[cyclecamper]

OK I have slightly bored-out throttle bodies that are also cut shorter at the top. Worked well on the seller's race bike they came off of, but everyone who has used shorter TBs has reported a loss in low-RPM torque and reagarded it as a race-only mod.

I'm considering lengthening the TBs, but at the other end. For one thing, I can probably then use my stock airbox again. The tops were cut off, now I'm thinking of adding to the bottoms. This will effectively move the injectors farther up-stream, and move the butterflies up-stream. The effect could be significant. I'm educated in acoustics and computer modelling of acoustical structures, so I'm not looking for a wrong lecture on the effect of making it shorter or longer...but I'm really still interested in all opinions, especially about whether there will be an noticeable throttle lag from moving the butterflies up-stream, and whether there will be any improvement in atomization from moving the injectors up-stream or will it have worse hesitation when I roll-on with more fuel condensing and raining out below the butterflies, etc.? I know more or less what longer runners do on a car engine; I know Ducati and the Yosh LTR racebikes were successful with secondary overhead shower injectors.

This is for my "future engine" I've been accumulating parts for but never even opened up yet...essentially: J&E high-compression ceramic-coated pistons w/ anti-friction oil-retention coated skirts with stock bore, Vee-Two cams w/ adjustable gears, slightly lightened alternator rotor, balanced crank nearly stock weight, Yosh/Carillo rods, modified ECU w/ 900 more RPM with soft & hard limiters intact and more ignition advance near redline and software TRE, Ferrea ceramic-coated stainless valves with anti-friction oil-retaining coating on the stems, cryo-treated stock valve springs. Bike has bigger aftermarket ram tubes, Yosh full system.