E-Ram Electric Supercharger
10-18-2019, 06:40 PM
#16
Three Wheelin'
thanks for those numbers Carl, but do you have a idea how much HP it takes to spin the charger ?
10-21-2019, 03:58 PM
#17
Developer
On the 16V cars, is there a delta between US heads and Euro S heads that you see?
10-21-2019, 05:42 PM
#18
Developer
so... I updated my chart as below:
4.5L 16v K-Jet 928 motors tend to make about 13.5 HP per pound of boost.
4.7L 16v L-Jet 928 motors tend to make about 12.5 HP per pound of boost.
4.7L 16V Euro Motor M28/11, 12) made about 16.5 HP per pound of boost.
5.0L 32v LH-Jet 928 1985-86 tend to make about 16.5 HP per pound of boost.
5.0L 32v LH-Jet 928 1987-up tend to make about 25 HP per pound of boost. The GT does a little better with 27 HP per pound.
6.5L 32v 928 motors with fully built out valve-trains can pick up between 29 and 30 HP per pound of boost.
I think the difference between the K-Jet and the L-Jet numbers is the K-Jet was able to fuel the increase in induction air flow better than the L-Jet. Plus, the K-jet motor was 8.5:1 CR, and the L-Jet motors were 9:1 CR. Those two factors combined to make the K-Jet motors respond better to boost than the L-Jet, IMO.
The 300HP Euro M28/11 motor responds to boost better than the other 16v motors, showing the benefit of the larger valves, throttle body, and intake runners it has.
I also think the difference in the response to boost of the M28/44 (1985-86) and M28/42 (1987-up) shows the improvements Porsche made in the 32v heads, intake, and re-designed piston crowns in the M28/42 motors.
4.5L 16v K-Jet 928 motors tend to make about 13.5 HP per pound of boost.
4.7L 16v L-Jet 928 motors tend to make about 12.5 HP per pound of boost.
4.7L 16V Euro Motor M28/11, 12) made about 16.5 HP per pound of boost.
5.0L 32v LH-Jet 928 1985-86 tend to make about 16.5 HP per pound of boost.
5.0L 32v LH-Jet 928 1987-up tend to make about 25 HP per pound of boost. The GT does a little better with 27 HP per pound.
6.5L 32v 928 motors with fully built out valve-trains can pick up between 29 and 30 HP per pound of boost.
I think the difference between the K-Jet and the L-Jet numbers is the K-Jet was able to fuel the increase in induction air flow better than the L-Jet. Plus, the K-jet motor was 8.5:1 CR, and the L-Jet motors were 9:1 CR. Those two factors combined to make the K-Jet motors respond better to boost than the L-Jet, IMO.
The 300HP Euro M28/11 motor responds to boost better than the other 16v motors, showing the benefit of the larger valves, throttle body, and intake runners it has.
I also think the difference in the response to boost of the M28/44 (1985-86) and M28/42 (1987-up) shows the improvements Porsche made in the 32v heads, intake, and re-designed piston crowns in the M28/42 motors.
