[zl1vette]

Ahh, nothing like some good old fashioned research from back in the day. Here are a couple of tests on a ZL1 Camaro:

A guy from Kansas City (Dick Harrell, you may have heard of him) tested a 1969 ZL1 Camaro for the May 1969 issue of Super Stock and Drag Illustrated. The exhaust manifolds were swapped for a set of headers, but still ran the full exhaust. Back pressure being what it is, the headers probably offered only minimal advantage. The car was fitted with a set of street legal 8.00/8.50 x 14 M&H 6 ½” Super Stock tires. With the newer compounds in the repro tires of today, my estimation is that these are probably very close in traction to each other. The Camaro ran the stock Turbo Hydra-Matic transmission with a stock rear end housing a set of factory 4.10 gears. The 850 cfm double pumper was swapped for an 850 cfm with vacuum secondaries because the tires could not hook up.

Dick Harrell ran a 1/4 mile of 11.85 seconds @ 119.06 mph. Uncapping the headers yielded 11.64 @ 122.15 mph.

The guys from Popular Hot Rodding showed up later, and for their July 1969 issue, Dick Harrell, running the same configuration, but with different jets in the carburetor and timing at 42 degrees advance, ran a quarter mile of 12.14 seconds @ 117.80 mph.

There was no mention of track conditions or temperature, but having spent almost a year at wonderful FT. Lost-in-the-woods, MO, I can tell you that there is a HUGE temperature difference between FREEZING COLD Feb and NICE WARM Apr. Since most magazines in 1969 were written three months prior to publication date, I am estimating that these are approximately the actual test months and could easily account for the 0.29 second difference in the two cars with closed headers.

And of course we all know that Chevy built the Corvette to perform better than the Camaro, even with the same motor, so one would expect even better times from a ZL1 Vette.

To COPO Pete and JJ, I say that the above referenced articles should more than prove that your numbers and cars are legit. Not that you don't know the truth; this was merely for the nay-sayers.

BTW, according to "Corvette Quarterly", Fall 1988, the official publication from some car company (Chevrolet, you may have heard of them), the ZL1 motor idles at 2000 RPM, and runs rough below this point. As far as vacuum is concerned, a Competition Cams XR300HR-10 (close to L88 specs) .562/.580 I/E lift and 300/306 duration @ 0.006" can only pull 6.5" Hg @ 1000 RPM.

Seems reminiscent of when the Corvettes were banned for dominating every Showroom Stock race they entered until they had to form the Corvette Challenge series just to race.