by Craig Hoskins » Mon Nov 03, 2014 8:00 pm
Bill,
I installed a Rotec TBI on my Sonex tri-gear 1537 and have over 30 hours on it now. I installed traditional vernier push-pull cables. I really like the accurate control of throttle & mixture. The air filter in the filter box is 4-in OD by 2-in thick. I have both carb heat & ram air through a damper to select which I want. The neat thing about the Rotec TBI is that it automatically adjusts for the increased ram air to maintain proper mixture. (Sonex recommends against ram-air with their AeroCarb TBI because it changes the mixture) My caution to you would be that the comments Rotec makes in their information is that you are responsible for the intake system to the engine to make sure equal mixture gets to each cylinder so they run balanced and not one rich and another lean. I had to build a new intake manifold to improve the balance since the spray bar is not symmetrical in the throttle body. I have two fuel pumps, but found out that it still runs fine from gravity from the main fuel tank. I'm very pleased with it's performance. I fly with much more confidence now. Good luck with your project. I posted some pictures for you under: Picture/Album, Sonex no. 1537 (Craig Hoskins)
Happy safe flying,
Craig Hoskins
Sonex 1537, Tri Gear, 145 hrs
GPAS 2276cc VW, Rotec 34-2 TBI, Prince P-tip
GRT Sport SX EFIS