Steve in Seattle
08-06-2006, 05:29 PM
Interesting article on NHRA Top Fuel and Funny Car blower belts.
http://www.gates.com/brochure.cfm?brochure=5051&location_id=557
When the belt is installed and aligned on the crankshaft–blower drive, there is a margin of error of 1/4° ... But the biggest “belt-eater” ... results from “pedaling.”
This normally occurs within 300 feet from the starting line, when the drive feels the rear tires begin to slip and they smoke up the track. The engine crankshaft is accelerating from 9,000 to 11,000 rpm, and then when the driver lets up on the gas, it slows to 2,000 rpm.
At the same time, the blower is accelerating and building up inertia. The engine and the blower are working against each other, and the belt breaks from the force of stress and the two opposing speeds.
Not sure if this qualifies as Advanced "Tech", but it's interesting and didn't really fit in other forum. :)
One more: http://www.gates.com/brochure.cfm?brochure=932&location_id=548
Interesting stuff when you consider that belt is used to drive a 60+psi blower that eats up HUNDREDS of ponies on a 7000+ hp engine.
The crankshaft numbers quoted in the article must be old however... I was under the impression that NHRA now limits the fuelers to 8400rpms via a MSD ignition.
http://www.gates.com/brochure.cfm?brochure=5051&location_id=557
When the belt is installed and aligned on the crankshaft–blower drive, there is a margin of error of 1/4° ... But the biggest “belt-eater” ... results from “pedaling.”
This normally occurs within 300 feet from the starting line, when the drive feels the rear tires begin to slip and they smoke up the track. The engine crankshaft is accelerating from 9,000 to 11,000 rpm, and then when the driver lets up on the gas, it slows to 2,000 rpm.
At the same time, the blower is accelerating and building up inertia. The engine and the blower are working against each other, and the belt breaks from the force of stress and the two opposing speeds.
Not sure if this qualifies as Advanced "Tech", but it's interesting and didn't really fit in other forum. :)
One more: http://www.gates.com/brochure.cfm?brochure=932&location_id=548
Interesting stuff when you consider that belt is used to drive a 60+psi blower that eats up HUNDREDS of ponies on a 7000+ hp engine.
The crankshaft numbers quoted in the article must be old however... I was under the impression that NHRA now limits the fuelers to 8400rpms via a MSD ignition.