The Ultimate Street Car Challenge 3: The Dyno

Horsepower and power delivery are up for grabs on the dyno. That's two contests, or 14 percent of the total score at stake. Based on the tension in the dyno room, you'd think this was the whole contest. K&N's spotless R&D center houses three Dynojets, an all-wheel-drive model, a conventional two-wheel-drive 248C and a motorcycle dyno. We only used two of them.

The dyno, more than any part of this test, is where the bragging rights are. Everyone came looking for the big number, but most were hoping, at best, for second place. You can't see the Viper driving through the parking lot, preceeded by a cloud of debris blown up by the supercharger's gale-force bypass valve, and not expect it to pound your sissy little car into the ground.

No surprise, then, the Viper dominated on the dyno with 842 hp at the wheels. That's enough to leave two burn marks on the floor from the side exit exhausts. That's enough to leave a mysterious coating of ash on everything in the dyno room. That's enough to make all the smart people leave the dyno room before each run. And that's still not as much as the car usually makes. Normally, Paolo runs without cats, but all 842 hp were being strained through ceramic grids of precious metals in anticipation of the emissions test not 10 minutes later. That ash was probably pulverized catalyst.

Both Rich Eager's red '94 Supra and Nick Wong's Skyline cleverly avoided the catalytic compromise by diverting exhaust through cutouts on the dyno (with a manual block-off plate on the Skyline and an electrically actuated valve on the Supra). Each delivered more than 600 hp from less than half of the Viper's displacement.

Roy Narvaez was actually disappointed with his 545-hp pull. Two hundred seventy two hp per liter--and he was disappointed! Apparently, he had made more than 700 hp a few days earlier at XS Engineering. K&N's dyno has two heavy rollers, which makes for a fairly long pull compared to the quick sweep through the powerband on the Dynamic Test Systems dyno at XS. Roy's turbo was trying so hard to jam boost down the Eclipse's throat through the mid-range that the air kept stalling and pushing back through the compressor. This audible compressor surge doesn't happen on the dragstrip or XS's dyno, where the engine accelerates out from under the problem.

Matt Andrews didn't expect big things from his '97 Supra. He was, after all, running a stock engine with stock turbos and only the basic bolt-on performance upgrades. Four hundred fourty nine hp at the wheels, it turns out, is the most anyone has ever recorded with these mods. At least the most anybody in the room knew about. Hey, it was enough to make him really happy.

Jay Esterer was suffering from cams that were ground with the wrong lobe centers, making the car refuse to idle and screwing with the powerband. The ill BMW V12 still managed 409 hp at the wheels. Not bad for the only naturally aspirated car here.

While everyone focused on peak power, it was the power delivery score that delivered the most surprises. Power delivery is, effectively, a simple measurement of the area under the torque curve. By simply adding up the torque values every 100 rpm throughout the powerband, we were able to derive a simple number to reflect the flexibility of an engine's power delivery. Here's the thing, though: where's the powerband? We figured each car had better be making useful torque by the time it's 40 percent to redline, so that's where the calculation starts.

Look at the power and power delivery scores and you'll see that only three cars scored in the same place on both dyno contests. The Skyline and Eager's red Supra swapped positions because, despite the Supra spooling up slightly sooner, the Skyline could keep revving for 1500 rpm longer. That means a longer powerband and more flexibility between corners. Revs paid off for Troy Truglio's MR2 as well. Despite a nasty high-rpm misfire, pulling all the way to 9800 rpm gave him lots of data points to add up. The biggest success story on the power delivery scoresheet, though, was Jay Esterer's Ultima. Despite scoring eighth on power, his broad, naturally aspirated powerband scored him fifth on power delivery. --Dave Coleman

OVERALL
In all, this year's dyno performance was staggering. The average peak power was 518 hp. One would expect the Viper to leave the dyno cell in the lead, but it was not to be. Thanks to a last-place finish in the base-price scoring, dominating the dyno still only put the Viper in second. The Skyline still held the lead. Barely. Thanks to that healthy power delivery score, Esterer's Ultima held on to third place in spite of his seventh-place power score. OK, enough chest pounding. Time for the emissions test.

Car Show Test	The Guru Panel Test	Dyno Test
Emissions Test	Grandma Test	Driveability Test
Fuel Economy Test	Skidpad Test	Road Course Test
Acceleration Test	Braking Test	Gross Display of Horsepower Test
	The Winner

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