V11 Sport (Scura) All Std to Pipes and Mapping - Written Feb ‘05

Steve our spare parts man (alleged “parts king”) is something of a Guzzi fellow. Prior to coming to work with us he restored a T3 (Cali?) to concourse that he was rather proud of. When he started with us his daily ride was a light blue SP1000, in not overly poor condition (surprisingly), but not too flash. Much like Steve, although probably less abrupt or responsive. Then he managed to get his hands on a Lemans 3 we traded that had dodgy paint, but seemed otherwise not too bad. It had been sitting for quite long time, but Steve just gave it a quick check over, put a battery and some fuel in it and off he went. It did get stolen at one point, although it was found a few days later leaning against a tree not far from the scene. Obviously the intending thief had wondered what the hell they’d got themselves in for and cut their losses early. As you would.

But, just when we’d settled into laughing at Steve and his Guzzis he up and bought a new one. A Scura no less. Lots of remarks were made about the Italian meaning of the word (and the potential going to waste on our man Steve), but he was well happy. After it’d done a few km we gave it a service, went for a ride and ran it on the dyno.

At this point I must say I was most disappointed with the way it rode. It was without a doubt the best running injected Guzzi (apart from my Sport 1100i after we’d played with it) I’ve ever come across. Almost faultless. Amazing. I hadn’t really ridden any V11 up to that point, but have been on quite a few since and have found them all to be rather nice. Once set up properly that is. Some of them have been rather unpleasant when they first arrive, but with the basic set up and tune they really are a nice running bike. Even with aftermarket mufflers and the std ECU.

And it went very well too I thought. The acceleration was much better than I was expecting – I’m told the flywheel is quite light compared to previous models. So off I went to the dyno to see what it had. As it turned out, not as much as I expected.

We ran the bike all std, then removed the little air snorkel thingys from the air box entry tubes. Which made a little more noise and gave maybe a tad more mid range to top end power according to Steve. The graphs below show power first, then torque and thirdly acceleration time. I’ve included a couple of ring-ins for the comparison. Green is the V11 all std. Red is with the air snorkel thingys removed. Blue is my Sport 1100i all std, and yellow is my R1150R all std. The R1150R has the advantage of an extra valve of each per cylinder and maybe a little more compression. Gearing wise, all are run in 4th gear. The V11 and the R1150R are pretty much the same, whereas the Sport 1100i is about 20% taller. Which is why it doesn’t accelerate as fast.

Dynograph courtesy of DYNOBIKE (03) 9553 0018

Dynograph courtesy of DYNOBIKE (03) 9553 0018

Dynograph courtesy of DYNOBIKE (03) 9553 0018

You can see the sport 1100i made much more midrange, and the R1150R just whups ‘em. Although the R1150R is very much tuned for midrange performance at the expense of top end. The one thing that stood out about the V11 curves is that it appeared to be either over-cammed or to have retarded inlet closing. The fairly shallow angle the power curve has from 5,700 RPM to the peak at 7,800 RPM, and the flatness from there to the 8,500 rev limiter is something that surprises me. Usually a cam limited engine will have a much steeper fall of the torque curve after the peak. The V11 torque peak is actually 800 or so RPM lower than the Sport 1100i, but it holds the falling torque much better. I haven’t really investigated the changes from Sport 1100i to V11 – I thought they were much the same apart from exhaust style – so this interested me. Although I wasn’t getting too carried away with theory till I’d seen the open exhaust curves, as maybe the std exhaust was contributing somehow.

So then we fitted a set of Leo Vinci carbon mufflers (Steve was splurging) and went back to the dyno. And, once we’d done that, we fitted a Stucchi x-over. A nice x-over that replaces the original stamped and welded piece, it’s an X style where the two pipes come together at the centre and then spread out again. So it’s a full flowing, ‘collected’ x-over, where the exhaust from each cylinder can use both mufflers - as big twins seem to like. The next set of graphs show the results. All runs are with the little snorkel thingys removed. Green is std mufflers and x-over, pink is Leo Vinci and std x-over, blue is Leo Vinci and Stucchi x-over.

The improvement in performance is clear. The main effect of the x-over is from 4,500 to 5,500 in power terms, but the change in air fuel ratio suggests that more fuel would bring even more power for most of the RPM range. Fitting the mufflers alone gives a very good improvement for most of the range, with a real jump from 3.500 to 4,500. It is certainly a much better improvement in peak power than I achieved with my Sport 1100i.

At this point we’ll do something of an x-over comparison. Another customer bought his V11 in for a service and x-over, but this time we’d ended up with a Mistral x-over, also known as the ‘Agostini’ x-over. Looking at it I could tell it was going to cost top end, simply because there’s no flowing collector. There are two short (50 – 70mm) tubes joining the two pipes, one oval and rather large, but exhaust gas doesn’t slow down, take a 90 degree left then right and continue on its way. So it doesn’t work. As we also saw with an experimental Ducati S4R cat replacement pipe.

But, I had to dyno it to prove this to everyone. Although, I remembered Doug Lofgren’s stuff he published maybe a couple of years ago now on these, so I had some prior proof. In Doug’s results, which included custom mapping using Duane’s Ultimap 15M software, he found the Mistral x-over gave a good midrange improvement, but cost quite a bit of top end. I didn’t find anywhere near as much midrange, but we also lost less top end. These results are shown below. Power first, then air/fuel. Green is the std x-over, red is the Mistral.

As you can see, the Mistral also causes some leanness, but this doesn’t last for the whole RPM range, going rich at the top end as the power suffers. I didn’t bother tuning it at all, as there’s no way a customer’s going to pay for something that costs him 6 Hp. You may find the Mistral could be tuned to give a nice midrange increase (Doug has maps), and this may suit many riders who really don’t get into the high RPM range very often. But, this owner was heading to Phillip Island the next day for a track day so giving away top end wasn’t in the game plan.

Next we went back to Steve’s bike to try some tuning. There is now an ECU available from Moto Guzzi under the ‘Guzzi Performance’ tag. Duane had the map so he flashed that into an ECU for us and we tried it out. Steve’s feedback was that it went nicely tooling around at low RPM, pulled hard at WOT down low and was much, much stronger from 6,000 RPM upward. But it had a rather odd hole or flatness around 4,000 RPM in most situations. Wacky.

I’ll finish here for now, and will complete this report when I have more info.

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