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Toymods member
I supported Toymods
Location:
Rydalmere, NSW
Registered:
May 2002
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Gear used for Dyno run?
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Wed, 06 July 2005 10:41
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Just checking out my dyno sheet again, I noticed that my car was run in 3rd gear (or so it says). Now, going by these ratios:
1st -- 3.383:1
2nd -- 1.912:1
3rd -- 1.258:1
4th -- 0.918:1
5th -- 0.73?:1
... the dyno operator should use the ratio closest to the required 1:1 ratio for the most accurate power reading.  Based on this, mine should have been run in 4th gear. With a GT-Four gearbox, what gear is the correct one to use on the dyno?
Thanks in advance...
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Location:
brisbane
Registered:
December 2004
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 10:59
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most cars are 4th gear..
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 11:36
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the latest software from DYno Dynamics is funny - its a lot smarter than people give it credit!
Eg - your car was run in 3rd, being a 1.258:1 ratio, added to that you have a 4WD trasnfer case and TWO differentials, along with rather large diameter tyres.....
If you watched the screen as Dave was setting up each car for teh dyno run, he was inputting the type of car, gearbox etc etc before calibrating the dyno to do what i think was "equalise" the readings and create as level a playing field as possible.
Your dyno graph is signed, accredited and official as a comparison chart..... dont feel cheated mate 
Fwiw - mine was done in 3rd gear on the auto, and reached almost 215kph!!!! How's that for long ratios???
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Toymods member
I supported Toymods
Location:
Rydalmere, NSW
Registered:
May 2002
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 15:30
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Well I don't feel cheated at all, I was just getting curious as to why some people have a dyno run in 4th gear, and this was done in 3rd. Seemed a bit strange and for a minute I thought it was a typo... I think your answer is plausible Karl, although my tyres aren't that big - they're 20mm shorter in rolling diameter than stock RAV4 tyres/rims, even though they are 17's.
I gotta say it's some strange software.... but if it works..
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Location:
Brisbane
Registered:
February 2003
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 15:31
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Also to note at a twincam.org dyno day not that long ago there was a chaser that did back to back dyno runs in i think 3rd and 4th and there was less than 4kw difference in the power readout. i.e in terms of a power run, it doesnt make much difference.
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I supported Toymods
Location:
Brisbane
Registered:
September 2004
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 15:39
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So to dyno an auto car, they just leave overdrive off? Just curious how they do auto cars, never seen a dyno run in my life, much less an auto one 
(I'm a sheltered lad)
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Toymods member
I supported Toymods
Location:
Rydalmere, NSW
Registered:
May 2002
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 15:43
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They ususlly do auto's in Low gear...  but based on Witzl's results, I don't know if that's all that accurate anymore.
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I supported Toymods
Location:
Sydney
Registered:
August 2002
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 16:13
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mine was in 3rd gear
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Location:
Central Coast, NSW
Registered:
February 2005
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 22:31
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| Southo wrote on Thu, 07 July 2005 02:13 |
mine was in 3rd gear
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do they just accelerate really slowly to prevent kickdown?
cause if i have my auto's ECT-PWR on it has a real tendency to just kick down nice and early which I imagine would play havoc with a dyno reading
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Location:
Syndey
Registered:
December 2002
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Re: Gear used for Dyno run?
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Wed, 06 July 2005 22:56
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the new shootout software from DD has alot of different ramp rates for different types of cars etc, most 4cyl cars are run in 3rd, dyno dynamics state that a shootout run should start around 50km/h and finish around 150km/h which is usually 3rd gear,
as said before it makes very little difference to the power readings
Dale
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Location:
Melbourne
Registered:
May 2002
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 00:17
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Shouldnt you normally just use the gear with the ratio closest of 1:1
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 00:35
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| Fattony wrote on Thu, 07 July 2005 08:17 |
Shouldnt you normally just use the gear with the ratio closest of 1:1
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Not in the case of Shootout mode, you do the gear which best represents 50kph -> 150kph as thats the way it works it out most accurately.
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Location:
Canberra
Registered:
January 2005
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 04:41
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A good dyno won't read any difference in HP figures when run in different gears however torque will read very different. The lower the gear or the diff ratio the higher the torque figure. Running the car in as close to a 1:1 ratio as you can therefore gives you the most accurate torque reading, but it will always be very different to what the engine really has due to the torque multiplication through the diff.
Geoff
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Location:
Campbelltown
Registered:
November 2003
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 04:46
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awaits for jag to see this thread  though his not on the forums much anymore.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 04:58
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| GefGef wrote on Thu, 07 July 2005 12:41 |
Running the car in as close to a 1:1 ratio as you can therefore gives you the most accurate torque reading, but it will always be very different to what the engine really has due to the torque multiplication through the diff.
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Can people please let this 1:1 thing go? It's been explained above what is needed for Shootout mode.
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Location:
Syndey
Registered:
December 2002
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 05:04
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exactly,
if dyno dynamics stated that a 1:1 gear would be required for shootout then it would be used, they have stated the 50-150km/h is required and that is what is used,
when tuning a ecu it is different, most of the time i will use 4th gear as it is eaiser to calabrate the tacho with a 1:1 gear ratio but the ramp rate must be adjusted to allow the engine to rev up at the correct speed.
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Toymods member
I supported Toymods
Location:
Rydalmere, NSW
Registered:
May 2002
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 Re: Gear used for Dyno run?
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Thu, 07 July 2005 05:56
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Thanks muchly for your replies guys, very helpful.
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Location:
Canberra
Registered:
January 2005
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 10:39
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| justcallmefrank wrote on Thu, 07 July 2005 14:58 |
| GefGef wrote on Thu, 07 July 2005 12:41 |
Running the car in as close to a 1:1 ratio as you can therefore gives you the most accurate torque reading, but it will always be very different to what the engine really has due to the torque multiplication through the diff.
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Can people please let this 1:1 thing go? It's been explained above what is needed for Shootout mode.
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All I was trying to say is why you would ever worry about what the gear ratio was in the first place. Read the whole post nuffy!
This is only my opinion and I know its going to upset people but "shootout mode" is a bit of a joke. All it does is bring those dynos up to par with the better dynos out there!!!!!
Geoff
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Location:
Sydney
Registered:
January 2003
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 23:21
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They used 4th for mine, same last year.
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Location:
Perth
Registered:
October 2003
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Re: Gear used for Dyno run?
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Thu, 07 July 2005 23:32
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Can someone please explain 1:1 to me?
Is that like 1/1?
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Location:
Central Coast, NSW
Registered:
February 2005
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 00:02
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| Skip wrote on Fri, 08 July 2005 09:32 |
Can someone please explain 1:1 to me?
Is that like 1/1?
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All about ratios
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Location:
Perth
Registered:
October 2003
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 01:41
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OK Merudo I get it now, 1 Fish = 1 Atom.
But i still dont understand which way gives more pizza and why johal's car was dynoed in 3rd gear
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Location:
Central Coast, NSW
Registered:
February 2005
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 01:45
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| Skip wrote on Fri, 08 July 2005 11:41 |
OK Merudo I get it now, 1 Fish = 1 Atom.
But i still dont understand which way gives more pizza and why johal's car was dynoed in 3rd gear
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hahahahahaha
sorry, that was the most pointless link ever, wasnt it
Cheers
James
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 01:51
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| Skip wrote on Fri, 08 July 2005 09:41 |
But i still dont understand which way gives more pizza and why johal's car was dynoed in 3rd gear
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The incorrect way will give a non-standard size of pizza. Johal's car was done in 3rd as this was the gear that best represented the speed range required by Dyno Dynamics for them to create a standard sized pizza.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 01:53
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| GefGef wrote on Thu, 07 July 2005 18:39 |
This is only my opinion and I know its going to upset people but "shootout mode" is a bit of a joke. All it does is bring those dynos up to par with the better dynos out there!!!!!
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Yeah, because this is the reason the majority of the figures quoted are in Shootout mode. If you don't understand it thats fine, ignorance is bliss and all that jazz, but to say it's a joke clearly shows a lack of understanding about what they're setting out to achieve, thats the real joke.
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Location:
Perth
Registered:
October 2003
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 02:06
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| justcallmefrank wrote on Fri, 08 July 2005 09:51 |
| Skip wrote on Fri, 08 July 2005 09:41 |
But i still dont understand which way gives more pizza and why johal's car was dynoed in 3rd gear
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The incorrect way will give a non-standard size of pizza. Johal's car was done in 3rd as this was the gear that best represented the speed range required by Dyno Dynamics for them to create a standard sized pizza.
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So what you are telling me is in third gear the ratio would be something like dominos family : eagle boys family, but if johals car was dynoed in forth it would have been more like dominos family : eagle boys large, or have I got my pizzas the wrong way around?
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 02:08
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Don't eat at Eagle Boys usually, so you've lost me
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Location:
Canberra
Registered:
January 2005
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 06:41
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Yeah, you've got me. I don't have a clue. Can YOU explain it to me?
Tell me what is done differently when the dyno is used in shootout mode. Please tell me. What are they trying to achieve? Are you trying to say that figures quoted in shootout mode are somehow better or different to other modes. Should any of us not trust anyone with a different dyno that doesn't have shootout mode or vice versa?
Sorry, I'm a little ignorant and I really don't understand. Can your genius explain it to me? Some comparison to other reputable dynos and how they operate would also be useful.
Geoff
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Toymods Vice President
Location:
Sydney
Registered:
May 2002
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 07:05
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| GefGef wrote on Thu, 07 July 2005 20:39 |
| justcallmefrank wrote on Thu, 07 July 2005 14:58 |
| GefGef wrote on Thu, 07 July 2005 12:41 |
Running the car in as close to a 1:1 ratio as you can therefore gives you the most accurate torque reading, but it will always be very different to what the engine really has due to the torque multiplication through the diff.
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Can people please let this 1:1 thing go? It's been explained above what is needed for Shootout mode.
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All I was trying to say is why you would ever worry about what the gear ratio was in the first place. Read the whole post nuffy!
This is only my opinion and I know its going to upset people but "shootout mode" is a bit of a joke. All it does is bring those dynos up to par with the better dynos out there!!!!!
Geoff
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What are these better dyno's you're talking about and how do you define them as "better"?
The reason why the run is not necessarily done in a 1:1 gear is that the most accurate and repeatable results come from running the car such that maximum power occurs at roughly 140Km/h when using a dyno dynamics dyno. Now I'm sure you know a lot better than the designers of the machinery as to how it should best be used but I'll stick with what they have to say.
Dyno-Dynamics didn't become an industry standard because they were bad, strangley enough it tends to be the other way around. What the shoot out software does is make the dyno run in a consistent fashion that is not influenced by the operator. Thereby taking out the biggest cause of inacuracy in most measurements, the bloke running the tool.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 07:22
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| GefGef wrote on Fri, 08 July 2005 14:41 |
Tell me what is done differently when the dyno is used in shootout mode. Please tell me. What are they trying to achieve? Are you trying to say that figures quoted in shootout mode are somehow better or different to other modes. Should any of us not trust anyone with a different dyno that doesn't have shootout mode or vice versa?
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As you may or may not know, there are MANY uncontrollable factors that can affect a cars output power.
These include things like air pressure, air density, air temperature, etc etc.
Shootout Mode is Dyno Dynamics attempt to flatten out these variables.
It will mathematically change your output power depending on such values.
In reality your car will put out more power on a 10deg day than a 40deg day.
In theory, in Shootout Mode the cars output power should be identical, regardless of air temperature.
The problem with Shootout Mode is that its VERY dependant on the dyno operator. He can EASILY fudge figures to give a higher or lower reading, ESPECIALLY if he hasn't be trained, or he is not an accredited operator (Dyno Dynamics provides training so that people learn how to use this feature properly and effectively).
At a guess Shootout Mode got a VERY bad reputation to begin with as operators had no idea how to use it properly and huge figures were coming out everywhere.
If they incorrectly mount the airtemp sensor then the readout can go up or down quite dramatically.
[Updated on: Fri, 08 July 2005 07:23]
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Location:
Campbelltown
Registered:
November 2003
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 07:25
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in other words don't mount the temp sensor near the wall the exhaust is facing temp goes up so does power figure woot
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Location:
Canberra
Registered:
January 2005
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Re: Gear used for Dyno run?
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Fri, 08 July 2005 10:33
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| CrUZsida wrote on Fri, 08 July 2005 17:22 |
| GefGef wrote on Fri, 08 July 2005 14:41 |
Tell me what is done differently when the dyno is used in shootout mode. Please tell me. What are they trying to achieve? Are you trying to say that figures quoted in shootout mode are somehow better or different to other modes. Should any of us not trust anyone with a different dyno that doesn't have shootout mode or vice versa?
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As you may or may not know, there are MANY uncontrollable factors that can affect a cars output power.
These include things like air pressure, air density, air temperature, etc etc.
Shootout Mode is Dyno Dynamics attempt to flatten out these variables.
It will mathematically change your output power depending on such values.
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Give the man a prize.
Firstly, in my second post I said it was just my opinion, in my third I was being sarcastic. Secondly, I never said any particular type of dyno was bad. Thirdly, that type of dyno is not the best out there so I would hardly call them an industry standard, again, that is not saying that they are at all bad.
Atmospheric compensation for one has been around for a lot longer than when Dyno Dynamics started using it in shootout mode and yes there are many more factors that effect readouts. My OPINION on why they are a joke is the fact that the dodgy operators out there, through using this system, can fudge outputs. The better dynos for one, don't allow you the same capacity for dodginess. I have and have seen this proven time and time again. The reason I have such a strong OPINION on this is because in the recent past this sought of dodginess has directly involved and effected me and the work I was doing and did for over 10 years before I got out of the trade. For what its worth both Bosch and Dynamic Test Systems have dynos that are better than Dyno Dynamics.
By the way some of YOU need to get off this 1:1 thing. I know why you would or wouldn't worry about it. Read my post properly. If Dyno Dynamics want you to run at a particular speed good on em. I never said anything about it being wrong, not ideal or otherwise. Get over it, its just 'MY OPINION'.
Geoff
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Banned by his request
Location:
moved to tamworth
Registered:
July 2002
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Re: Gear used for Dyno run?
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Sat, 09 July 2005 05:07
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look at the time its 1 to 1 i need some lunch.
mick
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