Drivetrain and accessories power/torque loss. - 06/13/18 02:43 PM
Just in case anyone is interested in such stuff.
I've heard 10% to 25%. My engine, with the smaller carb, made 490 HP and 551 lb/ft torque. That was with the fuel pump, water pump and open headers. I changed the camshaft from a 230/236 to a 236/245, that had a projected loss of 5 lb/ft torque and a gain of about 5 hp.
Last Saturday the club in Sidney had a dyno session at a shop in Victoria, 15 cars, two pulls each to get a base line for further tuning. To try to get a closer comparison, I removed the Q-850 and installed the 800 EPS, The car has manual fuel pump, water pump, power steering, oil cooler, tubular headers, 2-12" dual exhaust with flow through mufflers, twin 30 amp fans, a 140 amp alternator, manual transmission, steel drive shaft, 69 Slomaro c-clip posi rear, 255/60R15 tyres on 15 inch Torque Thrust II wheels, all taking there share of power.
The car made 389 HP and 428 lb/ft torque. I know it's not an exact comparison as I did not engine dyno with the new camshaft, but I'm positive the projected are within five units.. The chassis numbers are 79-80% of an engine dyno. I would have liked to engine dyno it with the new cam and the Q-850 but money ran out long ago.
Rather coincidental both the torque and power numbers are Pontiac engine sizes, 389 and 428!
I've heard 10% to 25%. My engine, with the smaller carb, made 490 HP and 551 lb/ft torque. That was with the fuel pump, water pump and open headers. I changed the camshaft from a 230/236 to a 236/245, that had a projected loss of 5 lb/ft torque and a gain of about 5 hp.
Last Saturday the club in Sidney had a dyno session at a shop in Victoria, 15 cars, two pulls each to get a base line for further tuning. To try to get a closer comparison, I removed the Q-850 and installed the 800 EPS, The car has manual fuel pump, water pump, power steering, oil cooler, tubular headers, 2-12" dual exhaust with flow through mufflers, twin 30 amp fans, a 140 amp alternator, manual transmission, steel drive shaft, 69 Slomaro c-clip posi rear, 255/60R15 tyres on 15 inch Torque Thrust II wheels, all taking there share of power.
The car made 389 HP and 428 lb/ft torque. I know it's not an exact comparison as I did not engine dyno with the new camshaft, but I'm positive the projected are within five units.. The chassis numbers are 79-80% of an engine dyno. I would have liked to engine dyno it with the new cam and the Q-850 but money ran out long ago.
Rather coincidental both the torque and power numbers are Pontiac engine sizes, 389 and 428!