Okay, think I understand, but still wonder about the value of four butterflys over one butterfly located in a log plenum. How do your individual runner terminate? Individual filters, no filters, common log with filter? Sounds like a pure race setup.
Bill
The 4 butterflys (individual throttle per runner) idea is based on using acoustics to give tuned RAM to each cyl independently for the acoustic effects of the other cyls. Running a common plenum hurts throttle response because of the extra volume that has to get filled or consumed from the plenum as the throttles have changed.
Individual throttle per cyl allows much snappier engine acceleration for this reason.
Dual DCOE webers is ALSO individual throttle per cyl, just not injected but the same physics applies.
Individual throttle per cyl is not so exotic, most of the go fast jap cars come from the factory with it today.
Also, as to TBI, couldn't a person use two "high pressure" MPI injectors, firing either onto the butterfly or into the manifold, rather than the traditional low pressure units? Wouldn't that improve the droplet size? I'd think two injectors from a 350 cu. in. V8 would be about the perfect size.
Bill
This has been done, but injecting onto throttle plates when the plates are closed (at idle) causes puddling, and poor atomization even if the injector atomization itself is otherwise good.
My earliest work was using the large 4bbl throttle bodies that holley makes, and adding an EFI controller that actually worked.
One of the biggest probs we faced on emissions applications was the high HCs that were needed to make the engine idle. The atomization was so poor at idle a large percentage of fuel just wouldn't light off, and we had to richen the mixture to compensate for the unburned fuel getting out the exhaust.
What we learned was that if you drilled a small hole in each throttle plate on the side where the puddling occurs, the high velocity of air going through it would pull the fuel through and help to break it up. This helped, but would NEVER yield the idle quality or leanness you could achieve with multipoint, or at least under throttle injection (UTI).
The bottom line is that you really don't want to inject on a cold flat piece of metal when there is no air velocity.
Jarrid, don't agree with you about the TBI. I had a car setup with it and it was better than any carb car I've had.
Bill
I'm sure it ran fine.
Probably even had altitude compensation, which would make it better than most carbs. It wont do anywhere near as good of job of idle fuel control compared to todays port style injectors properly positioned.
I mean, whats going to yield better atomization, 2 giant 80s technology injectors squirting its throttle plates, or 8 of todays smaller injectors squirting its valves?
As for taking 2 1bbl TBIs and mounting them on a stock intake and going that route.
Been there, done that.
Swore I would never do it again.
Car was a triumph GT6, came it with SUs, left with TWM SU replacement air doors. Used off the shelf TBI injectors where each injector was sized for 120BHP. 240BHP of injectors peeing fuel (actually ricocheting off the throttle plates) fouling the air cleaners with gas, wouldn't idle worth a *CENSORED**CENSORED**CENSORED**CENSORED*.
Car smelled gassy all the time, both from the overly rich idle mixture, and the K&N air cleaners saturated from gas.
Customer wouldn't pay the bill, made us take the system off.
TWM took the TBI air doors off the market. Too much injector for the 100HP applications it was designed for. Their replacement throttle bodies are under throttle (UTI) and use 2 port style injectors each.