Topic: Opel GT stock dyno - funiest result ever

[Kelu]

ok, I have mentioned I live in Romania which s*cks big time?

Today I went to dyno, below is the result

Should I interpret myself or let you guys do it?

They say the power tested is at flywheel, the car is 2008 Opel GT (Sky RedLine manual) bone stock with 3000 miles on it.

[Sol Asylum]

Thanks for the English subtitles.  When comparing dyno numbers you need to also compare what atmospheric conditions where like (temperature, pressure, humidity) also whats your elevation above sea level. 

What kind of dyno did they use?

Did they give you a RWHP (rear wheel horse power)?   

[DeepBlueGXP]

Interesting curve, do you have an auto?

[jlab8]

That is a extremely strange configuration for the dyno sheet.
RPM & HP versus wheel speed? I don't see a plot for the torque, either.

[Kelu]

Guys, you don't see the whole picture.

Sol Asylum "They say the power tested is at flywheel", they didn't know to tell me type of dyno, elevation, temp, pressure

DeepBlueGXP "2008 Opel GT (Sky RedLine manual)"

alphajesse there are 2 plots in the graphic, one power one tq, the blue line I think is for power cause touches 240hp

So I should explain:
When I got the car in the garage they said my front bumper will hit the ground cause the wheels of the dyno flex and my bumper is too low, I asked them "what the hell are you putting my front wheels on dyno when I'm RWD?" they replied "Uh oh, sorry". After that they didn't know how to turn off the ESC (they don't allow people in the garage, owner of the car has to watch only from panoramic window in the other room). Then tried to start the test very fast, I yeld to them to read the dashboard to have proper temp before starting.

When I saw the graph I was saw amazed:
- 240hp at flywheel (doesn't count the amount) looks like the blue plot is power, that ok, hitting max at 5504 rpm as stated in the left, that almost corect, BUT, how in the hell to have that plot, that plot is a PERFECT, and doesn't look made out of a turbo engine, more close to normally aspirated engine
- the start the test at 2500rpm and stop it at 6000 rpm, WHY? The engine is limited to 6500 rpm, why I don't see that and the drop of power at the highest rpm??
- when is about torque is the funny part: Gents a turbo engine should have a pretty constant line of tq on rpm, right? Why mine is raising all the time. Second, where the turbo is starting??? I don't see that on the graph 3rd There says 236 lb-ft (32.6KgM) at 3420 rpm!!! the yellow plot (i presumed the blue one is the power cause touches 240hp) never hits 32.6 kgM and check the value at 3420rpm as stated in the measurements.

I call this a very big   dyno

[jlab8]

The blue line is definitely horsepower.
The yellow plot appears to be RPM.
The horizontal axis is road speed in Km/h, it is definitely not torque. They killed it at 5500 rpm.

I don't know what kind of correction factor their dyno software is using to determine power at the wheels; but based on the printed output and your description of the service, I don't think it's worth using this dyno shop ever again, as it's obvious they don't really know how to generate useful information with their equipment.

[Bigblau]

I call this a very big  dyno

   Never seen anything like it myself  ...although the numbers seem to be close?  I'd also like to know how they're calculating the flywheel output.  I hope you didn't have to pay too much for this data. 

[snaponbob]

I liked the title of the picture -- "bs_dyno.jpg". Funny. Sorry you got jerked around and wasted your money.

[Kelu]

alphajesse what would be the purpose to display a plot for RPM? On a dyno run the results are power and tq over the rpm, rpm is a scale and not a plot imho, check the left column, there is RPM from 0 - 10 000.
Check the thick vertical lines they match the rpm value when the power and tq max output is reached. I still sustain yello plot is the torque.

I have paid $55 but I got an offer, I pay once and I do 2 testing sessions (a single run on a session), I will try to make a test to see if this a human error or a dyno error. I will go back when I will have my tune installed and tell them I didn't installed anything new and I want just a new run up to 6500 rpm. If the values will be same this means those guys are doing this on purpose and make the graphics on what they believe will be, if I will see a difference in tested power but same graphic then is a dyno error. Either way I will call my money back.

[jonymac]

Good plan Kelu!

[jlab8]

alphajesse what would be the purpose to display a plot for RPM? On a dyno run the results are power and tq over the rpm, rpm is a scale and not a plot imho, check the left column, there is RPM from 0 - 10 000.
Check the thick vertical lines they match the rpm value when the power and tq max output is reached. I still sustain yello plot is the torque.

I have paid $55 but I got an offer, I pay once and I do 2 testing sessions (a single run on a session), I will try to make a test to see if this a human error or a dyno error. I will go back when I will have my tune installed and tell them I didn't installed anything new and I want just a new run up to 6500 rpm. If the values will be same this means those guys are doing this on purpose and make the graphics on what they believe will be, if I will see a difference in tested power but same graphic then is a dyno error. Either way I will call my money back.

The horizontal axis is labeled in Km/hour. That is why there is a plot of RPM.
I don't understand why they omitted a plot for torque, but note that it calls out the RPM where max torque is achieved. If the yellow plot was torque, it would not keep rising as it proceeds to the right. The slope of the torque graph would also not be constant, and the RPM would not be listed vertically.
If the torque was plotted, it would also reach the measured maximum as indicated on the right-side vertical axis.

I'm not sure of the Opel GT gearing, but you will find that that if you read the yellow plot as RPM, the km/h figures on the X axis will correspond to the road speed for the chosen gear and rpm.
Use this calculator to see for yourself:
http://www.turnzero.com/technical_resources.php?resource=gear_calculator
(Results will be in MPH, sorry!)
Failing that, check your road speed at 5500 RPM in the gear the car was tested in. It will be approximately 160 km/h based on an eyeball estimate of the graph.

I don't doubt that they actually generated this graph from running your vehicle on their dyno, but they are clearly not very good at it. I suspect the operator doesn't have a good understanding of what a customer would want in terms of data output, or is unable (either because of crappy software, or lack of knowledge) to adjust the printed output.

I would suggest before you do anything else, ask that they provide you with a new printout of the session that puts RPM on the horizontal axis, power and torque on the vertical axis, and plot them from there. If they cannot do that, then ask for a refund as their service is useless! If they can, then return, have them do a new set of runs and insist that the output is in a useful format.

Also, in the future, I would suggest trying to find a shop that can also provide air/fuel plots with the dyno.

[Kelu]

alphajesse I understand now, this graph was indeed a result of the real test but the problem was the axis, why in the hell to display me rpm over speed  (useless axis).
After I understood that actually are 2 differently graphs ( rpm over speed and power over speed) I figure out everything, I will call them to ask if they can change the axis based on that test.

Normally IF rpm is the X axis (horizontal) and power + torque on Y axis (vertical), putting the axis how they put everything was useless graphs. I checked their website and their demo graph is same but has the torque plot also: http://www.autotest2000.ro/pagini/Motor.html

The test was done in 4th gear and now everything matches

I have found a professional dyno around here, my friends said is brand new and latest model and I checked many results and they look very close to reality especially the power measured is to the wheels but now is relocated to a different place and is unavailable for 2 weeks.

Thanks again for clarification.

[jlab8]

What kind of dyno do they use at the other place?
I'm familiar with a couple of the popular brands in the US and can point you at some tools to view the results on your home computer depending on what they use.

[Kelu]

At the other place they say they use this software:
http://www.mustangdyne.com/MDSoftware/softwareTime.htm

And they can measure up to 16 different channels in the run like boost (up to 5 bars -72 psi), AFR1, AFR2, EGT, different tempepatures. Petty that they didn't have it running, even costs $100 I would go for a test.

[LiquidPT]

Mustang is one of the common dynos over here... I believe DynoJet is the other.

[Kelu]

Yeap I will try to make a run on Mustang when will be available also.

 I have called the guys where I did the dyno, they said if I'm missing the torque plot I will have a new test for free. Things are getting better.

[Kelu]

I went today and made a new test run.

I remember, I'm stock OPEL GT and I have only one modification, the throttle body elbow made out of stainless steel.
[attachment=1]

The white plot is the RPM and the other plots should be read referenced to this one.
The blue plot is power and the orange is the torque in KgM.

The car was a a little bit colder than normal and I did smaller numbers as last time 232 hp instead of 240 hp and 30.5 KgM (300 Nm = 221 lb-ft) instead of 32.6 KgM (320 Nm = 236 lb-ft). Asked them to go the car above 6500 RPM to have a drop line of power and tq.

Now everything looks more normal even they say the power measured is to the engine which is a little bit strange in my point of view, 230-240 hp at the flywheel as they say means 180-200 hp at the wheels which I don't believe cause I have test this car in some drag races and is showing his nominal power.

The strange thing about this new graph is the limiter kicks in at 5800 rpm which I'm sure is above the 6000 RPM, somewhere between 6300 - 6500 RPM.

I will go back after I will have my wester race tune installed.

[DeepBlueGXP]

Each time I go for a dyno, I get 3 runs recorded.  Usually the third run is the best.  Different days have different atmospheric conditions so the difference you're seeing is normal.