Is a d15b carburetor engine faster than a d15b vtec with same transmition?

Answer 1

This question is vague at best.

Carburettors are old technology; imprecise due to their analogue nature and vulnerable to fluctuation of provided mixture unless tuned and balanced often. Carburettors also have no means of measuring air density or engine speed and therefore a true stoichiometric mix is rarely obtained in normal operational parameters. Fuel injection is a far, far more efficient method of fuel delivery on the internal combustion engine. That being said, carburettors are easily tuned by hand and do not require expensive engine management systems to adjust, and if power is the only objective, then a well tuned bunch of side-draft carburettors can often come close to fuel injection and independent throttle-bodies.

The carburettors on the Honda's SOHC 'D' engine are two Keihin side-drafts (at least they are here in the UK!), they are fairly similar to SU carburettors in design and function rather well in my experience. Unfortunately as they stand in stock form they are NOT as effective at delivering the same power or fuel economy as Honda's multi-point injection used on the VTEC engines; this is due to the computer control of the multi-point injection and the fact there is one injector per-cylinder, whereas there is only two carburettors for 4 cylinders in the case of the carburettor engine which provides an uneven charge mix per cylinder.

Finally, the choice of fueling will make far less of a difference in terms of power than the addition of variable valve timing will in this case. Honda's VTEC system allows for increased valve lead, duration and overlap at higher engine speeds, meaning it has a far superior power output than the non-vtec versions.

To answer your question in a nutshell - No.