Surging: an outsider's view

Right then. This is the stock Aprilia Futura map. We call it the 05 map is it's called 180905. It came out in '03. The big difference between the previous map are the increments in throttle position. You'll notice in the left column where it says 'TP' (throttle position) that there are 8 steps from zero to 21 degrees opening. Whereas the old map only had 5 or so. This means that the fuel injected at 3 degrees can't vary too much from that at 5 degrees and so on. Or you get a jerky throttle response. Which the previous map had.

I added the graph. This illustrates how the map could be written by Aprilia, limited by the engine characteristics, position and sensitivity of sensors and stock exhaust system. The map is rich compared to the old one - poorer mpg - but the bike runs so much better with it.

The full exhaust system my mate developed and I marketed for the Futura can be run with the stock map. That's because the ECU can compensate within certain parameters built into the software to compensate for high altitudes, rain etc.
Of course with Tuneboy you can optimise the fueling and that's how these trims were applied. On AF1's (host of apriliaforum.com and reputable tuner shop in Texas) dyno on a Futura with the BEF (Belgian Exhaust Factory) full system. I'm not trying to advertise here btw: BEF has ceased to exist, not for lack of sales I might add.

My bike gets loads more fuel than these trim at high revs. It also has an air kit to replace the stock airbox and is probably the only Futura to do 262 kph on the road, not just on the dyno.

Now then, the SD '06 map. Look how many increments you have from zero to part throttle! And it's snatchy?
The graph looks very linear with the obvious noise-related leanness almost all bikes have. More fuel on top makes it pull hard in high revs. Apparently.

The map for the '06 with Akra full system according to the Tuneboy website.
Notice much difference?
It's richer but has pretty much the same characteristics as far as I can tell.

Now the '07 map for stock bikes with stock cans.
What has changed compared to the '06 map? It looks smoother but then so the '06 map looked pretty smooth too.
I should have turned off the graph but it's too late to redo that today.

And the '07 map for 'Akra pipes'. Is that a full system or just cans? I can't tell from the Tuneboy site. It's not all that much different from the stock one.

Well I for one am back after our ride in torrential downpour to and from my dealer QMS. We're in Belgium by the way.
I just got the call of how the bike rides now but I'll give you the story first. I highlighted the issue in case you can't be bothered to read the whole thread. I totally understand.

First the bike went on the dyno to get a feel of how it acted. The mechanic felt the transmission to be very clunky and adjusted the chain and excessive play in the twist grip and did another run.

Meanwhile my dealer - who is very well connected worldwide - made a call to the UK and got a call back from Bracken, apparently one of the largest and most knowledgeable KTM dealers in the UK. Now Bracken says there is no such thing as a 'wonder map', even with Tuneboy. The angle of the throttle bodies, the way they sit between the cylinders pretty much defines how the engine behaves. So as suspected, the OE map is pretty good.

Back to the mechanic who checked throttle body synchronisation. He found they were set up the same way as an Aprilia RSV so with a small difference in pressure. So he decided to leave them alone.
Especially because, and here it comes: one of the velocity stacks was completely detached from the TB and the other one was loose! Could these have come loose by themselves we asked? No way says he.

Next he took it to the road and found it rode very well. RSV-like injection-wise were his words.
As we were a bit curious about the power and torque he did another dyno run and the results are 119hp and 100 Nm (DIN, not SAE for the yanks on here) at the crankshaft. This is a Fuchs dyno. Very accurate and never exaggerating. You want more power just take it to a Dynojet dyno.

I just got a call from my mate who survived another 20 miles of congestion in the pouring rain after I left the motorway and the bike definitely feels better and smoother. He thinks adjusting the chain slack makes a bunch of difference. I know I can feel 5 mm too much in my Prillers pretty well.
In first gear, you know when you're filtering and are right on the verge of flicking it into second but not just yet , meaning very little throttle but rather high revs for that bit of throttle opening, that's where he felt the bike wasn't quite perfect. All other gears, smooth and responsive.
To be honest, my Tuono doesn't like that kind of riding in first gear either.
It's just a lean condition and can be corrected on the SD with Tuneboy if one absolutely wants.

The little rattle under the tank I also heard when I rode it is also gone. Velocity stacks bouncing around in the airbox no doubt.

So there you go: that was the particular problem with this bike: a sloppy mechanic.
My dealer's mechanic says he can experiment with the TB synching further if needed, ie put them on the same pressure. He also suggested putting in the dB-killers in the Akra cans to see if that improves anything.

On a personal note I think getting more power out of the SD is a matter of making the bike breathe better. Breathe in AND out. The stock exhaust system doesn't do much to persuade both cylinders to help each-other ( I took a close look: not much of a crossover section and furthermore a 2-into-1 system). Cans alone don't make much difference in my experience, maybe 2-3 hp if that.
I haven't had a chance to take a look at Akra's full system but let me remind you they've made crap stuff before and it doesn't look like they have much competition when it comes to SD full system exhausts. Correct me if I'm wrong.

My Tuono - Arrow full 2-2 system and different Eprom - delivers 115 Nm of torque and 132 hp. I don't use the peak power much. I ride the torque wave.

Deets, did they post proof by chart or by numbers?