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Old 11-01-2002, 10:59 PM   #26
jim_howard_pdx
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Join Date: Apr 2002
Location: Portland Oregon
Posts: 247
Cool

I bet if you retarded the cam 4 to 6 degrees, you would be into the 9's. The biggest mistake racers make in engine building, is to think the race is won off the launch.

Everyone thinks that and the magazines say you 60 ft times and first 330 ft make or break a race. They may be right, but primarily for dragsters and pro stock cars that are running within tenths of a second from one another.

Our engines were built for top end power production. From 660 ft on is where a race is really won or lost. We used to do tricks, like run our final gear underdriven. So instead of a 1 to 1 final gear, we would run a 1.06 to 1 gear. That way the engine was always pulling against a mechanical advantage.

When you retard the cam, you rarely lose significant torque off the line, because typically you are launching at 4 to 5,000 RPM. But the extra power up top is really significant to getting into the 9's.

Another thing we learned is that short shifting first and second gears to get into third gear faster ended up cutting our times from 9.6 to 9.2. So we were shifting at 5500 RPM in first and second, and 7500 rpm in third. That was with a Jerico 4 speed. We changed to a C6 and then a Powerglide to get even more consistency. Running an automatic with a line lock and trans brake allowed us super repeatable 60 ft times. More importantly, it allowed us to vary rpm launch to correct for track temperature and traction conditions and still run our index. Even with a two speed or three speed slush box, we were still shifting from first to second at 5500 rpms. (we had a 5500 rpm stall converter).

Kevin's Nova friend may have a fast car, but just how many trophies did he pick up. We ran three years and lost just two races when we made the finals. That is alot of trophies, and enough money to almost pay for the car--but not for our time.....
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