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I met Frank, owner of Advanced Performance, summer of 00' through a buddy of mine. I had just bought a 72 Pro Street Duster
, and was told when I bought the car it ran low 11's with the mufflers on. I was excited because I wanted to buy a 10 second car ready to go. So I ran out to Rock Falls, and barely got into the 11's.
I was pretty dissapointed to say the least. Frank suggested either porting my 906's or getting Mopar Stage VI aluminum heads, and porting them. He explained he could guarantee at least a 5mph
gain with the Stage VI heads, no matter how much work was done to the 906's. I wasn't convinced at first, but after some reasoning, I ordered the Stage VI's. Frank performed a full race port
job on the new heads, which flowed over 300 cfm when completed. We bolted them on, and went racing. Here's the before and after numbers:
Before (906 heads) - Best of 11.49 @ 118mph. 7000rpm through traps. After (Stage VI heads - no other changes) - 11.18 @ 124mph. 7400rpm through traps. And, the car stumbled the
first 60 feet (we believe the change in intake velocity had an impact, more on that later). Why? Because air flow matters! Yes, It's true. I/we (Advanced Performance) proved it.
And, there exists a mathmatical equation that proves this. Depending on the motor configuration (cam duration, compression, ect.), a horsepower increase in excess of 2hp per CFM can be gained!
Exciting stuff. And, a reality. Here's the guts: The piston goes down, air gets sucked in. Air is picky - and likes to follow a certain path. What path? That's where the
research and development pays off, and, owning a "Super Flow 600" provides the mean for that development. No, this isn't an advertisement for "Super Flow 600". It just happens to be the
best flow bench available... Volumetric Efficiency 101: Lets say you have a milk carton. It's empty (because we like milk). When empty, sitting there without the cap on, there's a
certain amount of air in it. If you were to measure the space in the jug, you would have identified 100% percent of its capacity. If you were to blow into it, like what a supercharger does, you
would increase the total volume of air in the jug. Hence, +100% of it's capacity. Volumetric efficiency as it pertains to internal combustion engine performance, is the total amount of air/fuel
in the cylinder at the moment the motor begins it's combustion stroke (all valves closed). A good number is in the 95%+ range. Frank is consistently achieving better than 100% Volumetric
Efficiency in his porting work. Yes, it's like getting a free supercharger. Back to my experience. Frank had guaranteed me at least 5mph gain, I got 6. And, there's more there yet.
The car stumbled terribly off the line (1.7 - 1.9sec 60 foots), likely because of the stall converter. The car has a .650 lift 290 degree at .050 solid lifter cam, and we increased the intake runner
size by nearly .500 in. The converter stalls at 3600rpm, way too low to get the motor up to working rpm's. The installed cam's working range is from 4000 to 7000. To resolve that we are
installing a 5000rpm 8" Dynamic stall converter. Also, lower 4.30 gears are in order. The old 4.88's are way too high (remember going through the traps at 7400rpm's? I do ;}).
Frank has decided to sponsor the 72 Duster for 01'. We'll see you at the races! P.S. Thanks to Frank for all the hard work in 00'! Back to AP Bits |
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