The bog stock standard SFC1000 delivered 95 ponies (+/- 2, usually +2!), consistently, which isn't bad at all taking into account that the bike met current german regulations at the time. The Moto Witt dyno verified these figures many times. As a matter of fact, we always stuck a SFC1000 on the dyno when an unbelieving Guzzi or Ducati owners' bike failed to fulfill expectations! 
The unbeliever could choose which one if we had more than one standing around... he then realised why he hadn't stood a chance against a standard triple on the road.
I remember one particular example that had its exhaust system only replaced, it pushed out 104... This exhaust system wasn't even very "scientific", with a bit of fiddling this figure could well have been improved on. Where does that put the gain from your carbs Lothar, if your exhaust is truely optimized? I'd say, just a little extra, all that can be expected without seriously re-working ports and valve seats and swapping cams.
A more efficient exhaust will create a higher vacuum in the system and extract exhaust gases from the combustion chamber, thus creating an over-filling effect which in turn results in a bigger bang, even with the smaller 32mm carbs. This can be further increased with an appropriate choice of valve timing/overlap. The 120? configuration is also a considerable aid, giving even firing impulses and therefore even and consistant vacuum in the exhaust, which explains in part its comparitively smooth and consistant power delivery across the entire rev range.
The small carbs in reality do not create a "bottleneck", they are in fact a venturi and speed up the charge compared to larger carbs at low- and mid-range, they are slightly lacking in size at the top-end only. The boys in Breganze really knew what they were doing imho. You are correct in assuming the carbs were already homologated, in fact, the SFC was certified with the RGS homologation... :
With your 40mm carbs, you are experiencing a serious drop in air velocity at the mixing chamber, highest air velocity will be somewhere mid-way down the intake port near the valve guide where the port cross-section tightens up slightly. Without attention to the cylinder head, you will not fully exploit the capabilities of your carbs.
Lothar, we can stick our bikes on a dyno back-to-back this winter if you like. I know of a place that charges ?30 for a series of runs, easy no-hassle booking. Oliver will probably come along with his 980cc (he puts a lot of emphasis on that!)Beemer too, that'll open your eyes!
Rant well and truely over (I suspect we're boring everybody),
piet :-*
The unbeliever could choose which one if we had more than one standing around... he then realised why he hadn't stood a chance against a standard triple on the road.I remember one particular example that had its exhaust system only replaced, it pushed out 104... This exhaust system wasn't even very "scientific", with a bit of fiddling this figure could well have been improved on. Where does that put the gain from your carbs Lothar, if your exhaust is truely optimized? I'd say, just a little extra, all that can be expected without seriously re-working ports and valve seats and swapping cams.
A more efficient exhaust will create a higher vacuum in the system and extract exhaust gases from the combustion chamber, thus creating an over-filling effect which in turn results in a bigger bang, even with the smaller 32mm carbs. This can be further increased with an appropriate choice of valve timing/overlap. The 120? configuration is also a considerable aid, giving even firing impulses and therefore even and consistant vacuum in the exhaust, which explains in part its comparitively smooth and consistant power delivery across the entire rev range.
The small carbs in reality do not create a "bottleneck", they are in fact a venturi and speed up the charge compared to larger carbs at low- and mid-range, they are slightly lacking in size at the top-end only. The boys in Breganze really knew what they were doing imho. You are correct in assuming the carbs were already homologated, in fact, the SFC was certified with the RGS homologation... :
With your 40mm carbs, you are experiencing a serious drop in air velocity at the mixing chamber, highest air velocity will be somewhere mid-way down the intake port near the valve guide where the port cross-section tightens up slightly. Without attention to the cylinder head, you will not fully exploit the capabilities of your carbs.
Lothar, we can stick our bikes on a dyno back-to-back this winter if you like. I know of a place that charges ?30 for a series of runs, easy no-hassle booking. Oliver will probably come along with his 980cc (he puts a lot of emphasis on that!)Beemer too, that'll open your eyes!
Rant well and truely over (I suspect we're boring everybody),
piet :-*
NEVER!! Time has just gone 40+ years down the road and tons of new technologies have been developed. Or how else could we today squeeze 15HP and similar torque out of the same engine by just altering the exhaust system?
