Dyno Data
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100 bhp per Litre

24 April 2007

Original 1993 Factory 2.5 TBI (SAE Net) ratings:


100 @ 4800 rpm (crank) 133 @ 2800 rpm (crank)
  80 - 85 @ 4800 rpm (est. dyno) 106 @ 2800 rpm (est. dyno)

The Test Vehicle:

1993 Plymouth Voyager Minivan. 2.5L Turbo II running @ max of 11.9 PSI boost, set by Dawes Devices (Gus-designed) controller, stock 1990-91 Turbo I (auto) SBEC, 804, 35 #/hr Injectors set to fuel pressure of 58 - 60 PSI (static). Original fuel pump, and  T3/T04E with 46 trim, running through 3-inch down pipe, 3-inch Random Tech cat, and 3-inch FWD/JRB muffler/exhaust. Both runs performed in 3rd gear on the A-568, manual 5-speed transmission.

FM-modified 2.5 Turbo II (SAE-corrected) dyno results:


231 - 247 @ 4400 rpm (est. crank) 331 @ 3600 rpm (est. crank)
  197 @ 4400 rpm (dyno) 264 @ 3600 rpm (dyno)

Tests Performed by: Phantom Motor Sport
801 - 255 - 3440;  contact: Mark Bremer

The Test Conditions:


76 deg F
Dew Point: 38 deg F
Relative Humidity:  24%
Absolute Pressure:  25.65 in hg
Altitude: 4270 feet
Barometric Pressure: 30.00 inches Hg.
Density Altitude: 6340 feet
Relative Air Density:  83% 
Dyno Correction Factor (SAE):










To better understand the effects of Relative Air Density on your engine's performance, I highly recommend Richard Shelquist's Denisty Altitude & Engine Tuning calculators. 

If you assume 15-to-20% driveline efficiency losses, that would put the crank horsepower @  231-to-247 hp, or about a 2.5X increase in power and torque. A fairly broad torque curve and relatively flat power band are present. Gear changes at 5000 - 5200 RPM drop the engine speed into a range delivering 255+ ft-lb of torque at the wheels!

BTW, the dyno numbers came in about 5-to-8% higher than I had expected, based on the calculations I had run using the TurboFast - TurboCalc from Ray Hall Turbocharging. More than likely the drivetrain losses on the dyno are lower than 20% and/or the volumetric efficiency of the engine is greater than 85%. BFSC is also likely to be below 0.50 lbs/hr. And remember maximum boost was 11.9 PSI. Increasing boost pressure to a relatively conservative 14.7 PSI will provide an estimated additional +20 bhp @ 4400 RPM on the dyno rollers.