Not all dynos are equal - truth !!!
05-30-2013, 06:47 PM
#1
Banned
Thread Starter
Not all dynos are equal - truth !!!
Guys, take a look at this video, which starts as a joke, but actually explains how a Mustang dyno can be 'modified' to show different numbers.
That's the reason why I only use Dynojet
Mustangs are as good as the person who runs them. Dynojets, in contrary, can't be messed with.
That's the reason why I only use Dynojet
Mustangs are as good as the person who runs them. Dynojets, in contrary, can't be messed with.
05-30-2013, 06:55 PM
#2
Addict
Rennlist Member
Rennlist Member
We have a C6 ZR1 running slicks in NASA-TT that puts barely 502whp, on a dynojet. My Fiat puts 397whp on a dynojet.
The best dyno is a GPS and a set of computer scales.
The best dyno is a GPS and a set of computer scales.
05-31-2013, 12:48 AM
#4
Even with Dynojets, you can manipulate the numbers. Prior to every run, you should read temperature, humidity and barometric pressure. Because you can manually enter these values, this manipulates the SAE and STD conversions. Whenever I dyno, I always have them take current readings for every run to calculate correctly; otherwise there is no way to compare results even on the same dyno and on the same day.
Also be sensitive to correction factors. STD and SAE are not the same. A dyno in STD is about ~3% higher than SAE. For consistency to correct to standard temperature, humidity and barometric pressure; I always look at my dyno charts as SAE corrected. Since anyone can download WinPEP for free, Dynojet's dyno graph maker; there is simply no excuse hiding run conditions or not using SAE factors. Just copy your dyno run files on a flash drive and take them with you to run your own charts. I have criticized others for using factors other than SAE to make their numbers look better, like this thread on an RS 4.0 dyno as a good case:
https://rennlist.com/forums/997-gt2-...4-0-chart.html
At SAE, it would have shown ~442 RWHP versus the 457 RWHP at STD.
Here is the dyno of my 100% stock 2010 GT3 on a Dynojet 500. Please note that the run conditions are clearly shown for each run and the associated correction factor is listed, hence clearly showing no manipulation on the values. Note also that for SAE it actually corrected down and not up due to favorable test conditions. I could have shown the dyno in raw data or STD if I wanted to boast higher numbers, but not accurate for a real world comparison. Note the date and time that the data was also taken is listed. For early May in Texas before noon, 76 deg F is pretty normal. If we had used a lot higher temp of say 95 deg F for the same date and time, this would have easily bumped the numbers up with a higher correction factor and shown I was intentionally trying to manipulate the numbers.
Also be sensitive to correction factors. STD and SAE are not the same. A dyno in STD is about ~3% higher than SAE. For consistency to correct to standard temperature, humidity and barometric pressure; I always look at my dyno charts as SAE corrected. Since anyone can download WinPEP for free, Dynojet's dyno graph maker; there is simply no excuse hiding run conditions or not using SAE factors. Just copy your dyno run files on a flash drive and take them with you to run your own charts. I have criticized others for using factors other than SAE to make their numbers look better, like this thread on an RS 4.0 dyno as a good case:
https://rennlist.com/forums/997-gt2-...4-0-chart.html
At SAE, it would have shown ~442 RWHP versus the 457 RWHP at STD.
Here is the dyno of my 100% stock 2010 GT3 on a Dynojet 500. Please note that the run conditions are clearly shown for each run and the associated correction factor is listed, hence clearly showing no manipulation on the values. Note also that for SAE it actually corrected down and not up due to favorable test conditions. I could have shown the dyno in raw data or STD if I wanted to boast higher numbers, but not accurate for a real world comparison. Note the date and time that the data was also taken is listed. For early May in Texas before noon, 76 deg F is pretty normal. If we had used a lot higher temp of say 95 deg F for the same date and time, this would have easily bumped the numbers up with a higher correction factor and shown I was intentionally trying to manipulate the numbers.
05-31-2013, 01:12 AM
#5
Banned
Thread Starter
Pretty close to what i've seen for a .2 GT3 non RS.
I usually dyno in din to avoid high numbers as its always really hot here in Florida. High humidity and heat would inflate numbers, either way all exhaust tests I do, I do same day, so the delta is all what matters to me. Absolute numbers don't tell much, unless you dyno all cars under the same dyno (which we do around here)
I usually dyno in din to avoid high numbers as its always really hot here in Florida. High humidity and heat would inflate numbers, either way all exhaust tests I do, I do same day, so the delta is all what matters to me. Absolute numbers don't tell much, unless you dyno all cars under the same dyno (which we do around here)
