I used the table / guide to figure what size injectors I would need for my motorcycle based on horsepower. However, this motor is a long stroke very torquey motor: V-twin, 92mm bore X 98mm stroke, 680cc per cylinder, 62hp and 84ftlbs at the rear wheel. It has been my experience that torque producing engines are less fuel efficient than engines with the same displacement but that are tuned for hp. Truck engines, inboard boat engines etc. really drink fuel.
My calculations suggest a 19lb injector which is good news since they are so common. Should I consider the torque factor or just go with the 19lb'ers?
Injector selection.
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Go by HP.
By the way, trucks and boats get less mileage because they a a)heavier b)under constant load c) both.
HP is a measurement of keeping torque effective at higher rpm. Peak torque comes in at a particular rpm and peak horsepower usually higher in rpm. The broader the range of the engine the more all around use you can get out of it. A racing engine designed for ultimate power will have the torque and HP peaks closer and further to the right on a dyno curve, and generally require the engine to be spinning a shallower/smaller diameter prop/stiffer set of rear gears to keep the engine revving for a given speed.
Put a truck engine in a car and it will get better mileage.
Put a car engine in an SUV and it will get worse mileage than when in a car.
Read paragraph 2 again....
By the way, trucks and boats get less mileage because they a a)heavier b)under constant load c) both.
HP is a measurement of keeping torque effective at higher rpm. Peak torque comes in at a particular rpm and peak horsepower usually higher in rpm. The broader the range of the engine the more all around use you can get out of it. A racing engine designed for ultimate power will have the torque and HP peaks closer and further to the right on a dyno curve, and generally require the engine to be spinning a shallower/smaller diameter prop/stiffer set of rear gears to keep the engine revving for a given speed.
Put a truck engine in a car and it will get better mileage.
Put a car engine in an SUV and it will get worse mileage than when in a car.
Read paragraph 2 again....
The throttle bodies I got for this bike are from a BMW 1100cc twin. They are 45mm and have an injector mounted in them. The Bosch number says its a 28lb/hr injector. Since going too large on an injector mostly causes problems at idle and this bike is only an 1100cc engine versus my 1360, is it safe to ASSume that my bike will handle these injectors at idle since a much smaller engine does? I'm sure my engine makes more power initially and at lower rpms than does the RT1100 that these bodies came off of.