The gsxr 1000 tb's i'm using come with a second set of electrically controlled butterfly valves, so it would be easy to just remove the one's in the middle. But you would need some way to control them.

Might test it out on the dyno once my intake is done, one run with the sec tb's closed of, and one with them open. To see if there is any power to be made, and if it would be worth the effort, of developing a management system for them.

 

I was thinking more for drivability. I think it's 23racer that has them and I have read up on his stuff as much as I can on this forum. I think it's a great idea except for the the fact all throttles open together. He said it was hard to get to idle and and part throttle and it's what caused him to bail on the factory motorcycle injector location. Forcing him back to the location on the iron.

If one could stage the throttles of these TB's and the fuel...

 

I just reread you post and think you may be on to the solution. Sticking to the point of using the purchased item as is, the second throttle plate vacuum secondary throttle is the way to go. Kinda jealous my set does not have them BUT, maybe adding something like this is easier than swapping/modifying the TB's and altering the linkage.

Sweetness! I now have more thinking to do.

 

Actually, now that we have the fueling and timing really close, the throttle transitions are really smooth. The big help was pulling vacuum from all 4 throats to smooth out the pulses. Now everything works like stock, just with more power. I did continue to use the primaries in the center iron as it was easiest and really helped with response and startup from cold. I just have one small hiccup when the secondary injectors start firing. Those bins need a bit of trimming and it will be fine.

Now I can say that throttle response is excellent, power great and the howl is awesome when I don't run the trumpet socks. It's louder than the exhaust from the drivers seat.

Works great and I would definitely do it again.

Eric

 

So, in your opinion, staging the primary and secondary throttle openings would be unnecessary?

Mine came with a vacuum pulled from all fours and a check valve. And the other goodies like a TPS.

Even though a custom intake is required, using these things bolt on (factory motorcycle injector placement) would be a huge plus to the community. They come basically ready to go if you're willing to go standalone and build a manifold.



Petterson, sorry for missing the "electronically activated secondary throttle plates" and thinking vacuum. That may actually be easier to deal with. RPM switch?

 

No, I don't think it's necessary, but you will need to go alpha n and stage the injectors. I am doing this on a 4 port 1/2 bridge and the response is pretty smooth other than the stagger through 4000 rpm as the secondary injectors start to engage. I have no idea if the setup would ever pass emissions but it does drive well and makes smooth power from about 3000 to over 9500.

Eric

 

Rpm switch should work good enough. But i tried hoking up 12v to the electric motor, 4 wires. and i could not get it to respond, so not shure how to actually get it to work.

 

I also have a set of Suzuki TB that I have plans for.
And I do think that the aux valves are run with a PWM signal.
Not sure though...

 

I am using the 4 throat hayabusa bodies. They are spaced well and fit great with a custom intake.

Eric

 

The TB's I bought are from an '01 Kawasaki ZX12R Ninja. I paid $109 plus shipping for them. They have 42 mm throats straight through, no necking down.

I edited to say they are Mikuni brand TB's.