It's all good buddy. If you're ever up in MA I can strap you into our dyno. My car read 340whp there stock exhaust best pass.
Shootout mode would probably read in the 275 range on a dd. Super low
Since when does a Dyno Dynamics read low?
We seem to get an average of around 335 RWHP which is very much inline with dynojet's. So do the rest of the other tuners around the world except a few.
It's all got to do with the tension on the straps........ probably the single most annoying thing about the DD and the one thing the operators use to manipulate when they know they are going to be asked for the correction factors.
Wow, someone is pushing for it to be used. I am not alone!
They don't use it because it would set the ramp rate the same, it would make the correction factors appear and the dyno would actually be used correctly with some consistency added to the mix. They wouldn't want that would they now!
I think it's best people stick to dynojet's because it's a simple fact that the Dyno Dynamics is so badly abused.
Oh, and you can change the correction factors in shootout mode also. On the earlier versions the operator puts them in manually, on the later version there is a inbuilt weather station but you can over ride it.
You can put in a correction factor of 1.00 for one set of runs and then for the second set you can put in 1.05. So there would be a phase shift in the graph of exactly 5%. If a car made say 335hp with CR=1, it would make 351hp with CR=1.05
+16hp.... that's a remap..... give us your money!!
If the car is strapped hard the wheel has contact with both the front roller (the one that reads) and the rear stabalising roller. Strap the car loose and the car will climb the front roller and leave the rear one which will reduce the frictional losses = higher HP reading.
Want me to demonstrate with a video?
You cannot see the correction factors unless they are displayed. You cannot even tell if the same gear was used.
Infact, you can't tell anything!!
Strangely.... no one gives you any information no matter how hard you ask.
This is what I love about dynojet and their Winpep software.
You can tell what gear was used because you can bring up road speed. You can see the correction factor.
Infact.... I might just buy one.
email@example.com and if it is well done and educational I will put it up on the front page.
I could not agree more with your line of thinking, nothing frustrates me more than dyno dynamics dynos and trying to figure out the correction factors or whatever else might be going on.
I thought shootout mode was designed to resolve this issue but I guess not.
The dyno has an excellent retarder which allowed us to do alot of steady state calibration on race cars with aftermarket ECU's.
It is a good machine if used properly but we were not aware it was so badly abused when we purchased it.
The one thing that is there is the fact that everything is recorded and if the information is given up everyone gets caught. Alot of people get caught!
Shoot out mode would help matter alot because atleast the CF's are being displayed and all someone has to do is go online and check what the weather was at the nearest airport (if applicable) or nearest weather station. You KNOW when someone has cheated!
Strapping differences can also be caught out. Takes a keep eye though.
Will get a video done and send it over to you.
Numbers will be all over the place outside of shoot out mode and if correction factors are being set or cars being strapped. I have had conversations with some of the mentioned vendors and they do strap down real hard.
If I strap down an M3 real hard my figures are very much like that of Gintani.
Autowave...... I have seen dyno graphs from there including 500WHP E39 M5's which have basic upgrades. They really do add 20%! It doesn't really matter as long as they are consistent.
You know..... dyno's are just abused. Full Stop. It's happening too much now. Needs to stop.
We don't have this problem in the UK.
There is some good consistency over here between dyno's. Only if the weather conditions are quite different do the numbers vary because correction factors can only do som much with their 'assumptions'.
It's easy to get everyone to use the dyno in the same way. You know how powerful the forums can be..... just write an article and everyone will suddenly get into shape.
'dyno graphs published without correction factors should be considered scrap'
Standardise the gears used for M3's on different dyno's. Standardise whether or not the cars should or should not climb the front roller to eradicate strap tension issues.
You can get rid of the confusion.... it's easy. You'll go down in history for it and alot of tuners will pay you alot of respect (if that means anything to you). You have the power to do it.
We don't have this problem with E39 M5's for example accross the world even on different brand dyno's!
weather conditions change 1/4 mile times.....
Unless of course you take a control car everytime which standardises everything.
Best test for the road are in gear which removes lanuch variation + a standard control car everytime. Best way to measure performance.
The thing, I can't suddenly dial up different weather conditions on my keyboard. I can't suddenly make timeslips 20% faster with a keystroke.
I know dynojet has become the standard in the US and its consistency is definitely an advantage. Unfortunately the power figure it spits out is not based on science -- it is based on a legacy of fudge-factoring dating to the founder's belief that a 145hp 1985 Yamaha motorcycle should make 120rwhp: http://www.hotrod.com/thehistoryof/1..._creation.html
Physics calculations from vbox data indicates that the modern dynojet reads ~12% high -- something tuners down under have been saying for years...
If they do read thigh though, why is it dynojet readings almost always correlate to the accepted 15% drivetrain loss figures for manuals for example?
Sal, nice to see you over here as well. A video would be great for people like me with little brains ;-)
Also while we're on the topic of weather stations and correction factors. The day I had the car dynoed, outside ambient temp was around 32-33F. However, we dynoed inside their heated garage where the temp was much higher. I'm not sure how weather stations work, but if I used a handheld like a kessler and took a reading inside their shop vs outside, would the readings be different?