This is fabulous info! Thanks so much for taking the time to do this!

 

Being I'm not up to speed as many of you here, my question is why is the GT3 rated at 475 hp and 325 ft lbs. but the dyno reports on Money's car shows much less. What am I interpreting incorrectly?

 

The big difference is that these read outs are for rear wheel horsepower. I'm no dyno expert, but honestly, given the car's performance numbers I would have expected higher numbers even at the rear wheels. Someone correct me if I have that wrong.

 

Very good post. Thanks for investing the time and effort. Very interesting, thanks for posting.

 

Great post Money! All dynos are different, but how conservative did they say their dyno performs? Also, what is the current thinking on drivetrain loss with Porsche's and the 991?

 

Car should be 425 with such low drivetrain loss or so at wheels.

 

Very good info. Did they measure air/fuel ratios? thanks, allan

 

I am also curious about this. The max HP on the dyno charts seems to be ~380HP. Even with 15% drivetrain loss, the HP at the engine crank would work out to be ~437HP. Did the dyno guys give you a reason why it is reading so low?

 

Very informative post by Money as always. Thank you for the info sir! I am plugging my valves in the am to give it a try.

 

I'm sure this has been covered many times over, but please clarify one point for me. Your comments following Run 2, lead me to believe the PSE button only changes the valve operation at idle.

Can we break the valve operation into 3 areas: 1)Idle, 2) off idle up to ~4000rpm, and 3) above 4000rpm?

My understanding of PSE off based on your comments following Run 2 are:
1) valves closed
2) valves closed
3) valves open

With PSE on, I think the valve position would be:
1) valves open
2) valves closed
3) valves open

Is that correct? I thought PSE effected higher rpm as well.

 

I think the dyno jet is the issue. I seem to remember back when i did my 996.2-3 back in 2005 at AWE Performance in PA that Mustang Dyno's gave more accurate results. My car with a Europipe exhaust did 377HP at the wheels.

 

Hugh WroteIt would be interesting to see a Z06 or some other radically different motor on the same Dyno back to back to see what kind of losses are being experienced through the dyno. This is really puzzling.

But as far as the work Matt did:I Love SICK engineers!! Its how humanity moves forward!!! On important $hit like this!!!!

 

This + US Gasoline is junk if you're using Premium US pump gas it's down 4 to 5 octane than the European equivalent.

 

Thanks Matt you did us all a solid.Great job

BTW does anyone know where the electrical plug for the valves are.?
On my 997 GT3 it was right up on the right side of the engine very easy to disconnect and reconnect (maybe 5 seconds )

Elliot

 

As he mentioned in the post the rears are also driving the front rollers which is a greater load. You can do a reverse negative run to calculate loss on dynojets but consistency between changes as opposed to ultimate numbers is more important. Was the throttle position sensor tapped for the various partial throttle runs so they were consistent? Have these been sae normalized? Any chance there was an intake air thermometer set between the runs to monitor loss fom heat gain?