What's the typical efficiency factor of the 915 drive train?

[Ho Hum 74]

Just had my 2.7 MFI dyno'd and it came out at 195 hp at the wheels.

Any idea what the factor is? I'm told to divide by .85, but that would put my motor at 230 hp and I'm not really sure it has that much gas.

T

[asphaltgambler]

I understand that 15% is the standing number form the wheels to the flywheel

[Eagledriver]

My personal opinion is 10 percent. It's probably a bit more than that but I use this number to not fool myself into thinking my engine is more powerful than it is. That would put you around 215 which seems close to what I'd expect from a stock 2.7 MFI with "S" cams.

-Andy

[Ho Hum 74]

Andy,

My 2.7 has JE pistons of unknown compression and Elgin Mod-S cams. Should at least get another 10 hp.

T

[Henry Schmidt]

It is reasonable to conclude that if you increase the compression and improve cylinder filling with more lift and duration that the engine will make more horse power.
Is 20 horse power increase with in the realm of reasonable? sure

[Ray 911s]

T -

Where'd you get the dyno test performed?

I'm trying to decide how to build the "spare" 2.7, and it would help to have a leak-down and dyno run on the existing engine so I could calibrate the expense/benefit ratio on investment in the new engine.

[Ho Hum 74]

Porsche Exchange - Highland Park