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dbaxter_ss
September 12th, 2007, 02:42 PM
Hey Guys
A LOOOOONG time ago I had enhanced the HP calc pid in this thread
http://forum.efilive.com/showthread.php?t=3&page=5
Calculating Instantaneous Net Power

I am on a local musclecar forum ( http://www.musclecar-evolution.com/forums ) and thanks to one of the guys during a heated HP thread the equasion was posted for torque. Having that I figured why not create a calc pid for that also. ( thx skeeveman for the equasion info )

I get so many people asking about a HP number and where it came from, and I only use EFI, no reason to hit a dyno, I have this and a wb02 ( lc1 from greenlight motorsports ) why waste the money to get a number from a dyno when I have everything here.

so on with the new pid.
The formula given was for torque based on hp numbers below
====================
hp=(tq*rpm)/5252
hp*5252=tq*rpm
(hp*5252)/rpm = tq
====================


What I had used for HP in my calc back then:

OLD
*CLC-00-989
hp 0.0 400.0 .0 "(((3554+({GM.FUELREM}*6.350)+185)*{SAE.VSS.mph})* dx({SAE.VSS.mph},6))/8226.63"

CALC.SSHPTRUE6 F60A CLC-00-989 "kW,hp" Performance "SS TRUE HP 06"

But to make it more accurate name: "(car) EFI RWHP Smoothing Factor 6"
Something that can be added, instead of 3554 ( using the customer vehicle weigh pid ), the 185 is the driver weight
NEW
*CLC-00-989
hp 0.0 400.0 .0 "(((3554+({GM.FUELREM}*6.350)+185)*{SAE.VSS.mph})* dx({SAE.VSS.mph},6))/8226.63"

CALC.SSEFIRWHP6 F60A CLC-00-989 "kW,hp" Performance "SS EFI RWHP Smoothing Factor 6"

There are the smoothing factors for 2, 6, 12 depending just like a dyno on the change in polling.

Now for Torque: Change the 9XX to your favorite pid #.

*CLC-00-9XX
hp 0.0 400.0 .0 "(CALC.SSEFIRWHP6*5252)/SAE.RPM"

CALC.SSEFIRWTQ6 F60A CLC-00-9XX "kW,hp" Performance "EFI RWTQ Smoothing Factor 6"

In the end you have a nice rolling dyno giving you EFI HP and TQ numbers.

Its the dawn of a new day, forget Dyno RWHP and RWTQ
Go with EFI RWHP and RWTQ :muahaha:

2002_z28_six_speed
September 14th, 2007, 03:17 PM
Wow! This is really cool.

I did some digging and found something:
http://ohe.cat.com/cda/files/287140/7/LEGT5364.pdf

This PDF put out by CAT has some estimates of rolling resistance and HP required to maintain speed for certain speeds. With the VSS derived PID I think it would be super easy to make the HP calc even more accurate!!

I tried to find you the equation that takes CDA of our cars and translates it into HP lost but couldn't find it for you. Sorry. :( All I know is HP lost would be the square of speed.

Chalky
September 14th, 2007, 05:47 PM
Where do I copy/paste the data? I did one a while ago but forgot how and where to move the data.

TIA

dbaxter_ss
September 15th, 2007, 11:42 AM
User Configuration\calc_pids.txt


Attached my calc_pids for you, easier then cutting and pasting.

just make sure mine don't stomp on any of yours.

articSS
September 19th, 2007, 11:54 AM
could you pleas explain how to do this. im am computer illitertate but im trying. thanks.

blandmiller
September 19th, 2007, 12:08 PM
Check out the calc_pid listed in post #8. It contains the formulas needed for rolling resistance and aero drag. I have not worked on it for a long time, but am willing to continue to de-bug it with others' input.

http://forum.efilive.com/showthread.php?t=2312

Chalky
September 29th, 2007, 04:30 PM
Anyone tried the formula/pids? I tried these today and they seem to be on the low side by possibly 8-9%.

My RwHP using the pids put me @ 400. based on my setup, I am closer to 440 RWHP.

2002_z28_six_speed
September 29th, 2007, 04:39 PM
Which one did you use?


The one that you speed up over a certain range and coast down over it?
Or the regular one?


I have been meaning to make one that does it all at once with my Cda and rolling resistance plugged in as a function of speed in but keep getting distracted. At least this way you don't have to low down over the same range each time.

Only thing about the A+B method is if the wind and grade are constant during the test it figures those in. Other small changes too!

Chalky
September 29th, 2007, 05:07 PM
I used the most current one with txt provided by DBaxter.

Formula is working. I added 100 lbs to formula and HP did increase. maybe car weights are to light.

I didn't realize there was a difference or a process to implement to achieve proper results.

2002_z28_six_speed
October 1st, 2007, 12:36 PM
You stated you were about 40 horses short? How fast were you moving? Aproximately 80 MPH?

I like the equation that DBaxter provided it is easy and simple but depends totally on speed. Wind resistance is left out.

I used info from the Cat link to make up this quadatric regression:
y = ax^3+bx^2+cx+d
where
A = 5.7358e-5*x^3
B = 2.0635e-3*x^2
C = 4.3544e-3*x
D = -5.582e-04

Where X is {SAE.VSS.mph} and Y is HP lost due to rolling resistance and wind resistance.

If you put that into the function then it wouldn't show 0 when you were driving at the same speed all of the time. Also, it would help you realise a number closer to the dyno number of your car.

Of course this is going to vary from car to car due to AERODYNAMICS and fiction from our drivetrains, bearings, and tyres. We should be free from weight.

Chalky
October 1st, 2007, 01:38 PM
I did a 3rd gear pull up to approx 103. To many traction issues with 1st or 2nd gear pulls.

I changed the driver weight to equal mine when i achieved the 403 rwhp. I added another 100 pounds weight to equation and car RWHP jumped to almost 420. same log, just different net weight of driver/car.

I used to always figure 85 lbs was worth a tenth in the quarter mile or approximately 10 HP. not sure how 100 lbs was worth 16 HP though.

I am not critizing anyone's work here. i like the idea of seeing your results of your efforts. Being repeatable, this would be a great way to measure elative gains/losses from the addition of performance accessories. Furthermore, there are weather stations that can give barometric readings to help calibrate changes in hP based on the time of your performance runs.

Unfortunately, I ran out of money just before i found this handy dandy performance pid. :)

I believe the goal was to create a pid that would show similar results in HP/TQ as your would experience on a dyno. On the other hand, how much HP is used to overcome drag to get to 100 MPH.

2002_z28_six_speed
October 1st, 2007, 03:57 PM
# ================================================== ============================
# File details
# ------------
#
# This section defines various details about the file format.

*FILE

#Parameter Value Description
#---------- ---------------- ---------------------------------------------------
VERSION 7.1.1 File version
DECSEP . Decimal separator used in this file



# ================================================== ============================
# Units
# -------------------
# See sae_generic.txt for more information on the *UNITS section

*UNITS

#Code System Abbr Description
#-------- ---------- -------- -------------------------------------------------------------
MPG Imperial MPG "MPG"
LPK Metric LPK "Litre X KM"




# ================================================== ============================
# Add slot definitions here
# --------------------------------
# See sae_generic.txt for more information on "SLOT" formats
#
#Units Low High Fmt Expression
#------------ ------------- ------------- ---- --------------------------------------------------------------

################################################## #################################
#Wide Band PID
*CLC-00-001
V 0.0 5.0 0.1 "{EXT.AD1}"
AFR 10.00 16.8 0.1 "{EXT.AD1}*1.36 + 10"
factor 0.5 1.5 0.01 "({EXT.AD1}*1.36 + 10) / {GM.AFR}"


################################################## #################################
#Fuel Economy
*CLC-00-002
MPG 0.00 99.99 .1 "{SAE.VSS.mph}/({GM.INJFLOW.lbpm} * {GM.IBPW1} * {SAE.RPM} * 4 / 6250)"
LPK 0.00 99.99 .1 "235.2145584/{SAE.VSS.mph}/({GM.INJFLOW.lbpm} * {GM.IBPW1} * {SAE.RPM} * 4 / 6250)"


################################################## #################################
#Aero Drag, power lost to go down road without changing speed.
*CLC-00-003
hp -200.00 600.00 .1 "0.000070146*{SAE.VSS.mph}^3-0.0007566*{SAE.VSS.mph}^2+0.13894268*{SAE.VSS.mph}-0.1634172"
kW -200.00 600.00 .1 "0.745699872*(0.000070146*{SAE.VSS.mph}^3-0.0007566*{SAE.VSS.mph}^2+0.13894268*{SAE.VSS.mph}-0.1634172)"


################################################## #################################
#Raw Power, power you are using to to change speed.
*CLC-00-004
hp -200.00 600.00 .1 "((gvmlb()+({GM.FUELREM}*6.350)+130)*{SAE.VSS.mph}) *dx({SAE.VSS.mph},6)/8226.63"
kW -200.00 600.00 .1 "0.745699872*(((gvmlb()+({GM.FUELREM}*6.350)+130)*{ SAE.VSS.mph})*dx({SAE.VSS.mph},6))/8226.63"


################################################## #################################
#Raw Force, force that must be applied to change speed.
*CLC-00-005
ftlb -200.00 600.00 .1 "({CALC.RawHP}*5252)/{SAE.RPM}"
Nm -200.00 600.00 .1 "1.356*({CALC.RawHP}*5252)/{SAE.RPM}"


################################################## #################################
#Power Demanded, Real wheel power it is taking to go down road AND change speed.
*CLC-00-006
hp -200.00 600.00 .1 "{CALC.RawHP}+{CALC.Powerlost}"
kW -200.00 600.00 .1 "0.745699872*({CALC.RawHP}+{CALC.Powerlost})"

# ================================================== ============================
*PRN - Parameter Reference Numbers
# --------------------------------
# See sae_generic.txt for more information on the *PRN section
#
#Code PRN SLOT Units System Description
#------------------------- ---- ------------ ---------------- ---------------- ------------------------------------------
################################################## #################################
#Wide Band PID
CALC.LM1 F021 CLC-00-001 "AFR,V,factor" Custom "A Custom PID for the LM1 WB in Voltage, AFR, or BEN."



################################################## #################################
#Fuel Economy
CALC.FuelEcon F031 CLC-00-002 "MPG,LPK" Custom "MPG o L/100kM."



################################################## #################################
#Aero Drag, power lost to go down road without changing speed.
CALC.Powerlost F041 CLC-00-003 "hp" Custom "HP Lost from air and rolling resistance."



################################################## #################################
#Raw Power, power you are using to to change speed.
CALC.RawHP F051 CLC-00-004 "hp,kW" Custom "RealRoadPower, Net HP/kW after grade, wind, rolling resis, ect."



################################################## #################################
#Raw Force, force that must be applied to change speed.
CALC.RealRoadTorque F061 CLC-00-005 "ftlb,Nm" Custom "RealRoadMoment, Net Ftlb/Nm after grade wind rolling resis ect."



################################################## #################################
#Power Demanded, Real wheel power it is taking to go down road AND change speed.
CALC.PowerDemanded F071 CLC-00-006 "hp" Custom "Estimate of crank hp. hp from accel + drag + aero."

Chalky
October 1st, 2007, 04:14 PM
I love beta testing! :)

the 78 HP used to overcome drag @ 100 MPH, is that supposed to be crank or RWHP? I am assuming this would be crank HP.

Help me out here but assuming a known RWHP of approx 440 RWHP at approx 6600 RPM. I would assume a frictional loss of approx 75 hp putting my crank HP at approx 515.

How close could you get to actual crank and /or rwhp with the equations?

i haven't dyno'd my setup but it is a common package developed by Tony Mamo of AFR. 440ish RWHP is common. Tony mamo actually achieved around 475 with some fine tuning.

A stock 02 Z06 puts down about 354 RWHP stock and can achieve 171 MPH top speed in 5th gear. Does this help to determine HP lost to drag and friction?

2002_z28_six_speed
October 1st, 2007, 06:57 PM
Well. I modded it to include that data point. Still have to test it to make sure EFI calculates it right. I got some values earlier driving around. Now just needs tweaking.

[edit 02 Ott 2007]

Still haven't test it yet. Haven't touched the car for awhile. Any see if the aero drag equation makes reasonable numbers?

blandmiller
October 3rd, 2007, 01:52 PM
I don't think the third order polynomial approximation formula listed previously will work. I don't see any values for the a, b, or c components of the equasion. I believe that equasion works if you have determined the a, b, & c components for a vehicle at a specific speed and want to know what the equivalent losses would be at other speeds.

I just tried my equasion with the data that was provided in the CATERPILLAR link and achieved the same results they listed.

The formula for 'Power Consumed by Aero Drag & Rolling Resistance' is:

P(HP)=(Crr X W X S + 0.5 X Rho X Cd X Fa X S X S) X S / 375
The plus sign separates the rolling resistance calc from the aero drag calc

Units are:
Crr (unitless coefficient of rolling resistance)
W (weight of vehicle & driver in pounds)
S (vehicle speed in miles per hour)
Cd (unitless vehicle specific coefficient of drag)
Fa (vehicle specific frontal area in square feet)
Rho (air density {units & derivation are cumbersome} I use the following formula for Rho:

(Baro/(Temp+460))/22.0824
Units are:
Baro (Barometric pressure in "Hg)
Temp (Ambient temperature in Degrees F)

Try it out and see what you get. These calculations should get you very close to the power at the rear wheels that is lost. They will only be as accurate as the data you use; ie, have good weight, Crr, Cd, & Fa values for your make, model.

Using the data I found for a 2002 Z28 (Cd=0.33, Fa=22, W=3410+150), I get the following aero drag losses:
50 Mph = 17Hp
100 Mph = 49Hp
160 Mph = 203Hp

My Crr equasion may not be as accurate as I thought. It appears that the losses are very dependant on inflation pressure of the tires. I will do some more research and post back the findings.

2002_z28_six_speed
October 4th, 2007, 08:51 AM
I would argee on the tyres' inflation being a huge issue. I have seen a couple MPG difference from bad inflation. So, if you have changed your tyres you are going to have error there.

Do you think your 160MPH number is low? I based my data solely from the CAT data and got 289.93 HP for 160MPH. Also, I know that is about how fast you can push a stock Z28.

I had my equation written funny, this is it:
0.000070146*{SAE.VSS.mph}^3-0.0007566*{SAE.VSS.mph}^2+0.13894268*{SAE.VSS.mph} -0.1634172
So if I plug in 55MPG it turns into
0.000070146*55^3-0.0007566*55^2+0.13894268*55 -0.1634172= 16.8hp

It would be super easy to turn your equation into a calc PID. All the parameters are already there.

blandmiller
October 4th, 2007, 11:19 AM
I am very confident of my aero drag number for the Z28 @ 160 Mph is accurate. I have confirmed it using the SAE standard, several online calculators, and 2 vehicle performance software packages.

How did you get 290 Hp @ 160 Mph from the CAT data? I don't remember seeing any equasions in the document. I get an aero drag loss of 268 Hp using the CAT data. The automobile data they list is; Cd=.32, and Fa of 30. The Z28 has better aero drag values than the example they used.

I still have not figured out the equasion for Crr that takes tire inflation pressure into consideration. The information I still need is 'how to calculate the speed effect coefficient'.

I already put my equasion into a calculated PID. I never could get all of the calculations to work together.

I just looked at your equasion again and realized that I misunderstood how you derived it. Is it specific to the CAT automobile listed or are you entering your own Crr and vehicle weight somewhere else?

blandmiller
October 5th, 2007, 11:02 AM
I assumed that was your method. The only flaw I see is that you have to know the impact of the vehicle specific values to make the regression accurate when you convert it to your vehicle specific values.

After much more research, I believe the Crr for the majority of all passenger tires manufactured after 2000 are in the range of 0.0085 - 0.0115. I still have not found any more information concerning the speed effect coefficient.

Chalky
October 22nd, 2007, 03:42 AM
Is this still alive or has it died?

gto_in_nc
November 4th, 2007, 05:16 AM
What are you using now?

2002_z28_six_speed
November 9th, 2007, 04:32 PM
Still not finished. Will edit this post later. Waiting on suggestions or examples of more real life data.

http://www.ls1tech.com/forums/attachment.php?attachmentid=109647&stc=1&d=1194683992
I would use the NEW PID. I will edit the OLD PID. The OLD pid is based off data points of cars in general. The NEW pid is based off the scientific calc from our cars. Really the whole things just bumps up the HP values a little. It matters though when speeding in 4th gear. Now if you guys get me data on a tilt sensor I can add in inclines heheh. That is simply based off the vehicles weight and how much of it is going to fight the car based off + or - cos(inclination)*mass*gravity!


*CLC-00-004
hp -200.00 600.00 .1 "0.00006*{SAE.VSS.mph}^3-0.0006*{SAE.VSS.m# ================================================== ============================
# File details
# ------------
#
# This section defines various details about the file format.

*FILE

#Parameter Value Description
#---------- ---------------- ---------------------------------------------------
VERSION 7.1.1 File version
DECSEP . Decimal separator used in this file



# ================================================== ============================
# Units
# -------------------
# See sae_generic.txt for more information on the *UNITS section

*UNITS

#Code System Abbr Description
#-------- ---------- -------- -------------------------------------------------------------
MPG Imperial MPG "MPG"
LPK Metric LPK "Litre X KM"




# ================================================== ============================
# Add slot definitions here
# --------------------------------
# See sae_generic.txt for more information on "SLOT" formats
#
#Units Low High Fmt Expression
#------------ ------------- ------------- ---- --------------------------------------------------------------

################################################## #################################
#Wide Band PID
*CLC-00-001
V 0.0 5.0 0.1 "{EXT.AD1}"
AFR 10.00 16.8 0.1 "{EXT.AD1}*1.36 + 10"
factor 0.5 1.5 0.01 "({EXT.AD1}*1.36 + 10) / {GM.AFR}"


################################################## #################################
#Fuel Economy
*CLC-00-002
MPG 0.00 99.99 .1 "{SAE.VSS.mph}/({GM.INJFLOW.lbpm} * {GM.IBPW1} * {SAE.RPM} * 4 / 6250)"
LPK 0.00 99.99 .1 "235.2145584/{SAE.VSS.mph}/({GM.INJFLOW.lbpm} * {GM.IBPW1} * {SAE.RPM} * 4 / 6250)"


################################################## #################################
#Aero Drag, power lost to go down road without changing speed.
*CLC-00-003
hp -200.00 600.00 .1 "0.000070146*{SAE.VSS.mph}^3-0.0007566*{SAE.VSS.mph}^2+0.13894268*{SAE.VSS.mph}-0.1634172"
kW -200.00 600.00 .1 "0.745699872*(0.000070146*{SAE.VSS.mph}^3-0.0007566*{SAE.VSS.mph}^2+0.13894268*{SAE.VSS.mph}-0.1634172)"


################################################## #################################
#Raw Power, power you are using to to change speed.
*CLC-00-004
hp -200.00 600.00 .1 "((gvmlb()+({GM.FUELREM}*6.350)+130)*{SAE.VSS.mph}) *dx({SAE.VSS.mph},6)/8226.63"
kW -200.00 600.00 .1 "0.745699872*(((gvmlb()+({GM.FUELREM}*6.350)+130)*{ SAE.VSS.mph})*dx({SAE.VSS.mph},6))/8226.63"


################################################## #################################
#Raw Force, force that must be applied to change speed.
*CLC-00-005
ftlb -200.00 600.00 .1 "({CALC.RawHP}*5252)/{SAE.RPM}"
Nm -200.00 600.00 .1 "1.356*({CALC.RawHP}*5252)/{SAE.RPM}"


################################################## #################################
#Power Demanded, Real wheel power it is taking to go down road AND change speed.
*CLC-00-006
hp -200.00 600.00 .1 "{CALC.RawHP}+{CALC.Powerlost}"
kW -200.00 600.00 .1 "0.745699872*({CALC.RawHP}+{CALC.Powerlost})"

# ================================================== ============================
*PRN - Parameter Reference Numbers
# --------------------------------
# See sae_generic.txt for more information on the *PRN section
#
#Code PRN SLOT Units System Description
#------------------------- ---- ------------ ---------------- ---------------- ------------------------------------------
################################################## #################################
#Wide Band PID
CALC.LM1 F021 CLC-00-001 "AFR,V,factor" Custom "A Custom PID for the LM1 WB in Voltage, AFR, or BEN."



################################################## #################################
#Fuel Economy
CALC.FuelEcon F031 CLC-00-002 "MPG,LPK" Custom "MPG o L/100kM."



################################################## #################################
#Aero Drag, power lost to go down road without changing speed.
CALC.Powerlost F041 CLC-00-003 "hp" Custom "HP Lost from air and rolling resistance."



################################################## #################################
#Raw Power, power you are using to to change speed.
CALC.RawHP F051 CLC-00-004 "hp,kW" Custom "RealRoadPower, Net HP/kW after grade, wind, rolling resis, ect."



################################################## #################################
#Raw Force, force that must be applied to change speed.
CALC.RealRoadTorque F061 CLC-00-005 "ftlb,Nm" Custom "RealRoadMoment, Net Ftlb/Nm after grade wind rolling resis ect."



################################################## #################################
#Power Demanded, Real wheel power it is taking to go down road AND change speed.
CALC.PowerDemanded F071 CLC-00-006 "hp" Custom "Estimate of crank hp. hp from accel + drag + aero."ph}^2-0.0275*{SAE.VSS.mph}"

*CLC-00-005
hp -200.00 600.00 .1 "((3600+({GM.FUELREM}*6.350)+135)*{SAE.VSS.mph})*dx ({SAE.VSS.mph},2)/8226.63"
kW -200.00 600.00 .1 "0.745699872*(((3600+({GM.FUELREM}*6.350)+135)*{SAE .VSS.mph})*dx({SAE.VSS.mph},2))/8226.63"

*CLC-00-006
ftlb -200.00 600.00 .1 "({CALC.OldRoadPower.hp}*5252)/{SAE.RPM}"
Nm -200.00 600.00 .1 "1.356*({CALC.OldRoadPower.hp}*5252)/{SAE.RPM}"

*CLC-00-007
hp -200.00 600.00 .1 "{CALC.OldRoadPower.hp}+{CALC.OldDragLoss.hp}+{CALC .NEWRollFric}"

*CLC-00-008
hp -200.00 600.00 .1 "0.00001917*{SAE.VSS.mph}^3-0.001789*{SAE.VSS.mph}^2+0.13239343*{SAE.VSS.mph} -0.0004866"

*CLC-00-009
hp -200.00 600.00 .1 "0.000053295*{SAE.VSS.mph}^3"

*CLC-00-010
hp -200.00 600.00 .1 "{CALC.OldRoadPower.hp}+{CALC.NEWRollFric.hp}+{CALC .NEWAeroFric.hp}"



CALC.OldDragLoss F051 CLC-00-004 "hp" Custom "OLD Aero Drag Losses."
CALC.OldRoadPower F061 CLC-00-005 "hp,kW" Custom "OLD HP Estimated From Accel, Road Power."
CALC.OldRoadTorque F071 CLC-00-006 "ftlb,Nm" Custom "OLD Torque Estimated from Accel, Road Torque."
CALC.oldCrankHP F081 CLC-00-007 "hp" Custom "OLD Estimated Crank HP, RoadPower + Drag Losses."

CALC.NEWRollFric F091 CLC-00-008 "hp" Custom "Newer Estimate of Rolling friction, 2002 Camaro."
CALC.NEWAeroFric F092 CLC-00-009 "hp" Custom "Newer Estimate of Aero Friction, 2002 Camaro."
CALC.NEWCrankPower F093 CLC-00-010 "hp" Custom "Newer Estimate of HP from Accel plus Drag Losses--> New Estimated Crank, 2002 Camaro."

Chalky
November 19th, 2007, 09:00 AM
don't know if this would help but I did dyno recently after using the HP/TQ pids. Dyno results were peak @ 442 while calced in EFI was approx 403 RWHP.

Chalky
November 19th, 2007, 12:46 PM
I was working off a prior setup without the variables other than car weight, driver weight.

What I may try and do tonight is to compare calculated Hp with actual and see if the results are consistent throughout the rpm range.

2002_z28_six_speed
November 19th, 2007, 12:48 PM
I was working off a prior setup without the variables other than car weight, driver weight.

What I may try and do tonight is to compare calulated Hp with actual and see if the results are consistent throuhout the rpm range.

That would be neat. Can you post a log and then the dyno graph? I can plot the approximate error between the two. Maybe that will show what is wrong.

Chalky
November 19th, 2007, 12:53 PM
Should not be a problem.

Chalky
November 19th, 2007, 01:26 PM
Excel SS and EFI Log.

My dyno file was given to me in file format rather than a printout. I transferred the data to an excel file.

Chalky
March 2nd, 2008, 01:55 PM
Any news to report?

vatman02
March 30th, 2008, 03:15 PM
If it helps, here are my 2 dyno run log files. The first is 3 hp less then the second. My hp pid showed over 1k hp which is incorrect. The correction factor was 1.20 so the actual #'s are 603 rwhp on the second run.

2002_z28_six_speed
April 1st, 2008, 05:05 PM
I will look at it here in a little bit. Very busy with work.

The only thing with running this pid on a dyno is that it will be off because u dont have the loading from air resistance on the dyno. Maybe better to use the factory power pid for the dyno

vatman02
April 2nd, 2008, 10:25 AM
I did'nt think of that. I'll try that next time go to the dyno.

Chalky
April 2nd, 2008, 10:35 AM
Just curious but what kind of hp losses would you expect to see lost to air drag at various points, like 40,60,80,90,100?

I did pick a G Meter over the winter just for fun and a comparison.

2002_z28_six_speed
April 4th, 2008, 03:51 PM
Just curious but what kind of hp losses would you expect to see lost to air drag at various points, like 40,60,80,90,100?

I did pick a G Meter over the winter just for fun and a comparison.

How do your results from the G meter compare? I used to have one and it was farily accurate AFTER you got off the line. Mine failed at the rubber ball mount.

Chalky
April 4th, 2008, 05:00 PM
How do your results from the G meter compare? I used to have one and it was farily accurate AFTER you got off the line. Mine failed at the rubber ball mount.

Haven't tried it yet. Possible give it a try over the weekend and post up my results.

Chalky
April 13th, 2008, 02:43 PM
Sorry but it has been to cold to get car to hook up. Throw in some rain/snow and just cold air. I will try and get some results soon with GTech.

ls698ta
May 2nd, 2008, 07:19 AM
im lost!!

Chalky
May 29th, 2008, 01:00 PM
I ended up selling the GTech so never did the comparison. I am still using the calc'd RWHP and it just seems difficult to get a reliable reading. I use 3rd gear but results are a bit inconsistent. The data is less than linear so it makes it hard to compare to back to back runs.

2002_z28_six_speed
July 1st, 2008, 03:58 PM
Wretched that we haven't solved it, yet. I know it sounds so simple. There are just so many things not adding up.

Like time after time I have heard that power is the same no matter what gear. Power doesn't care what RPM is doing. But torque does double as RPM doubles. Maybe we have the equation wrong then. Maybe there is a different way to calculate the whole equation.

Obviously the equation we have been shown to use doubles with lower gears....

http://www.madsci.org/posts/archives/2005-05/1115165795.Eg.r.html
http://wotid.com/content/view/13/36/

2002_z28_six_speed
July 1st, 2008, 03:58 PM
im lost!!

It's all good.

nevinsb
July 3rd, 2008, 11:50 PM
So is the axle torque independent of engine torque? I would think that speed would affect axle torque but not engine torque:confused:

2002_z28_six_speed
July 4th, 2008, 06:08 AM
Axle torque is independent of engine torque. Engine power should not be independent of axle power.

DmaxHawk
September 25th, 2008, 11:37 AM
Hey guys, I've been reading about this wanting to make a RWHP and RWTQ PID but I'm not sure at what to do. What do I have to do? I've been reading about putting in formulas but dont know where to put them. If someone could have a step-by-step process to make them show up I would greatly appreciate it.

Thanks
-Sal

2002_z28_six_speed
October 3rd, 2008, 06:06 PM
Hey guys, I've been reading about this wanting to make a RWHP and RWTQ PID but I'm not sure at what to do. What do I have to do? I've been reading about putting in formulas but dont know where to put them. If someone could have a step-by-step process to make them show up I would greatly appreciate it.

Thanks
-Sal

use the search feature on your computer to locate a file called calc_pids.txt

that is where this info will go!

DmaxHawk
October 5th, 2008, 08:18 AM
use the search feature on your computer to locate a file called calc_pids.txt

that is where this info will go!

Thanks! I got the pid to come up on the pid list but I can seem to get a gauge or chart made to log the results..Any idea on how to do this?

Thanks

Extinct
March 27th, 2009, 03:15 PM
Found this thread and thought I would contribute. You can empirically measure your real world drag using a coast down test. By sorta using the power calc in reverse you can figure the resistance. The aero drag increases with the square of speed and the rolling resistance is a linear funcion, both have coefficients of course, however by measuring the coastdown and plugging the data in your can use a curvefit and get a real life measure of the two coefficients.

2002_z28_six_speed
April 14th, 2009, 02:45 AM
Found this thread and thought I would contribute. You can empirically measure your real world drag using a coast down test. By sorta using the power calc in reverse you can figure the resistance. The aero drag increases with the square of speed and the rolling resistance is a linear funcion, both have coefficients of course, however by measuring the coastdown and plugging the data in your can use a curvefit and get a real life measure of the two coefficients.

This is entirely true and the best way to get the data if you can find a flat spot.

I wish I could pursue this more but I no longer have a laptop. I am pretty pissed about that... Not much I can do. I'd rather not spend the money on a new one.

scdyne
April 30th, 2009, 07:06 AM
This is entirely true and the best way to get the data if you can find a flat spot.

I wish I could pursue this more but I no longer have a laptop. I am pretty pissed about that... Not much I can do. I'd rather not spend the money on a new one.

Why in the world does it require real time logging to the scan tool for this PID to work?
Maybe it's just me, but I can't get it to work when uploading the logs from FlashScan and displaying them in the ScanTool.

I hate having to export everything to MatLab to play with the HP, TQ results.

joecar
April 30th, 2009, 07:19 AM
In the scantool, open your log file, goto the PIDs tab and select the calc pids you require...

Then on the chart display, pick a corner of a chart and do rightclick and select one of those calc pids.

scdyne
April 30th, 2009, 07:29 AM
yes, yes, in theory I know how to do it, but in function my calculated PID for Power_RW doesn't display anything but a value of zero.

I have Build 84 and the default PID in the sae_generic.txt
Yes the gvmlb() is valid as is the Power_RW PID.

something is a miss and I just can't see it..

joecar
April 30th, 2009, 09:42 AM
Try this: in your calc_pids.txt make a separate calc pid for each component of your power calc pid, and disiplay each of those on the chart tab.

5.7ute
April 30th, 2009, 11:14 AM
yes, yes, in theory I know how to do it, but in function my calculated PID for Power_RW doesn't display anything but a value of zero.

I have Build 84 and the default PID in the sae_generic.txt
Yes the gvmlb() is valid as is the Power_RW PID.

something is a miss and I just can't see it..

In the scan tool with the log loaded go to Edit/log file information/vehicle options and make sure the information is recorded in here.(weight etc)

Redline Motorsports
April 30th, 2009, 02:46 PM
Boy this is a oldy!

Interestingly we have a new dyno coming in two weeks. The dyno can output just about any of the data it stores. We are going to configure one of the analog 0-5 volt outputs for HP and one for torque so we can log HP/TQ in FS!

Will be kind of nice to have all this in one log. Now how to we tie it into RTAC spark timing adjustments:doh2:

Howard

5.7ute
April 30th, 2009, 03:00 PM
They are doing some cool stuff with the new mainline dynos over here for finding not only optimum spark but best AFR for each load point. Check out this thread http://www.ls1.com.au/forum/showthread.php?t=115504&page=15
Going back the other way you could also write a pid for RTACS to optimise AFR with your new dynos output. What interesting times you have ahead.

scdyne
May 15th, 2009, 07:08 AM
I still haven't figured out WTF is going wrong with my set-up.
First weather I set the dx({SAE.VSS.mph},50 or dx({SAE.VSS.mph},6 I see no difference in the data. I get sawtooth HP readings and my VSS only updates every 6 to 10 frames.

Also to me it STILL makes no sense and has no obvious reason for working in pass through, but not when I import from the logs.

kostelacd69
July 12th, 2009, 04:01 PM
can someone help me. lol i just dont have any idea where to put my vehicle weight to get rwhp. i can get fwhp and tq but no rearwheel. any ideas where to ut this info? thanks

5.7ute
July 12th, 2009, 04:09 PM
You can put it in under Edit/default customer details. With a log you have already done go to Edit/log file information/vehicle options.

kostelacd69
July 12th, 2009, 04:13 PM
i put my info in there already and it didnt do anything do i have to do something special to the pids

5.7ute
July 12th, 2009, 04:54 PM
i put my info in there already and it didnt do anything do i have to do something special to the pids

I have never had to, then again I dont play around with those pids much anymore.
You could try putting your vehicle weight directly into the pid.

kostelacd69
July 12th, 2009, 05:59 PM
ok thanks i got it to work its saying 300 rwhp and 600 fwhp mine dyno told me 500 rwhp and it runs mid 12s at 5300 lbs so im not so sure it right but its all good thanks again

GMPX
July 13th, 2009, 10:38 AM
They are doing some cool stuff with the new mainline dynos over here for finding not only optimum spark but best AFR for each load point. Check out this thread http://www.ls1.com.au/forum/showthread.php?t=115504&page=15
Going back the other way you could also write a pid for RTACS to optimise AFR with your new dynos output. What interesting times you have ahead.
We have been working with Mainline / DynoLog over the last month, we have some VERY cool stuff coming soon that will make some jaws drop :gossip:

5.7ute
July 13th, 2009, 01:07 PM
We have been working with Mainline / DynoLog over the last month, we have some VERY cool stuff coming soon that will make some jaws drop :gossip:

I am looking forward to seeing what you guys have come up with. Any hints:pokey:

DmaxHawk
July 13th, 2009, 01:37 PM
We have been working with Mainline / DynoLog over the last month, we have some VERY cool stuff coming soon that will make some jaws drop :gossip:

What a tease:hihi:

Cant wait!:cheers:

GMPX
July 13th, 2009, 03:34 PM
I am looking forward to seeing what you guys have come up with. Any hints:pokey:Sorry, lips are sealed for the moment. Oh, this won't be limited to Mainline either, it's just that Paul and Andrew at DynoLog hooked up on the implementation first. The features will be released in stages, but even so, the first one will have people very excited.
We are aiming for something to release for testing by the end of the month, it depends how Black Box Reading goes, Paul will be finishing off the dyno project once BBR is in to beta.

Cheers,
Ross

scdyne
July 25th, 2009, 09:51 AM
For me it turns out that for some reason EFILive just wont read gvmlb() from my customer information. When I modify the PID to a staic value of say 3200 it displays something, but the gvmlb() just doesn't work.
Possibly because I added my vehicle to the list, but it's the same as the others and should work.

Also I still can't get rid of the sawtooth due to the lack of resolution in VSS signal.
What could I possibly have wrong that prevents it from updating more than a few times a second.
I made a specific BBL data set of literally RPM, VSS and WB02 yet it still only updates at around 2 Hz for the VSS.

How can I get it to log VSS at 40 Hz?

Devil_Z
May 24th, 2010, 12:53 PM
Sounds pretty cool. How accurate have you guys gotten it now? I'm getting efi live soon and that would be a nice feature to have on my car and truck

vzsv8
June 29th, 2010, 01:59 PM
I should have read this earlier, I always had the feeling that I needed to add the weight of my fat ass to get close to an accurate figure.
Cheers, Steve

Chalky
July 26th, 2010, 02:43 AM
We have been working with Mainline / DynoLog over the last month, we have some VERY cool stuff coming soon that will make some jaws drop :gossip:

Just curious but any updates to this thread?