The thing to remember is that although the G11 and the other two valve per cylinder big blocks use the same engine management system as the 8V the two motors are completely and utterly different.
The 2VPC motor is essentially unchanged since its inception in 1965! Sure it's got bigger and its tune has changed but it is still, at the end of the day, a venerable execution of what was in reality an early post war design for an engine. For all of the 'It's a Hemi' advertising for big trucks the fact remains that the hemispherical combustion chamber, cross-flow head with a wide included valve angle is, if not a dinosaur, at least a very primitive proto-mammal! Something like an echidna or a platypus maybe? And like those creatures it has soldiered on long after it should of been consigned to the fossil cabinet simply because it has found a niche and filled and defended it! Don't get me wrong, I love the 2V Guzzi motor, I worked on them for thirty odd, (Some of them very odd!) years but they and
NOT the acme of motorbike engine design and design has moved on for very good reason.
Because of it's essentially 'Primitive' nature the 2V
will tend to respond much better to 'Traditional' tuning methods. Whether the parameters of the mapping system can cope, especially if running closed loop, is hard to tell but the engine will, generally, be a lot less finicky and demanding in terms of what it requires to run close to optimally than the 8V.
Does that mean that you can throw in a rock strainer air filter (Or, shudder, 'Pods'!,), stuff on a loud pipe and get it to go like a rhino with a spear up its arse? Well, no, because you are still dealing with another whole new ball game in terms of how the engine is tuned compared to an old, carbureted, linear spark, 2V donk and there ar a host more emissions regs to meet and even if you ignore them you still suffer the consequences of their having been imposed on the motor in the first place. (EG, the GRiSO, Breva/Sport uses smaller throttle bodies than the V11's that preceded them.)
The difference is that while the 8V is a 'New' design it is a strange combination of 'Old' and 'New'. While it still keeps the cross-flow head design, (Most modern motorbike engines use a downdraught design.) the combustion chamber is a beautiful example of modernity with a compact chamber and a very narrow included valve angle. This makes for very clean combustion and low emissions BUT coupled with the long duration and overlap of the valve timing and means that cylinder fill is easily compromised, charge transition, (The new charge simply galloping across the top of the piston on valve overlap and fucking off out the exhaust valves!) harmonics, (Caused by pressure waves in both the exhaust and inlet sides of the pump.) mean that the 'Old' tuning tricks simply won't work effectively!
As I keep banging on about you have to look at an engine
hollistically! Everything from the shape of the snorkel on the airbox to the volume and shape of the exhaust, the cam timing and even stuff like the back shape of the valve heads can make a big difference to how an engine pumps. It's another reason I tend to get a bit narky when people make preposterous claims for outright power on engines 'Modified' in certain ways. Sorry, you can't trump the laws of physics! A lot of things claimed are simply not physically possible! At the same time tweaking dyno figures is really piss-easy!
At the end of the day what do you really want? A fantastically enjoyable motorbike or a piece of paper you can show to other gullible fools down at the local 'Biker Hangout' showing how 'Challenged' you are?
Me? I'll be fiddlin' and ridin'!
Pete
Subject: Mapping Issues 
Mon Mar 23, 2015 2:01 pm
