'm including a dimensioned drawing of the mixture bracket (the throttle bracket is made from the same stock, 4" long). Obviously, this is not an official Airflow Performance solution, though they are welcome to run with it. I am offering it freely for individual use, in case you have the same setup. On the other hand, I reserve the manufacturing rights to these brackets. Unless you receive permission from me, you may not manufacture these for sale. I hope this helps someone out there.
