It was becoming an everyday thing at VETTE "Command Central." One of the phones would ring, we'd answer it, and someone would say something like: "Hey! Am I going to get to see what happened to the C5 bolt-on story before I get too old to remember why I wanted to see it in the first place?" And there were stacks of e-mails to the same effect.
Well, West Coast Corvette's C5 is back, sorted out and running strong, and as promised, we have both final dyno and drag strip test results (from two different sessions, to boot). First, let's look at how the '98 coupe did on the dyno.
We headed over to Harv's Performance Center in Whittier, California, and strapped it down to "Big Harv's" Dynojet 248C chassis dynamometer. We were rewarded with a maximum of 367.2 horses at 5,800 rpm and 368.5 lb-ft of torque at 4,500 rpm. Remember, these are "at the wheels" readings. As a general rule, there's roughly a 15 percent power loss due to driveline friction in a manual transmission car, so we divided the horsepower and torque figures by 0.85, which indicates the Stage 4 LS1 was actually making 432 hp and a stump-pulling 433.5 lb-ft of torque.
With dyno testing out of the way, it was time to hit the quarter-mile. Our first outing was the Street Legal Drags at Pomona. Shod with a pair of 315/35R17 BFG Drag Radials (almost exactly the same diameter as a stock C5's rear tires, with a wider footprint), WCC's Vette recorded a traction-limited best run at 12.76 ET at 110 mph. A few days later, at Los Angeles County Raceway in Palmdale, we ran a second test session. After switching to a pair of 26 x 11.5-16 Mickey Thompson ET Street tires (essentially DOT-legal drag slicks), the silver C5 gained three tenths, pounding out a 12.478 at 112.444 mph, with a respectable 1.851 60-foot time.
With some practice-or a more experienced driver for the drag tests-the Stage 4 C5 could potentially get into the 12-ohs or 12-teen without much difficulty.
Regardless, 12.40's are nothing to sneeze at. It's a solid second quicker than a stock C5 would run under the same circumstances-and proof that this package of performance upgrades works! Now it's time to go Viper hunting.