04 GXP on the dyno

[Ieatpeople]

I got my car strapped down over the weekend, and got some numbers for you guys.

223hp at the tire, no torque reading due to issues obtaining clean ignition signal. this pull was made in 2nd gear, from 40-85mph
https://www.youtube.com/watch?v=pKPKpWYpBME






My car has 69k miles, and is stock except for magnaflow mufflers. All stock piping to the rear axle, just attached mufflers after the y-pipe.

[Juggernaught]

That sounds spot on with the 275 HP rating of the NorthStar and accounting for 10-15% drivetrain loss.

[Ieatpeople]

i calculated the loss to be 19%, if im making exactly 275hp. I may have a couple more hp in there because of the exhaust, but no way its more than 5hp gained.

[CMNTMXR57]

That issue getting the signal is common when trying to dyno C-N-P coil module setup ignitions such as Northstar's.

But otherwise, sounds pretty spot-on.

Kinda hard to tell what kind of dyno that is (mustang or DynoJet) being an inground setup, but if it's a mustang, those tend to read lower and be closer to real world numbers. So on a DynoJet, you'd have a few more ponies show up even after corrections.

[Ieatpeople]

it is a dynojet unit, my printout is showing "CF: STD". Does that mean its uncorrected or that there is a standard correction factor?

(added dyno graph to first post)

[CMNTMXR57]

Standard correction typically means;

Temp: 77*
Barometric pressre: 29.2" hg
Elevation: 0ft
Humidity: 0%

[1oldman]

Standard correction typically means;

Temp: 77*
Barometric pressre: 29.2" hg
Elevation: 0ft
Humidity: 0%

A different way to put it:

At Mean Sea Level:
For Pilots: At sea level, Altimeter:29.92 in/Hg at 15 °C (59 °F) The "standard day" model of the atmosphere is defined at sea level, with certain present conditions such as temperature and pressure. But other factors, such as humidity, further alter the nature of the atmosphere, and are also defined under standard day conditions:
Density (ρ): 1.225 kg/m³ (0.00237 slug/ft3)
Pressure (p): 1013.25 hPa (14.7 lb/ in2)
Temperature (T): 15 °C (59 °F)
Viscosity (μ): 17.3 µPa·s (3.62 × 10−7 lb s/ft2)[1]
The first three properties are usually referred as "standard day" conditions, which the viscosity aspect is largely ignored throughout the aviation community. However, viscosity, which is affected by humidity levels, plays a key role in aerodynamic drag, which is why it is a key component of standard day conditions. Because it is a key component of drag, it affects the amount of fuel burned per unit of distance travelled.

Hope this confuses things, oh I mean adds clearity. - BC

[nos4blood70]

Nice! First GXP I've seen on a dyno.

[1oldman]

Nice! First GXP I've seen on a dyno.

Most are nice. This one seems especially nice. - BC

[CMNTMXR57]

Standard correction typically means;

Temp: 77*
Barometric pressre: 29.2" hg
Elevation: 0ft
Humidity: 0%

A different way to put it:

At Mean Sea Level:
For Pilots: At sea level, Altimeter:29.92 in/Hg at 15 °C (59 °F) The "standard day" model of the atmosphere is defined at sea level, with certain present conditions such as temperature and pressure. But other factors, such as humidity, further alter the nature of the atmosphere, and are also defined under standard day conditions:
Density (ρ): 1.225 kg/m³ (0.00237 slug/ft3)
Pressure (p): 1013.25 hPa (14.7 lb/ in2)
Temperature (T): 15 °C (59 °F)
Viscosity (μ): 17.3 µPa·s (3.62 × 10−7 lb s/ft2)[1]
The first three properties are usually referred as "standard day" conditions, which the viscosity aspect is largely ignored throughout the aviation community. However, viscosity, which is affected by humidity levels, plays a key role in aerodynamic drag, which is why it is a key component of standard day conditions. Because it is a key component of drag, it affects the amount of fuel burned per unit of distance travelled.

Hope this confuses things, oh I mean adds clearity. - BC

Or another way to put it is to standardize the numbers because what I can pull here, in Chicago, in March, with 40* temps, normal levels of humidity, and relatively high pressure, at ~800 ft above sea level, will get favorable results vs. someone dyno'ing in the swamps of Florida, in July, when it's 110*, 110% humidity, low barometric pressure and probably lower elevation.

The correction adjusts for all that to get to apples to apples numbers, or something like that.

[1oldman]

Standard correction typically means;

Temp: 77*
Barometric pressre: 29.2" hg
Elevation: 0ft
Humidity: 0%

A different way to put it:

At Mean Sea Level:
For Pilots: At sea level, Altimeter:29.92 in/Hg at 15 °C (59 °F) The "standard day" model of the atmosphere is defined at sea level, with certain present conditions such as temperature and pressure. But other factors, such as humidity, further alter the nature of the atmosphere, and are also defined under standard day conditions:
Density (ρ): 1.225 kg/m³ (0.00237 slug/ft3)
Pressure (p): 1013.25 hPa (14.7 lb/ in2)
Temperature (T): 15 °C (59 °F)
Viscosity (μ): 17.3 µPa·s (3.62 × 10−7 lb s/ft2)[1]
The first three properties are usually referred as "standard day" conditions, which the viscosity aspect is largely ignored throughout the aviation community. However, viscosity, which is affected by humidity levels, plays a key role in aerodynamic drag, which is why it is a key component of standard day conditions. Because it is a key component of drag, it affects the amount of fuel burned per unit of distance travelled.

Hope this confuses things, oh I mean adds clearity. - BC

Or another way to put it is to standardize the numbers because what I can pull here, in Chicago, in March, with 40* temps, normal levels of humidity, and relatively high pressure, at ~800 ft above sea level, will get favorable results vs. someone dyno'ing in the swamps of Florida, in July, when it's 110*, 110% humidity, low barometric pressure and probably lower elevation.

The correction adjusts for all that to get to apples to apples numbers, or something like that.

Yes, I believe that even pilots have charts to help them figure out power plant output at take off to make sure they have enough thrust to safely get airborne. - BC

[Sirius]

...I believe that even pilots have charts...

Or probably an app on their phone.