Airflow Research Cylinder Heads
The Test
A 355 ci test mule shortblock with GM Vortec heads making around 10.1:1 compression was swapped for AFR's 195 Eliminator Street heads. The new lungs paired with a Thumpr' cam dramatically improved air flow which is where the dramatic increase in power came from.
Before
Max power: 396 @ 5,900
Max torque: 418 lb-ft @ 4,200
Average power: hp
Average torque: lb-ft
After
Max power: 453 hp @ 6,200
Max torque: 435 lb-ft @ 4,300
Average power: hp
Average torque: lb-ft
Difference: +57 hp; +17 lb-ft
AFR
661.257.8124
airflowresearch.com
Comp Cams Hydraulic Roller XR294 (Nitrous Grind) 242/248, 540/562 With 110 Lobe Separation
The Test
We swapped out nitrous cams for a more aggressive 'stick from Comp. The new cam entered the 400ci Dart short-block with Dart 215 Pro 1 heads, a Dart single-plane manifold, and a Holley 830-cfm carburetor on top. During the run, a 125 shot of nitrous was sprayed on Westech's engine dyno.
Before
Max power: 624 hp @ 5,500
Max torque: 630 lb-ft @ 5,100
Average power: 416 hp
Average torque: 500 lb-ft
After
Max power: 702 hp @ 5,900
Max torque: 684 lb-ft @ 5,200
Average power: 467 hp
Average torque: 529 lb-ft
Difference: +78 hp; +54 lb-ft
Comp Cams
901.795.2400
compcams.com
Hooker Super Comp 2-Inch Headers With 18-Inch Collectors
The Test
Most often, a larger set of headers will increase flow and scavenge the exhaust more efficiently. The 540ci 10.5:1 big-block tested went from 13/4-inch headers with an 18-inch collector to a 2-inch Hooker Super Comp header with the same 18-inch collector. With a more "open" exhaust, power increased.
Before
Max power: 667 hp @ 5,900
Max torque: 686 lb-ft @ 4,400
Average power: 564 hp
Average torque: 628 lb-ft
After
Max power: 702 hp @ 6,000
Max torque: 696 lb-ft @ 4,700
Average power: 574 hp
Average torque: 642 lb-ft
Difference: +35 hp; + 10 lb-ft
Hooker Headers
270.782.2900
holley.com