Dyno Dynamics rolling road, accurate?
31-03-2009, 09:05 AM
#81
Interesting topic. 
IMO Gary's Dyno use and knowledge is impecable as are his tuning skills so I will take his readings as being as scientific a test as we can get for free on a mere forum and would hope you all appreciate him using up his valuable time to create and collaborate the information for us.
IMO Gary's Dyno use and knowledge is impecable as are his tuning skills so I will take his readings as being as scientific a test as we can get for free on a mere forum and would hope you all appreciate him using up his valuable time to create and collaborate the information for us.
31-03-2009, 12:54 PM
#82
10K+ Poster!!
Alex
31-03-2009, 01:53 PM
#84
But don't let that concept ruin the idea of Dyno usage, there are some of us that try our very best for consistency.
Others have managed to get themselves in the shit in the past with poor procedures, then it's hard to back-pedal. Speaking for ourselves, we started as we intended to go on.
31-03-2009, 02:03 PM
#85
So a great set up and dyagnostic tool with an estimate of hp if you use the same proceedure at the same place etc ,tbh what elso would anyone want defo not pub figures lol 
i think most see the figuires as is and get upset when they dont get what they want lol,just put it on the black stuff and hammer it lol ass dyno wins again lol
i think most see the figuires as is and get upset when they dont get what they want lol,just put it on the black stuff and hammer it lol ass dyno wins again lol
31-03-2009, 02:12 PM
#86
So a great set up and dyagnostic tool with an estimate of hp if you use the same proceedure at the same place etc ,tbh what elso would anyone want defo not pub figures lol i think most see the figuires as is and get upset when they dont get what they want lol,just put it on the black stuff and hammer it lol ass dyno wins again lol
i think most see the figuires as is and get upset when they dont get what they want lol,just put it on the black stuff and hammer it lol ass dyno wins again lolThis is why I have always flown the flag for Dyno-tuning, because how else can you truly know where the OPTIMUM timing values are, for example. Also, there are some things that you could never gauge improvements of on the road, such as manifolds and possibly even cams, but by overlaying RELIABLE graphs, the differences can be properly measured.
If I have time, when I finally get on to mapping mine, I will try and put some data on my thread.
31-03-2009, 03:38 PM
#87
PassionFord Post Whore!!
Yes, of course.
But don't let that concept ruin the idea of Dyno usage, there are some of us that try our very best for consistency.
Others have managed to get themselves in the shit in the past with poor procedures, then it's hard to back-pedal. Speaking for ourselves, we started as we intended to go on.
But don't let that concept ruin the idea of Dyno usage, there are some of us that try our very best for consistency.
Others have managed to get themselves in the shit in the past with poor procedures, then it's hard to back-pedal. Speaking for ourselves, we started as we intended to go on.
I know what you meant Christian, the problem is many people band round the hype that the Dyno Dynamics Rollers are the most accurate out there but the reality is they arent any more accurate that most others, I do believe there is a question mark over the issue of transmission losses which means flywheel figures greatly differ from other set ups because they are calculated not measured.
This coupled with some operators saying you do the run in 3rd, others 4th and some 5th and you have to pump the tyres up to some daft pressure like 50psi, then you have to be in this mode or another mode..... none of this gives confidence.
Especially when you keep hearing something is the most accurate thing in the world and then you run your own car on one and the figure is wildly off the mark you loose all faith in the kit as well as the operator
I know from my own experiences with my RS500 on G-Forces dyno some years ago when the car would not make anywhere near the boost it did on the road and only made something in the region of 260bhp at the flywheel
Now as we all know an RS500 running 23psi of boost on the road is going to make more power than that, but it would only made 19psi on the rollers, but even then a T4 whistling along at 19psi should have made more than 260bhp at the fly.
So it made the whole thing a joke, needless to say I would never trust a Dyno Dynamics rolling road to measure power.
Its a shame dim guys are fooking it up for the good guys.
31-03-2009, 04:03 PM
#88
Neil, that precise example of the RS500 at G-Force did what it did because they used the wrong dyno mode. The ramp-rate was WAY too fast and consequently the run was over VERY quickly and with much less boost than it should run.
As for tyre-pressures, Dyno Dynamics Shootout criteria does state 50psi for measured runs. We don't always do this, purely because the difference isn't very much, infact there can be more instability in readings by using sticky tyres (which we recommend against on the Dyno due to high heat build-up).
DD have always recommended 3rd gear for most 4/5 speed transmissions, which we mostly adhere to. There have been less than a handful of cars that for whatever reason weren't run in 3rd. But really not that many. That said, there are ALOT of tuners out there that have bought a modern Dyno, but are unwilling to be shown a modern way to use it and use their old methods. It's that I can't understand.
As for tyre-pressures, Dyno Dynamics Shootout criteria does state 50psi for measured runs. We don't always do this, purely because the difference isn't very much, infact there can be more instability in readings by using sticky tyres (which we recommend against on the Dyno due to high heat build-up).
DD have always recommended 3rd gear for most 4/5 speed transmissions, which we mostly adhere to. There have been less than a handful of cars that for whatever reason weren't run in 3rd. But really not that many. That said, there are ALOT of tuners out there that have bought a modern Dyno, but are unwilling to be shown a modern way to use it and use their old methods. It's that I can't understand.
31-03-2009, 04:17 PM
#89
Your procedures seem to Mirror JKM's use of their DD rollers too, they dont like 888's for example for the reasons you give.
I have a lot of respect for how they run their Dyno, and their figures always seem to be realistic.
Good dyno operator is a useful asset to anyone interested in genunine development.
I have a lot of respect for how they run their Dyno, and their figures always seem to be realistic.
Good dyno operator is a useful asset to anyone interested in genunine development.
31-03-2009, 04:26 PM
#90
10K+ Poster!!
Some good points covered in this thread and tbh some I'd like to see some actual results for, Its good to see you do try your best to keep the rollers consistant.
I've only put one car on a set of DD rollers and tbh I don't think the operator really knew what they were talking about, ok they knew way more than I do on the subject but when you start asking questions and they have to refer to their handbook I felt a bit put off.
I've mainly used Track and Road now for setups and power runs and I feel that they to make sure that they keep their setup as consistant as possible like yourself even if they do things slightly different, such as using top gear for mapping in some cases. One thing is for sure and thats if Roush and other manufactures will bring stuff all the way over to them they obviously have a lot of faith in their setup which makes me wonder what is so different about running a car in different gears and how accurate are other rolling roads ?
I've only put one car on a set of DD rollers and tbh I don't think the operator really knew what they were talking about, ok they knew way more than I do on the subject but when you start asking questions and they have to refer to their handbook I felt a bit put off.
I've mainly used Track and Road now for setups and power runs and I feel that they to make sure that they keep their setup as consistant as possible like yourself even if they do things slightly different, such as using top gear for mapping in some cases. One thing is for sure and thats if Roush and other manufactures will bring stuff all the way over to them they obviously have a lot of faith in their setup which makes me wonder what is so different about running a car in different gears and how accurate are other rolling roads ?
31-03-2009, 04:32 PM
#91
....and similarly, we Dyno'd (and infact tweaked the map on) the Mosler Europe Race Car and have had 2 other Moslers on our Dyno too.
We also have plenty of relatively low powered (50-150bhp) race-cars on our books, who are scrabbing around for 2-3bhp here and there and we can document their gains/losses that accurately.
Aside from the general consensus that a Dyno is a bit 'hit-and-miss', we use it as an incredibly accurate tuning tool and couldn't be without it.
We also have plenty of relatively low powered (50-150bhp) race-cars on our books, who are scrabbing around for 2-3bhp here and there and we can document their gains/losses that accurately.
Aside from the general consensus that a Dyno is a bit 'hit-and-miss', we use it as an incredibly accurate tuning tool and couldn't be without it.
31-03-2009, 04:36 PM
#92
10K+ Poster!!
What you said about actually seeing the gains made by using different cams and timing by overlaying graphs for example is a very valid reason to keeping them consistant and really using a rolling road over mapping on the road, I can't see how you could perfect a car on the road in that sense, I have no doubt you could get it close but visually seeing the gains or maybe losses is hard to argue with and surely quicker to resolve
31-03-2009, 04:41 PM
#93
PassionFord Post Whore!!
Your procedures seem to Mirror JKM's use of their DD rollers too, they dont like 888's for example for the reasons you give.
I have a lot of respect for how they run their Dyno, and their figures always seem to be realistic.
Good dyno operator is a useful asset to anyone interested in genunine development.
I have a lot of respect for how they run their Dyno, and their figures always seem to be realistic.
Good dyno operator is a useful asset to anyone interested in genunine development.
Does that mean these figures are real as theres a few people out there say they cant be
Mark
31-03-2009, 04:41 PM
#94
Testing the future
What you said about actually seeing the gains made by using different cams and timing by overlaying graphs for example is a very valid reason to keeping them consistant and really using a rolling road over mapping on the road, I can't see how you could perfect a car on the road in that sense, I have no doubt you could get it close but visually seeing the gains or maybe losses is hard to argue with and surely quicker to resolve
31-03-2009, 04:47 PM
#95
10K+ Poster!!
there is such a thing as datalogging on the road that would allow the experienced mapper to also see such things. you can actually then compare real world acceleration data (provided the same stretch of road, at the same temperature, with the same wind direction etc etc is used). but that's another subject that we should not go into on this thread as it should stick to subject and turn out useful
I don't claim to be able to map, I just sit back and take in what I can get my head round.off topic though have you recently sent me a language cd ?
31-03-2009, 05:15 PM
#96
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I havent read the hole thread, but ive used mahal, (spellin police needed) thousands of times. And i think there the best to use. im even sure that most car manufactures ue them too.
There an issue with the evo and scooby boys, they seem to believe that only dyno dynamics will read the correct torque figure!! witch i think is bullshit!!!
We ran my bros evo 8 on dd rollers, and it produced 380 bhp 400 l/bs mahal rollers 400bhp 360 l/bs.
I can post the graphes, also dd graphes looks like a a scribble with a crayon lol.
There an issue with the evo and scooby boys, they seem to believe that only dyno dynamics will read the correct torque figure!! witch i think is bullshit!!!
We ran my bros evo 8 on dd rollers, and it produced 380 bhp 400 l/bs mahal rollers 400bhp 360 l/bs.
I can post the graphes, also dd graphes looks like a a scribble with a crayon lol.
31-03-2009, 05:24 PM
#97
20K+ Super Poster.
Yes it DID make a difference on the temp controlled one I use(non-DD), and it has enough mass to measure trans losses as well, doesn't use a disc supplied by makers!!
tabetha
tabetha
31-03-2009, 05:57 PM
#101
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31-03-2009, 10:06 PM
#111
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i didnt look at wheel figure but im sure because fly figure was higher in 4th than third so will wheel figure be as dyno doesnt know what gear was done in
31-03-2009, 10:39 PM
#114
So essentially, less than 2% difference then if this was on your 600bhp or so engine?
Did it manage to hold anymore boost in 4th that would account for some of that change as well did you notice? (would only neeed to be 1psi though of course so not easy to spot!)
Goes to show that if operated properly, it can be very similarly accurate in any gear that
Did it manage to hold anymore boost in 4th that would account for some of that change as well did you notice? (would only neeed to be 1psi though of course so not easy to spot!)
Goes to show that if operated properly, it can be very similarly accurate in any gear that
31-03-2009, 11:28 PM
#119
Okay - sped read the entire thread. The initial question that I picked up was that u are surprised that a rr would read diff power between running in different gears. Or 17's and 19's according to rod's question.
My (limited) understanding is that the faster the rollers turn (higher gear = more roller rpm, as do wheel size as do smaller ROLLER size) the lower force the retarder needs to apply to stabilize the roller rev (therefore the lower BHP it will determine the car is producing). Perhaps a calculation could be built into the RR software that would take that into account however it would have to be a relatively clever programme to take into account every bhp and every rpm of the roller accurately.
SO in raw terms, the faster the rollers turn the less effort the retarder needs to apply to stabilise the roller speed, therefore the less BHP the RR will decide the car is making. This is not due to transmission losses, it is due to roller losses...
The example I was shown of how this can be seen (in a more real world application) is this. A massive fan (just happened to be a RR fan) required 5kw to do 200 rpm, it required 15kw to do 400rpm. This shows that the losses are in the speed of the rollers themselves, and those losses increase with RPM. A rr operates in a similar fashion (power of engine to create x rpm of rollers) therefore in a similar fashion (again), the higher the RPM of the rollers the more resistance that the rollers themselves create, therefore the less effort required by the retarder to stabilize a set power of engine.
All rollers are good for is applying a consistant environment with which to simulate road conditions to look for faults or mapping, or to apply a consistant environment to test the impact of your modifications. The best RR and operators can re-create similar conditions each time, therefore can work out if mods were an improvement or not.
Needless to say a retarder can only apply X resistance (ie it has a limit, like a set of brakes do), so once you get to the point a car can apply more power than the retarder can, a rr will not be able to stabilise and therefore create an accurate reading. SO you go up a gear, where the losses created by higher roller speed mean that less effort is required by the retarder to stabilise the RPM, therefore the retarder READS less effort and says the car is less powerful. It is not just about stopping wheel slip on the rollers.
As said, software might be able to take care of that but it would need quite a complex set of ratios to apply and testing the accuracy would be difficult.
Thats my thoughts on it all and I am sure someone who builds RR and the software they use could put me a little straighter on that, but I think it is more accurate than most everything else written about RR in this thread.
Cheers and look forward to seeing how rod gets on on the rollers, not for the bhp, just for the madness of running up that much power in a static environment Best of luck.
RW
My (limited) understanding is that the faster the rollers turn (higher gear = more roller rpm, as do wheel size as do smaller ROLLER size) the lower force the retarder needs to apply to stabilize the roller rev (therefore the lower BHP it will determine the car is producing). Perhaps a calculation could be built into the RR software that would take that into account however it would have to be a relatively clever programme to take into account every bhp and every rpm of the roller accurately.
SO in raw terms, the faster the rollers turn the less effort the retarder needs to apply to stabilise the roller speed, therefore the less BHP the RR will decide the car is making. This is not due to transmission losses, it is due to roller losses...
The example I was shown of how this can be seen (in a more real world application) is this. A massive fan (just happened to be a RR fan) required 5kw to do 200 rpm, it required 15kw to do 400rpm. This shows that the losses are in the speed of the rollers themselves, and those losses increase with RPM. A rr operates in a similar fashion (power of engine to create x rpm of rollers) therefore in a similar fashion (again), the higher the RPM of the rollers the more resistance that the rollers themselves create, therefore the less effort required by the retarder to stabilize a set power of engine.
All rollers are good for is applying a consistant environment with which to simulate road conditions to look for faults or mapping, or to apply a consistant environment to test the impact of your modifications. The best RR and operators can re-create similar conditions each time, therefore can work out if mods were an improvement or not.
Needless to say a retarder can only apply X resistance (ie it has a limit, like a set of brakes do), so once you get to the point a car can apply more power than the retarder can, a rr will not be able to stabilise and therefore create an accurate reading. SO you go up a gear, where the losses created by higher roller speed mean that less effort is required by the retarder to stabilise the RPM, therefore the retarder READS less effort and says the car is less powerful. It is not just about stopping wheel slip on the rollers.
As said, software might be able to take care of that but it would need quite a complex set of ratios to apply and testing the accuracy would be difficult.
Thats my thoughts on it all and I am sure someone who builds RR and the software they use could put me a little straighter on that, but I think it is more accurate than most everything else written about RR in this thread.
Cheers and look forward to seeing how rod gets on on the rollers, not for the bhp, just for the madness of running up that much power in a static environment
Best of luck.RW
Last edited by Steven_RW; 31-03-2009 at 11:33 PM.