Crank & cam sensor Buell 1125

[katana]

This is a blown V twin with turbo still huffing but with the plenum not connected as picture? That would explain the MAP sensor readings - large volume of air from turbo can't fully pressurise the inlet due to gaps but can't leak sufficiently so 1-2psi isn't impossible.

[Rob Stevens]

Is the pressure sensor located down stream of the butterfly? Are there 2 butterfly's one each head?

[Alex DTA]

There's a fuel compensation doing odd things. Look at how the injection times increase and decrease.

When it kicks in at 8300 RPM, your AFR drops to the low 10s, and some dips below that.

The MAP sensor readings aren't great either.

[stevieturbo]

Would be nice to be able to log such compensations to see what they were doing

MAP sensor is the main issue here, and you could probably revert back to 10Hz logging to resolve that, which would allow a few more items than 100Hz does.

[Rob Stevens]

looking again the map sensor is not just wrong it doesn't see the throttle closing, it should see a massive vacume

[stevieturbo]

It's maybe installed prior to the throttle blades ?

Either way, it's all wrong in every respect starting with the base calibration.

[blownharley]

Hi and thanks for your inputs.

Just to clarify, this is a turbocharged engine and the MAP-signal is taken from the plenum before the throttle bodies. And yes there are two rather big throttle bodies on this engine. Without boost I'm only using the MAP-sensor as pressure compensation for changes in barometric pressure. So Alpha N due to the large throttle bodies with boost compensation from the MAP-sensor.
The log file 2 and 3 is without the plenum attached to the throttle bodies and there is a gap of about 30-40 mm between the TB's and the plenum. I guess this would smoothen out the pressure peaks a little bit more than what I can see here. I will try to change the filtering of the signal from 5 to 45% and see what happens, thanks for the suggestion!

Unfortunately the neighbors weren't too impressed with the runs on my outdoor dyno the other day so I need to fit some kind of muffler to the bike before testing again.

[Rob Stevens]

It will never work like that, you need to compensate for the pressure on the back of the inlet valve, not somewhere else on the bike
Let me guess this is an American idea like 16v battery's
Oh and the filtering function is a smoothing over time in ms not a %
Also your fuel PRV needs to reference the air pressure where the injectors are.

[blownharley]

Rob,

I have a FPR taking the signal between the TB's and the inlet valves.

Please explain why this wouldn't work since I really don't get this? The FPR corrects for the delta pressure between fuel and manifold as far as I understand?

When it comes to the filtering function I was not aware of it is a compensation in time since the manual (page 94) doesn't say this.

[stevieturbo]

If you are taking MAP compensations from above the throttles...I would also take FPR signal from the same area

And ensure both are damped and giving smooth signals.

But again...the MAP sensor does not even appear to be caliibrated correctly given the readings shown.

In general I dont see why how you have it configured could not be functional though.

How much boost do you intend to run, and what sort of base fuel pressure are you currently running