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
Have a read through the thread in the rc390 forum here: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.
The "before" was Competition Werkes shorty exhaust, TYGA Performance header, open lid airbox with inverted K&N filter, and Chad Wells tune.So you had full exhaust, PC, filter, tune and it made 42?
You added the air box and injector and it made 47?
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."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."
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!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.