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PostPosted: 21 Apr 2015 20:41 
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Current ride: S1W,Hype,HP2,R1200RS
Location: Preston, Lancs
I have had the opportunity to ride a couple of new bikes in the last week or two; Ducati 899 and a couple of VFR1200s (DCT and manual).

Though the VFRs were relatively good the fuelling on all three was not good in the lower rpm ranges The Ducati was especially odd coming into and away from low speed junctions and roundabouts. The 899 was excellent higher up the rev range and would have been great fun on a track......but I doubt many will spend a lot of there time at trackdays.

In comparison the X1 today was crisp, clean and torquey at road speeds/RPMs.

Are the emissions and noise regs making it impossible for manufacturers to make the FI work well at pottering about RPMs? Or are they all just tuning the powerplant for peak power to make the punters happy?


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PostPosted: 21 Apr 2015 20:54 
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proff. patpending
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Current ride: Victoria Sponge
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My SP2 is smoother than I remember my 1125 ever being... But maybe that isn't the fuel injection and more the cams and pipe, none of the chugging and rattling at below 3k...

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PostPosted: 21 Apr 2015 21:13 
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Current ride: S1W,Hype,HP2,R1200RS
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The low RPM behaviour is one of the reasons that I got rid of my 1125 (and my RC8)......


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PostPosted: 21 Apr 2015 21:18 
jeznewsome wrote:
The low RPM behaviour is one of the reasons that I got rid of my 1125 (and my RC8)......


The high rpm behaviour of the 1125 is why I'm selling my Harley-engined Buells :roll:


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PostPosted: 21 Apr 2015 21:53 
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Current ride: S1W,S2T,1125CR
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Low RPM fuelling on the EBR1190s is excellent :sad1:

Steve

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PostPosted: 22 Apr 2015 20:58 
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Joined: 06 May 2009 21:29
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My speed triple has the sweetest fueling I've ever come across, it'll accelerate hard from nothing to flat out as smooth as you like, will trickle about in traffic as smooth as its possible to be, its lovely, I recommend trying one of these.

My Multistrada when I got it and stock was really smooth, super easy to ride at any speed and in any mode, I fitted a Tergi and the race ecu and its now a fire breathing beast in sport mode but fuelled well and smooth but completely different than it was before, I'd recommend this as well, if I only had one bike it would have to be this one.
Its basically an 1199 engine which is mapped differently to give slightly less top end and more bottom to mid range.
I imagine there are people out there who can do anything at mapping.

Andy


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PostPosted: 24 Apr 2015 08:57 
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Joined: 07 May 2009 21:25
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Current ride: CZ 350!
Location: Notts
No modern road going bikes with cat's are tuned for performance. They have to be tuned for best emissions and best performance of the catalyst which is a hot lean burn. this tends to mean the fewer cylinders a bike has, the snatchier it's low down running can appear to be. So they would all run better with a tad more fuel. No doubt some of the latest ECU's will be incorporating strategies to overcome some of these issues.

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PostPosted: 24 Apr 2015 16:07 
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DrBuella wrote:
and best performance of the catalyst which is a hot lean burn.


Catalyzer work best if mixture is constantly fluctuating between rich and lean (lambda 1.02 - 0.98), such all catalyzed vehicles are set up to run stoich (in average).

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PostPosted: 24 Apr 2015 20:23 
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gunter wrote:
DrBuella wrote:
and best performance of the catalyst which is a hot lean burn.


Catalyzer work best if mixture is constantly fluctuating between rich and lean (lambda 1.02 - 0.98), such all catalyzed vehicles are set up to run stoich (in average).



I knew that- I was trying to keep it simple lOl

I believe I am right in saying that the average achieved (lambda 1.0) is not the best for max.power.

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PostPosted: 24 Apr 2015 20:30 
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proff. patpending
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Location: Bristol - Gateway to all things good
Rule of thumb:

Stoich +10% fuel = best power
Stoich -10% fuel = best economy

Although modern engines runs at stoichiometric for emissions, they only do this at part throttle. Wide open throttle uses AFR for best power.

Responsiveness can be optimised by acceleration enrichment. Stability can be optimised by ignition timing.

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PostPosted: 24 Apr 2015 20:51 
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sounds like witchcraft to me wb ;)

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