Originally Posted by
Raceworks
First off, the only "off the shelf" part for a Weber DGV & stand-alone ignition is the carburetor itself. Honda stopped using carburetors in the 1980's, and nobody in the aftermarket makes either a DGV manifold or a crank-fire ignition kit anyway. I did street tuning for a decade before I switched over exclusively to formula cars, and none of my hundreds of Honda customers (even the drag racers) ever asked me to pull the fuel injection from his Honda and convert it to carburetors. In fact, the drag racers went to EFI pretty much completely over a decade ago because while the initial cost was high, the cost to maintain was vastly lower.
Those low tech parts aren't exactly "cheap" either: $400 for an intake manifold, $1,800 for a crank-fire kit (Honda stopped using distributors 20 years ago), $700 for a DGV blueprinted for FF racing, or just under $3,000. Given that you'd never hope to sell more than a couple hundred units for it because the tuner crowd upgrades their Fits by putting K-series engines in them, you're going to pay at least twice as much for the parts as what you pay for them due them being essentially custom units.
Second, "EFI has better throttle response than carburetors" is complete and utter BS. I ran carburetors for a decade in Formula Mazda, and those things would bog down really badly when you came out of slow corners. After a couple seasons of frustration with it, I talked to Daryl Drummond (the engine builder for that spec class) and got some books on carburetor tuning. A season of tweaking idle jets, pump jets, and air corrector jets and I had a Formula Mazda that could idle and had crisp, immediate throttle response throughout the power band. All I had to do most times was stay on top of the main jets when the temperature changed. In other words: Tune. Your. Car.
Manufacturers didn't go to fuel injection for better performance, they went to it for fuel efficiency and to meet emissions standards.
Third, it's not "throttle response" but "torque curve." While the Fit engine sucks at top end (with the air restrictor the last 250 rpm before the rev limiter are pretty much useless), it make better torque than the Kent. The air restrictor doesn't reduce torque, only horsepower. This means certain tracks give advantage to the Fits, others the Kents, depending on the course configuration. I would not want to run a Kent vs a Honda at Carolina Motorsports Park, nor would I want to run my Honda against anyone good with a Kent at Daytona.
Slapping a carburetor on a Fit won't fix the torque curve difference for the same reason putting fuel injection on a Kent wouldn't: you've got differences in bore, stroke, combustion chamber design, and one engine benefits from 42 year of technological advancement . The last is why blueprinting makes a huge difference with Kents, minimal difference with Fits.