This is an interesting topic. I never had vboost on my bike ever and have a full stage 7 with 165 mains in it. It doesn't stumble down low and will burn the wheel off from a 2500 roll on and runs 11 flat @122 all day. I have a friend with a 1570 long rod and he has always told me the bike would run better if I put the vboost back in it. I don't know wtf to do cuz it runs fine now. I guess it couldn't hurt to try. Could always yank it back out
When my motor was internally stock I ran full stage 7 no Vboost. Still had the butterflies installed to use for synching. Removed controller and servo and used throttle stop screw on cable to hold it open.
It ran fantastic that way. UFO exhaust and Stage 7, me weighing 230 geared up and it ran 11.29-11.31 & 120-121 consistently. And no bad habits at all. And I could tell Zero difference on the strip, I ran a lot of passes with the Vboost working properly along w/ the stage 7 and exhaust and the times were not any different. I guess since at the strip it never really sees less than 4500-5000 rpm anyway.
On the street I would say it may have lost a little crispness or throttle response in the off idle to 3000rpm range. But once again if I was going to "play" with someone its a simple matter of downshifting far enough to get the revs up past 3000rpm or so.
I would say that if did a 1st gear "just off idle" Roll on with someone w/o slipping/blipping the clutch to get the rpm's up I would be at a slight disadvantage.
Technically I agree with Kyles post 100%, ....Vboost open equals less velocity through two carbs since same volume is now going through two carbs instead of one.
Its not theory but fact that less velocity through carbs equals less throttle response and crispness. This is going to equal some power loss in low, mid-lo range. Its why hot rods driven on the street are more drive able, feel faster and user friendly when running a carburetor that may be smaller than what would give most horsepower up top.
As for the big motors. I think most guys end up with flat slides, meaning only one carb per cylinder. Cam overlap between cylinders is not an issue. So they don't see any issues like I had.
With open Vboost running stock intake manifolds and Mikunis all kinds of weird shit happens since each cylinder is not only getting two carbs, its also being exposed to the fluctuations from the other cylinder and its intake reversion pulses and stuff.
Not so big a deal in the stock setup.
Add high compression (mine is 13:1) and big cams and it gets a lot worse. I had all kinds of idle carb popping and occasional exhaust backfires, even just idling.
I'm not sure if my exact same motor with lower compression like the Tourmaster would have done this.
The minute I put the Vboost back to stock it started behaving perfectly.
)But it sounds like the Morley muscle kit is the way to go rather then stage 7. My vboost is working great with Sean's kit.
