BigPower dyno day Feb 3rd 2008
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Christian and Beccy
- Posts: 344
- Joined: Thu Oct 05, 2006 10:52 pm
- Location: Norwich
-
Christian and Beccy
- Posts: 344
- Joined: Thu Oct 05, 2006 10:52 pm
- Location: Norwich
The confusing ones are usually Air/Fuel plots, because the high-speed lambda sensor is very sensitive and the graphs are detailed. Fuelling curves often wander as the graphs show, so it's not too unusual. Also, we work in 'Lambda' as opposed to 'AFR' that some use as this is a more universal scale.
Also, tuners tend to have their own individual idea as to where they want the Air/Fuel ratio of a specific car that they tune.
When looking at the graph, you'll see a plot with dots through it and one without. The one with dots uses the right hand axis and the one without dots uses the left hand axis.
So, take Ben Connors graphs......
This graph shows estimated Flywheel power vs Estimated Torque. These figures are estimated because the Dyno actually measures Power at the wheels and uses its own method to estimate a 'Flywheel' figure.
In this plot......
.....you'll see Power at the wheels. The other plot with the dots through it is Air/Fuel ratio. Ben's car has a very nice fuelling curve, though a little richer than we would make it, given full control, so he has a little power to be won there with the ability to fully map the fuelling.
In this plot......
......you'll see Power at the wheels again. The other plot is boost. You can see that Ben's car has a nice flat boost curve. This is typical of a Skyline, particularly at low boost (in this case around 0.8 bar).
Sorry to pick you out Ben, but yours was a nice looking graph!!
Some of the graphs have oddities in them. It may be down to interference on the ignition pickup that we use for any one of a number of reasons (such as a mild missfire etc). These were pretty much all explained to the individual owners on the day.
Any more questions, fire away, I'll do my best........
Also, tuners tend to have their own individual idea as to where they want the Air/Fuel ratio of a specific car that they tune.
When looking at the graph, you'll see a plot with dots through it and one without. The one with dots uses the right hand axis and the one without dots uses the left hand axis.
So, take Ben Connors graphs......
This graph shows estimated Flywheel power vs Estimated Torque. These figures are estimated because the Dyno actually measures Power at the wheels and uses its own method to estimate a 'Flywheel' figure.
In this plot......
.....you'll see Power at the wheels. The other plot with the dots through it is Air/Fuel ratio. Ben's car has a very nice fuelling curve, though a little richer than we would make it, given full control, so he has a little power to be won there with the ability to fully map the fuelling.
In this plot......
......you'll see Power at the wheels again. The other plot is boost. You can see that Ben's car has a nice flat boost curve. This is typical of a Skyline, particularly at low boost (in this case around 0.8 bar).
Sorry to pick you out Ben, but yours was a nice looking graph!!
Some of the graphs have oddities in them. It may be down to interference on the ignition pickup that we use for any one of a number of reasons (such as a mild missfire etc). These were pretty much all explained to the individual owners on the day.
Any more questions, fire away, I'll do my best........
That's great! Thanks for taking the time & trouble to do that. I was thinking of some of the 'odder' traces but if it's down to glitches I suppose there's not much point in dwelling on them too much.
Can you say why the HP figures are 327 in one and 247 in the other two. Don't you monitor boost and Lambda together during the run? Also, in what gear are the runs?
Sorry to be so nosey but it is out of genuine interest.
Can you say why the HP figures are 327 in one and 247 in the other two. Don't you monitor boost and Lambda together during the run? Also, in what gear are the runs?
Sorry to be so nosey but it is out of genuine interest.
Handle every stressful situation like a dog. If you can't eat it or hump it, piss on it and walk away!
Boost and Lambda were recorded simultaneously but there are only two side axises so cant show more at a time, hence why they split them over a few graphs.
The 247 whp multiplies up the the flywheel figure using DD's experience of the transmission losses for that type of vehicle I believe. In the case of subaru, it is roughly take the WHP and divide by 0.79 to get the Flywheel figure.
The 247 whp multiplies up the the flywheel figure using DD's experience of the transmission losses for that type of vehicle I believe. In the case of subaru, it is roughly take the WHP and divide by 0.79 to get the Flywheel figure.
Christian, infact thank you for doing mine - very interesting ... I'm looking forward to the power you boys will release once the new ecu is fitted. 
.
Gerry - you also forgetting the horrendous transmission loss on the GTR - hence the difference of nearly 70HP ... my car losses more in transmission than Dunk's punto's has to start with!.
.Gerry - you also forgetting the horrendous transmission loss on the GTR - hence the difference of nearly 70HP ... my car losses more in transmission than Dunk's punto's has to start with!.
Dum spiro, spero
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