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Discussion Starter #1 (Edited)
I'll post more details in my build thread but took the bike to the dyno today. With just the switch to modified airbox and larger injector, picked up over 5hp
 

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Discussion Starter #2
Supporting mods are Dynojet Power Commander, The Mariner 3D open airbox lid with inverted K&N filter, Gray Area KTM custom airbox , larger fuel injector, Tyga header and Competition Werkes exhaust.

Gains on the dyno today were from just the airbox and injector !

There is a small loss in low end torque and hp but it picks back up again and climbs much harder up top. Base run was with Chad Wells map for Akra flashed ECU, open lid and exhaust.
 

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Well that's good news, but IMO the bigger injector is not what gave the HP gain. I don't think that stock injector is so tiny to give all the extra fuel that is needed for an exhaust - air filter mod. A turbo conversion, yeah probably will need larger injector. Maybe the pc wasn't properly tuned or you god very lucky with the size of the new injector while the pc still needs better tuning.
 

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Discussion Starter #5 (Edited)
Well that's good news, but IMO the bigger injector is not what gave the HP gain. I don't think that stock injector is so tiny to give all the extra fuel that is needed for an exhaust - air filter mod. A turbo conversion, yeah probably will need larger injector. Maybe the pc wasn't properly tuned or you god very lucky with the size of the new injector while the pc still needs better tuning.
Have a read through the thread in the rc390 forum here:

https://r.tapatalk.com/shareLink?url=https://www.rc390-forum.com/forum/showthread.php?t=2837&share_tid=2837&share_fid=157361&share_type=t

It's needed to continue making power at the higher the rpms.

"Its needed in the mid and on top. With the increased rev limit to 11250 the duty cycle of the injector is no longer sufficent to provide the motor adequate fueling from about 6500 RPM and up."
 
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Discussion Starter #6
So you had full exhaust, PC, filter, tune and it made 42?

You added the air box and injector and it made 47?
The "before" was Competition Werkes shorty exhaust, TYGA Performance header, open lid airbox with inverted K&N filter, and Chad Wells tune.

For the "after", we swapped out the airbox with the modified intake runner and the injector.

There is a drop in max torque and power down low, not sure if I can tune that out later... We ran out of time basically at the end.
 

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"Its needed in the mid and on top. With the increased rev limit to 11250 the duty cycle of the injector is no longer sufficent to provide the motor adequate fueling from about 6500 RPM and up."
so this means that they try the stock injector at 95% and the mixture was lean; that's really hard to believe, except if the piggy back (pc) fails to interfere effectively stock injector. With a remap, stock injector wouldn't be a problem. Or the stock injector is so small and they are right.

I am not trying to say that they tricked you , just trying to give you a positive doubt to those they are telling you so you can get the best service from them. Usually stock injectors are sufficient for up to 30% more power and that's happened in order to manage extreme cold conditions, etc. But this is a general rule, maybe Ktm has other opinion.
 

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Discussion Starter #8
The airbox and injector are sold separately. There's no obligation to buy the injector.

However, I had faith in the testing that was done which proved the larger injector was needed, particularly at the higher rpms.

The intake runner is based on the homologated part available on the RC390R. It drastically alters the flow characteristics.

Keep in mind I'm running with open lid airbox and inverted filter already.

I've also got the Akra flash on my ECU. As a result, we ended up leaning out the base map I got from Gray Area KTM quite a bit in the lower RPM ranges.
 
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The airbox and injector are sold separately. There's no obligation to buy the injector.

However, I had faith in the testing that was done which proved the larger injector was needed, particularly at the higher rpms.

The intake runner is based on the homologated part available on the RC390R. It drastically alters the flow characteristics.

Keep in mind I'm running with open lid airbox and inverted filter already.

I've also got the Akra flash on my ECU. As a result, we ended up leaning out the base map I got from Gray Area KTM quite a bit in the lower RPM ranges.
That's the spirit! Having a skeptical thinking and examining. Enjoy your rides! I saw pictures of that tyga header, and it really looks bigger than stock! Surely needs more fuel!

Στάλθηκε από το ASUS_X00HD μου χρησιμοποιώντας Tapatalk
 

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Discussion Starter #10
Adding pics back




 

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Discussion Starter #11
Different day, different dyno. Local motorcycle shop 613 Motorsports had a 10 Year Anniversary Party complete with onsite dyno. 3 pulls for $60 with proceeds to local charity. Highest and lowest HP competition. They had a 400cc and lower class so entered the Duke. When I arrived, highest HP was 2017 RC390 with Rapidbike Evo and Yoshimura exhaust -> 42.xx HP. I was closer to end of day and ended up with 45.42HP for highest in category. Lowest 400cc bike was vintage Honda CB400 at 28hp.

I had scaled back rev limit to 10500 after tuning was complete. I think I will put back to 11000 as it seems to get to 10500 very quickly with no signs of power dropping off...
 

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Nice CDN Duke, congrats,

Please let us know what, if any, modifications you have done to your Duke engine wise.
 

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Discussion Starter #13
Check my build thread for details.

Nothing internal. Inverted filter and open airbox. Tyga header, Competition Werkes pipe. PCV with custom map. Gray Area KTM intake runner and injector.
 
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