919T Installation Manual (Updated March 14, 2009)

This is an abbreviated version of the 919T Installation Manual. This provides a good example of the complete manual, though - good descriptions, lots of detailed information and pictures.

919 Stock Left Muffler Modifications

This shows what steps are need to modify the stock left 919 muffler so it will flow the amount of exhaust needed for the 919T.

919T 10mm Head Stud Installation

This shows the steps needed to upgrade to ARP 10mm Head Studs

Injector Sizing Spreadsheet

We build turbo systems, and we needed a way to figure the optimum size for the fuel injector that we needed. So, we developed this handy spreadsheet. You plug in the info you have in the yellow cells:

1. Engine Size in Cubic Inches (Worksheet included below for liter engines)
2. Number of Cylinders
3. Injector Size (Lbs/hr), but will tell you CC/Min
4. Boost in PSI (Naturally aspirated engine just put 0)
5. Number Of Valves Per Cylinders (2 or 4)

The spreadsheet assumes that there's unlimited airflow for easy computation.

On the 919, the injectors flow about 21 lb/hr and at 7 psi boost, notice that the injectors are at 91% duty cycle at 9500 RPM, so they're open most of the time. 90% is about max for an injector, so that's about the right size injector for 7 psi boost. Also note that at 9 psi, the injectors are 100% duty cycle (open all of the time). This shows that the injectors will support more boost at lower revs, but won't flow the amount of fuel needed at 9500 rpm though. That's the main reason that boost for the 919T system is limited to 7 psi.

Interesting info - most people think that the injector just gives a good spray of fuel at wide open throttle, but actually the injector is open and spraying fuel most of the time, and the air/fuel mixture is just sitting in the intake port waiting for the intake valve to open and let the air/fuel mixture into the cylinder. The intake valve is only open about 30% of the time, while the injector is spraying 90% of the time!

Feel free to use this all you want, but please leave the WAVE info in there. After all, we did all of the work, please just give us credit for it.

Thanks.

Sound Bite - Interstate 25

Sitting on the shoulder of the interstate, our rider took off up to 100 mph. Our bike is geared with a smaller rear sprocket for highway riding, so it doesn't get a very good launch.

Sound Bite - Four Lane Local Road

This was recorded on a 4-lane road here in Colorado Springs. This road has a 45 mph limit, so our rider couldn't really get the bike going too fast. Second gear, 1,500 RPM, he just held the gas wide open up to 80 mph. This gives you a good idea the different sounds that the bike makes when it's under boost.