DEEP THOUGHT - Anyone ever eliminated their V-Boost?

[Stites]

Hi yall, I tend to think very deeply into things - and I used to drink a lot, too - so this might be odd or just pointless ramble to some of yall.

That said, I get the idea of how the V-Boost setup works. In essence feeding one cylinder with two carbs. In theory it's an awesome setup, not too unlike a 4bbl carb on a street car. In practice, while it obviously works I see more potential with four bigger independent carbs. Bigger, as in big enough to slightly overcompensate for the loss of the V-Boost, under the idea that smoother airflow would mean more airflow in this case. More air=more fuel needed, hence big enough to slightly overcompensate.

I think that way because of those sharp corners that the "secondary" carb is routed through to the intake - it seems like it'd have a tendency for raw gas to wanna pool up in the corners(especially at part-throttle), and it'd all but have to have a certain rpm range where you'd just have an intake charge harmonic that'd make what's in the V-Boost piping just kinda sit in there and oscillate, not really offering much for power. Whereas, four bigger carbs with seamless piping to the intake ports would offer smoother airflow, a little better power output, better gas mileage, and - dare I say - easier tuning/adjustment and better rideability?

Anyone else think that way? Do I need to take up drinking again? For what it's worth I had the notion to design a dual-plane 4bbl intake to try on a V4 until it hit me that V8s with 4bbl carbs have equally-spaced intake pulses and V4s don't, which would starve two of the cylinders in a single-carb setup.

Yeah. Deep thought.:ummm:

 

[MaxMidnight]

Like most things in life you don't get owt for nowt.

Carburation is a compromise.
If you have carbs that are able to flow sufficient air to meet the requirements at full throttle will mean that they are too large at part throttle opening. The air speed through the venturi will slow down and as a result, worse fuel atomisation which will loos you power.
No problem then just make them smaller so that you get better low down power....ah but the top end will suffer.

V Boost gives you the best of both worlds - a venturi diameter that maximises power at low speeds and as the revs increase the second carb provides the shortfall that is needed at full throttle.

You are probably correct in assuming there will be some losses through the pipe-work but my guess is that the benefit outweighs this.

One of the attraction (to me) is the pulling power of the Max throughout the rev range which (IMHO) is far more useful that a hadful of GG's at W.O.T. that for the majority of the time you won't ever use unless you are draggin' the thing.

Another point to consider, there is no point in trying to get more mixture in if it can't get out so you would also need to budget for an exhaust upgrade....and while you are at it also match the ports to the inlets (at the very least).

Finally, there are those who run open V Boost.
Dyno runs that I have seen where open and normal operation have been compared show that you loose power low down with open boost. The opening point is not fixed in stone and a unit such as the Ignitec would allow you to play with opening points to find one that suits you.

 

[Stites]

If you have carbs that are able to flow sufficient air to meet the requirements at full throttle will mean that they are too large at part throttle opening. The air speed through the venturi will slow down and as a result, worse fuel atomisation which will loos you power.

If I were to ever experiment, I'd have a piece of thin sheet put in the intake piping, slightly offset, to keep the intake speed up at part throttle while keeping a resemblance of top-end power, in essence a dual-port intake. At part throttle, the slide would only let the intake charge through the smaller side of the sheet metal, and wide open the slide would open up the bigger side to let it through the whole pipe. My only concern with that would be getting into boundary layers and stuff, causing more drag on the intake charge.

You're right, though - can't get owt for nowt. For that matter, if I did something like this, adding V-Boost would give even more power, knowing my luck. Thus negating this whole thought.