Thursday, January 19, 2012

Why is my performance so bad?

I have a yamaha vstar 650, I have vance and hines short shots and a K%26amp;N air filter. I also cut some holes in my airbox to increase airflow. I had my bike carbs rejetted and Dynoed today and peak horsepower was 30 and torque was 35. I was extremely dissatisfied. That is lower than what the vstar 650 is supposed to get stockWhy is my performance so bad?
If by stock you mean the factory claimed horsepower, that's usually measured at the engine crankshaft and most dynos take measurements at the rear wheel. The former is always going to be higher than the latter.Why is my performance so bad?
You should have saved your money to be honest with you.Everyone who has owned a 600 series bike of any other brand-then bought the v-star because of it's sharp profile has complained of the same exact thing as you.I had an 1100 custom classic and when my friend rode it he said it was a little to much for him so he bought the 650.Three weeks later he was poopin his pants when he went to pass a truck and there was almost nothin left in the power and he almost got killed.He ran the gambit of things such as you and could not squeeze one more drop of power from it.Believe me your bike is no different than any of the other 650's! Sadly it is the nature of that particular beast.Why is my performance so bad?
You are learning what many mechanics have known for years. To get more power out of those aftermarket exhaust and intake modifications you also need a set of cams that are matched for the decrease in Back pressure. And the change in intake characteristics can significantly lower low rpm power. In your case you have lost 6 hp and you paid money to do it. Since the 650cc v-star is designed for maximum torque at 3,000 rpm instead of 8,000 plus for most sportbikes your mods will reduce power while increasing fuel consumption. Stock is always better for fuel economy.

No comments:

Post a Comment