In 1980, Cycle Magazine published 1980 GL1100 Standard 12.47 @ 107.39.
https://www.motorcyclespecs.co.za/model ... g%2080.htm
This page shows "various sources" suggesting late model six-cylinders anywhere from 11.9 (Valk) to 14.1.
https://www.zeroto60times.com/vehicle-m ... times/a-z/
And there's:
GL1000 13.47 seconds @ 104.00 mph
GL1100 12.47 seconds @ 107.39 mph
GL1200 13.11 seconds @ 96.2 mph
GL1500 13.52 seconds @ 96.1 mph
GL1800 12.14 seconds @105.92
None of these identify the date, location, altitude, ambient conditions, etc., so they're worth exactly the same critical accuracy as a 'rear end dyno'.
I have tested My GL1200... on a 68F morning, it will go from home to office in 22 minutes with my lunch bag, briefcase carrying two laptop computers. If I forget the briefcase, lunchbag, and computers, it takes about 35 minutes.
When an engineer who's designed Formula One V12's designs a flat-four engine for a comfortable heavy-touring motorcycle, he's more interested in setting records in odometer readings and smiles-per-gallon.
If you spend lots of time calculating, experimenting, changing, and repeat, you can come up with tuning that creates a powerband with a high peak, and hence, a high boasting number on a dyno graph. That happens because the harmonic resonance of the intake, exhaust, and chamber are at an appropriate crossing point where differential pressure from the intake and exhaust port is highest. In some circumstances, the differential pressure can be up to 20% HIGHER than atmospheric pressure, and this can be observed on a manometer, while performing a dyno pull. The side effect to this level of tuning, is that the OPPOSITE case (lowest differential pressure) appears at some OTHER point on the graph, and as a result, the torque band is basically gone. The last side effect, is that when you get to that crossing point, the cylinders OVERFILL... meaning, there's sufficient differential pressure that when valve overlap occurs, you're pushing all the exhaust, and part of the intake charge out the exhaust pipe. At this point, any additional flow is just wasted out the tailpipe. Shortening up the overlaps mitigates this, but at a total loss of tuning's advantages.
When you place a fixed-displacement supercharger on an engine, and belt it to that same engine at a known ratio, all the tuning work goes right out the door, because it's not a tunable volume... but the side effect, is that no matter WHAT speed you're going, if the engine is actually 'running', there is ALWAYS substantially high differential pressure between the intake and exhaust ports... and shortening up the overlap prevents dumping precious fuel energy out the exhaust.
From an output perspective, there is no replacement for displacement, and adding a supercharger increases the effective displacement in fuel-air volume by a very static ratio. Betting a naturally-aspirated engine of ANY tuning level, against a supercharged equivalent, is playing Russian roulette with a fully-loaded Glock 19. Putting 7.5psi of boost on an engine is the functional equivalent of increasing it's effective displacement by 50%.
The only advantage the naturally aspirated engine has, is a little bit of weight, which again, is ratios... add 6lbs of weight, to get 400lbs of performance, the math is pretty clear. The other aspect, with respect to acceleration and standing-start times, is that every ounce of weight is important. The fastest, easiest, cheapest way to make a motorcycle faster, is to get off the bike, and have a smaller, lighter guy get on.
But this is very irrelevant to the realm of my GL1200. It'd be faster if I took the brake fluid, toolbag, change of clothes, rain jacket, and extra helmet out of the bags, but I'm not gonna do that. My greatest specs and calculations is that I bought 3 years ago for $1200, and it had 11,000 miles on it, now it has 20,000, and I'll get another season out of the tires if I'm careful, the clutch slave cylinder stopped leaking shortly after I purchased the rebuild kit (and it's still sitting on my desk...)... the stereo blew a fuse in a rainstorm, and it's a bit cold-blooded, rather thirsty, but starts every day, and isn't 'needy' of attention.
