Oversized Fuel Injector

kostean

Member
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There is no other difference rather than the flow rate. The oversized injector does not give any performance advantage in comparison with stock one without considerable engine modifications. If in case tuning both air intake to allow more flow as well as a performances exhaust system, then indeed, considering you have tuneable ECU there might be a situation where more fuel would be needed.
 

musti

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There is no other difference rather than the flow rate. The oversized injector does not give any performance advantage in comparison with stock one without considerable engine modifications. If in case tuning both air intake to allow more flow as well as a performances exhaust system, then indeed, considering you have tuneable ECU there might be a situation where more fuel would be needed.

I think this is spot on.

My current setup has a free flow intake and exhaust, just not a programmable ECU / piggy back. I am currently using a powertronics piggy back with provided maps. I cannot customize them without a dyno and I dont have easy access to it.

Thanks for sharing the feedback. I cleared out a lot of smoke.
 

picto

New Member
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The original injector doesn't posses enough of a "hole" to pass enough fuel to fit the requirements of that setup. A new injector with a bigger "hole" will allow your fuel system to meet the needs of the modifications you have installed. I have still yet to have a stock injector cc tested but we settled on the current size as it will suit the maximum amount of fuel needed for a full blown superbike on MR12. Most don't have this setup but some do so its easier to size down the injector with a tune then make it bigger!


the stock injector is rated to flow 186cc per min according to bosch.
 

KTMasean

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As it gets somewhat confusing I have tried to create an excel sheet for the first-Gen little Dukes from the info I was able to find on the internet. By no means this is complete or 100% correct so any input from people that KNOW is appreciated to complete the sheet.
 

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KTMasean

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An update on my research;
It seems that all the fuel pumps used from the 125 to the 390 are the same and put out 6 bar.
The main difference is the reducers valves regulating the line pressure to 2.7 bar (125/200 and 3.6 bar 250/390
Now I need to find out where to source these reduction/regulator valves.
KTM only sells the assembly so no joy here and no individual spare parts of the parts fiche.
If anyone knows, feel free to share on the forum.
 

Icehax

Member
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Ok, I have a question about this. Say i put the oversized injector on, for the closed loop i have a FuelX which i can set to be more lean or rich to my Likings, so that's set, as for the open loop (using powertronic) if I just calculate the ratio between the original injector flow rate and the oversize one then adjust the map by multiplying all the fueling values by that ratio, will i get a map that is virtually an exact copy of the one I'm currently using with the normal injector? Since from what I can understand all I'm changing is how long the injector sprays for
 

Pierre

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Hi,
I have a 2022 RC390 with full exhaust and DNA airbox lid and K&N air filter too. PT4 and Pro FuelX... I need more power still...
Can you recommend a fuel injector?
What others mods does work?

Thanks
Pierre
 
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