Thread: porting
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Old 08-01-2012, 08:13 AM   #30
Strong Bad
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Joined: Oct 2007
Location: Santa Susana, CA
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Hubristic theory is one thing, horsepower to the ground and being able to manipulate the power band where you want it is a completely different matter. NONE of the greatest 2 stroke motocross tuners of the 70's had anything more than a high school diploma. Back in the day, we not only gave riders more horsepower, we gave them horse power their riding ability could use. Donnie Emler's FMF had a great advantage in his first shop with the dirt road and lot next to the shop. He learned how to develop real world horsepower that would win on the track, not set speed records on Bonneville Salt Flats. Back in the 70's the speed shops who did well were the ones that realized that not all of their customers could used mega HP with a very narrow powerband the pros could ride. Their services matched both the pipe and the porting to the rider's ability.

Hard to lower the exhaust port bringing the powerband down into a lower rpm. The Power Valve that came in the 80's did exactly that, it allowed for a variable exhaust port timing. Increasing bottom end is easier done with a longer headpipe and/or center section with the pipe. Increasing the volume in your intake is what killed your torque.
"I couldn't wait for success, so I went ahead without it."
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