R1100/1150GS Injector upgrade from the US - group buy interest?

Paul Young said:
I should get chance to fit them this morning and hope to get the bike down to the local shop for an mot so I'll try to update with first impressions, later. What's the guidance on resetting the moronic or not?

I'll also highlight that I have a PC3, 1100S inlet tubes, a K&N air filter and a 3.5bar fuel pressure regulator fitted, so it's already a bit 'interesting' and may not be very typical :green gri
Click to expand...

Paul,
Any info on that 3.5bar fuel pressure regulator please?


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From a k-series - 1200 IIRC

It was discussed on here some years ago so try a search. If there's no luck, I'll look back later and see what I can do to help, but I need to go out and I'm getting a 'look' from the Mrs...;)
 
Ive not read up on it but I would think that the ECU fuel map (including john's chipped revision to the map) are calibrated to keep a suitable AFR. The injectors as far as i know do not have variable flow rates, they simply open for the time specified in the map to deliver the requested inject quantity. I would think this is calibrated to work with the standard fuel pressure supplied by the stock fuel pressure regulator. Supplying a higher pressure by installing a higher rated FPR I think would cause a too rich mixture as theres no way of supplying the extra air needed, like you could achieve with a turbo in cars. The PC3 and inlet tubes on Pauls bike might mean he can adjust to get the correct AFR even with the higher pressure, but I doubt it would work with a standard bike.

I could be completely wrong though.
 
It works by just putting the same required/measured amount of fuel in, but under higher pressure so it generates a snappier throttle response.
 
gog said:
Ive not read up on it but I would think that the ECU fuel map (including john's chipped revision to the map) are calibrated to keep a suitable AFR. The injectors as far as i know do not have variable flow rates, they simply open for the time specified in the map to deliver the requested inject quantity. I would think this is calibrated to work with the standard fuel pressure supplied by the stock fuel pressure regulator. Supplying a higher pressure by installing a higher rated FPR I think would cause a too rich mixture as theres no way of supplying the extra air needed, like you could achieve with a turbo in cars. The PC3 and inlet tubes on Pauls bike might mean he can adjust to get the correct AFR even with the higher pressure, but I doubt it would work with a standard bike.

I could be completely wrong though.
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Guys, I experimented with this extensively. Higher fuel pressure doesn't really make any difference except for a few tanks of fuel. If you have a connected O2 sensor, the Motronic eventually slightly shortens all the fuel pulses to correct. Read: http://advrider.com/index.php?threa...-af-xied-for-bmw.749080/page-40#post-23675190.

Your new injectors turn on faster. For a while you will get a little more fuel but then the Motronic will slightly shorten the pulses.

If you want to get a little more fuel forever, get an af-XIED. It will work very well in tandem with your new injectors.
 
thanks Roger. what would be the effects of the increased fuel pressure on an 1100 with no o2 sensor, open loop with co-pot?

i assume simply richer mixture. the fuelling is already richer on my bike due to johns chip.
 
gog said:
thanks Roger. what would be the effects of the increased fuel pressure on an 1100 with no o2 sensor, open loop with co-pot?

i assume simply richer mixture. the fuelling is already richer on my bike due to johns chip.
Click to expand...

With no O2 sensor, the effect is to richen the mixture. A 3 bar regulator is about 44 psi, a 3.5 bar is about 51 psi or 17% higher pressure. That means that you get about 8% more fuel everywhere.

Those with no O2 sensor should remember that the R1100 and R1150 have fuel tables that were designed with non-ethanol fuel in mind. For the many of us who now run fuel with 10% ethanol, a bike with no O2 sensor runs 4% leaner than designed. Therefore, a 3.5 bar regulator is a good addition to a non-O2 bike. (O2 sensor bikes don't have the problem because the O2 sensor and Motronic work together to richen out the effect of E10 fuel.)
 
makes sense to me. here in the UK we are mostly E5 but set to have E10 slowly introduced until it's the norm like it is in the US.
 
If you want to get a little more fuel forever, get an af-XIED. It will work very well in tandem with your new injectors.[/QUOTE]

This will be my setup, as I already have the af-XIED fitted :D
I just need to find time around work to fit them :blast
 
I'll be first then but please bear in mind that I have limited time on my hands at the moment so this is just a 'first impression' report..
10 minutes to fit and then a 10 mile round trip to Tesco to collect some lamb chops, scallops and Prosecco for a bbq / wake :comfort
They're grrreat :thumb

Thinking about adding one of those axiedhtjuregr type unpronounceable things at some point :cool:
 
i fitted mine today. took 20 mins and the hardest part was figuring out how the bits fit together

immediately i notice it starts quicker, after just two rotations from cold rather than 4/5 usually. idle is nice and smooth but it was before, so no noticeable difference there for me.

where i find the best improvement is the smoothness and throttle response. it feels much more linear low down and a definite feeling of more power in the midrange.

i only had a 15 min ride home and no fast roads but so far i am impressed and feel it was money well spent. it just feels 'rejuvenated' for lack of a better word.
 
Fitted mine yesterday as well, didn't really want to as such as the bikes still not running 100% but I wanted to se if the issue was a blocked injector.
My original issue (vibration) is still present but greatly reduced. Engine picks up better and tickover is more even....not night and day but noticeable....however surging is greatly reduced so that's good.
Definatly has spruced the old clunker up a bit so on that score I'm happy with the results.
 
oh dear

Fitted mine yesterday and went out for 50 miles ......had very poor fuelling like a big hesitation between 2000 and 3500 revs ....... riding at a steady 40 it slows slightly
and then hesitates ..took them off and put my standard ones back and all is well in my world again ......... any ideas what the problem may be ? .........do I need a higher pressure regulator ?
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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