Dyno Dynamics Shootout Mode – Fact Or Fiction.

[cuspub]

Seems amazing to me that people on this forum don't seem to understand that the simple premise behind what I opened this thread with was to suggest that irrespective of what Dyno Dynamics has done with their Shootout Mode package, it still leaves open the opportunity for the unscrupulous tuner to rip people off.

I am and was not casting any aspersions on the DD product whatsoever, rather it was a case of making it clear that when having one's car modified, we must always be vigilant.

That a number of different readings were achieved on the same dyno in a short space of time simply indicates what and how a dyno operator can fool people.

What Peter Luxon says about repeatability with the DD product is correct and I totally agree - if the playing field remains level.

The fact of the matter is that whether it's a Dynamic Test Systems, DynoLogic, Dyno Dynamics, or any other chassis dyno for the matter, if calibrated correctly - and if the playing field is level - they will all read within a few kilowatts.

As to your Turbo6man, well, you simply read-read it!

[CJF077]

I totally agree with APS on this one.. The variance on dyno results from different vendors and even tuning shops vary significantly, air temperature and the environment has to be exact to get as close to accurate figures as possible..

If you had the opportunity like i have had to have a look at APS's Dyno room including the air cooling setup, you too would believe that the setup they have is extremely spot on to give the most accurate results.

[cuspub]

Seems amazing to me that there is a misunderstand premise behind what I opened this thread to suggest. The fact is that I am stating that irrespective of what Dyno Dynamics has done with their Shootout Mode package, it still leaves open the opportunity for the unscrupulous tuner to rip people off.

I am not and was not casting any aspersions on the DD product whatsoever, rather it was a case of making it clear that when having one's car modified, we must always be vigilant.

That a number of different readings were achieved on the same dyno in a short space of time simply indicates what and how a dyno operator can fool people.

What Peter Luxon says about repeatability with the DD product is absolutely correct. I totally agree - if the playing field remains level.

The fact of the matter is that whether it's a Dynamic Test Systems, DynoLogic, Dyno Dynamics, or any other chassis dyno for the matter, if calibrated correctly - and if the playing field is level - they will all read within a few kilowatts.

As to your Turbo6man, well, you simply miss-read it!

[Mustang D]

Brian,

Your comments are reasonable, though there are other facts to consider.

We have tested a stock XR6T Falcon on four different Dyno Dynamics Dynamometers on the same day, with the tyre pressures set to a known value and tied down correctly on the dyno. Tested the vehicle in SHOOT 6 Mode (which is the correct mode for 6 cyl engines), the power variance between the lowest and the highest power figure was 2 kW – from 181 to 183 kW. This proves beyond doubt to me that the dynamometer and software is extremely accurate and consistent. The variable in most cases is the dyno operator, tyre pressures, method of vehicle restraint and cooling fans.

As for the APS dynamometer, it is calibrated monthly and is both accurate and consistent. I think many XR6T owners become confused because identical model cars should have similar power. The truth is we have seen and measured a variance of up to 18 kW between the highest and lowest power levels on a stock XR6T Falcon – 175 kW being the lowest to 193 kW highest and you can certainly feel the difference on the road.

The data that appears at the bottom of a Shootout power graph displays the environmental and Dyno Dynamics preset values recorded at the time of the power run. They are by no means identical unless of course all environmental conditions happened to be identical – which may or may not be the case. If you would like a thorough explanation of the data printed on the Shootout power graph, contact Dyno Dynamics as they are the manufacturer of the dynamometer and software, therefore they are best qualified to answer your questions. It is not prudent to be critical of a system if you do not have total technical understanding of the software. This is the software and dynamometer utilized at all major dynamometer competitions including Summer Nats. Whilst Dyno Dynamics has been manufacturing dynamometers for 20 years and are the industry leaders in their field through innovative engineering, it is no surprise that they are a big target for young dyno companies attempting to achieve market share.

I find it amusing that the person who started this thread happens to be a representative of a dynamometer manufacturer who is in opposition to Dyno Dynamics. It would be more professional if the author would be upfront and state who he is and whom he represents when making comments about a product or company on a public forum. I could say more though this is not the right forum to do so.

Chassis and engine dynamometers are excellent tuning tools in the right hands and I assure you that we do all in our power to measure and record actual power levels of the car in question. Whilst this may be good marketing as you say, it is also the truth – and there’s nothing more powerful.

Regardless of dynamometer brand, we should all remember it is a measuring tool. When engine enhancements are performed, it is vital to compare before and after dynamometer tests to verify the performance gain or loss across the entire power curve. Bottom line is that you need to be dealing with a reputable and honest operation, not Freddy from Ripsville. Like every industry, dyno operators range from the ordinary to the excellent. The challenge is to investigate and find a good operator in your local area.

I hope this helps.

I don't think the original author was disputing that you wouldnt get repeatable results from 4 different dyno's. What he brought to light was the fact that when the faster ramp rates were used, the displayed power seems to be being "bumped". Sure, Shoot81 or whatever is meant for

V8 Forced Induction, not a 6 Cyl, but at the end of the day, how does the dyno know that it now has a 6 cyl sitting on it and not a V8, should it matter?

I think us as punters who go to the Summernats or Holden/Ford show and see twin turbo V8's producing 1000hp at the wheels will now be very sceptical about these numbers as if you go by the example, the power reading could be fudged by at least 15%, real honest.

[Guest 56Mainline]

Had my XR6T run on a dyno dynamics unit in Shootout modes 6, 8, & 8.1.

Peak power results were 276, 278, 279.4 rwkw. Not much difference there!

The tuner also said that there wouldn't be, but I had to see for myself, & he then had to prove his point!

Should have also seen the same result in Shootout 4 mode, but potential for too much strain on the car.

That's my experience anyways.

[bcl]

APS,

Thank you for your comments.

Firstly, I am not involved in any dispute or argument with regards to different dyno types. Nor do I question or dispute the validity of your results, nor do I represent any supplier. I do have APS equipment, as I have other supplier’s equipment on my cars.

However, as a consumer myself and other people want to more clearly understand information that you and other suppliers present to us. I don’t believe that the original observations were clearly addressed in your reply.

My comments to your reply:

The data that appears at the bottom of a Shootout power graph displays the environmental and Dyno Dynamics preset values recorded at the time of the power run They are by no means identical….

True. Values such as IT (inlet temp), RT (room temp), RH (relative humidity), RP (barometric pressure) etc will vary according to the site where the run is conducted.

I was at the C&V dyno day, which I enjoyed very much, and David pointed out that all runs should use the same CK factor, for consistency, and which he indicated pointed to the shoot mode type used…. If that’s true I would expect to see the same CK value on each graph.

If you would like a thorough explanation of the data printed on the Shootout power graph, contact Dyno Dynamics as they are the manufacturer of the dynamometer and software, therefore they are best qualified to answer your questions. It is not prudent to be critical of a system if you do not have total technical understanding of the software.

I have taken your advice, and contacted Dyno Dynamics (spoke to Harry) this morning for further information not available on their web site.

I was told the following:

1. Using the same shoot mode type you should get the same results on different dynos …. No problems with this…. Should be consistent results. So Shoot 6 on one dyno should yield the same results as Shoot 6 on any other dyno. So Shoot 8 on one dyno should yield the same results as Shoot 8 on any other dyno.

2. Our XR6 turbos should be using Shoot 6 (turbos and non-turbo both use shoot 6)

3. If you do use shootout mode the published graph should say the shootout mode type used e.g Shoot 6. Clearly, Dyno Dynamics don’t want consumers to be misled.

4. Shoot 8 will give different results to shoot 6, and the correct mode should be used for the vehicle. I quoted to him the different results quoted as at the start of this thread I.e 288kw shoot 6, 305kw shoot 8, 317kw shoot81, and the reply was “what do you expect, they are using different inertia values”. ……. Yet we did see little difference in the stock vehicle (56mainline)

5. In regard to CK he did not know what is meant, but could get back to me if required…I left it there.

6. Normal users have green print on the bottom of the page; scrutineers have blue colour

Refer http://www.dyno.com.au/shootout.htm for further information.

In conclusion the Dyno Dynamics reply indicated that what was stated at the start of this thread was correct, in respect to the fact that all shootout mode tests are NOT the same.

THE SHOUTOUT MODE TYPE THAT IS USED MUST BE CLEARLY SPECIFIED. That is, just saying that shootout mode is used is not enough.

As a group, based on the advice I have today, is that if shootout mode is to be used, we should ensure that Shoot 6 mode is used for all dyno runs used on a Dyno Dynamics dyno, and that the operator print that Shoot 6 has been used, especially if the car is modified. Only then will we have a level playing field, and have a better idea where we stand.

I hope this helps to clarify the matter.

Brian

[hypnodoc]

A workman is only as good as his tools, or in the case of squandering plenty od mullah chasing kWs. Tools are only as good as the workman. I'll take my reading from the shove in the back when accelerating from now on

[Guest 56Mainline]

great post Brian.

[Mustang D]

I have taken your advice, and contacted Dyno Dynamics (spoke to Harry) this morning for further information not available on their web site.

I was told the following:

1. Using the same shoot mode type you should get the same results on different dynos …. No problems with this…. Should be consistent results. So Shoot 6 on one dyno should yield the same results as Shoot 6 on any other dyno. So Shoot 8 on one dyno should yield the same results as Shoot 8 on any other dyno.

2. Our XR6 turbos should be using Shoot 6 (turbos and non-turbo both use shoot 6)

3. If you do use shootout mode the published graph should say the shootout mode type used e.g Shoot 6. Clearly, Dyno Dynamics don’t want consumers to be misled.

4. Shoot 8 will give different results to shoot 6, and the correct mode should be used for the vehicle. I quoted to him the different results quoted as at the start of this thread I.e 288kw shoot 6, 305kw shoot 8, 317kw shoot81, and the reply was “what do you expect, they are using different inertia values”.    ……. Yet we did see little difference in the stock vehicle (56mainline)

5. In regard to CK he did not know what is meant, but could get back to me if required…I left it there.

6. Normal users have green print on the bottom of the page; scrutineers have blue colour

Harry, (on behalf of Dyno Dynamics, as he works for them) has now stated that the difference between 3 runs with different Shootout Modes on the same vehicle can be put down to Inertia.

Quote “what do you expect, they are using different inertia”.

The inertia he would be referring to is Dyno Inertia and Vehicle Inertia.

The Dyno Inertia, as stated on their website is 2.59k/m^2 (single retarder), this can be acurately measured as each component in the dyno can be broken down to individual components and their respective inertia calculated, then all added together to get 2.59kg/m^2. Once the inertia is known, you can then work out how much Torque it takes to accelerate the rotating dyno components at any given Ramp Rate (Angular Acceleration).

For eg. Using 2.59kg/m^2 at a ramp rate of say 10klm/h/sec, (this is you car accelerating at a rate of 10klm/h every second on the dyno) this equates to 66.31Nm or 48.91ft/lbs of torque. This means that 66.31nm is being added (in the software) to the measured torque at the Load Cell (this is the component that measures how much torque is being produced on a Chassis or Engine Dyno).

If you use a Ramp Rate half as slow, ie 5klm/h/sec, there would only be 33.155Nm being factored in, and if you use a Ramp Rate of 20klm/h/sec then the inertia is now 132.62NM (Ramp Rate 20 was the rate used on the APS BA Turbo at the Melbourne Expensive Daewoo Ford Show, clearly states this on the Dyno Printout).

There is nothing wrong with applying Dyno Inertia as the car has to make the torque to accelerate the rollers at any given ramp rate. On most vehicles, you can change the ramp rate from a very slow to reasonably fast and the power at the wheels should be very close, this is because it has appropriate Dyno Inertia. Once you try to ramp a vehicle on a dyno faster than it actually could accelerate on the road, the measured power will start to fall away as you are no longer measuring Brake Horsepower, this is easily seen on turbo vehicles as a drop in boost produced, as in the example vehicle in the thread starter, but, the vehicle in question somehow made more power?

The other factor that will then be used to somehow explain the 30KW extra is Vehicle Inertia. Vehicle inertia can be meaured as such, perform a graph at any given ramp rate, see at what road speed the vehicle made its maximum power, then manually hold the vehicle at full throttle at that road speed momentarily and compare the difference, the manually held speed reading will be higher as inertia is only applicable when acceleration (graphing) is being undertaken, the difference is vehicle inertia. On some cars, vehicle inertia is very small, ie rear engined race cars with integral gearbox/differential units with magnesium race wheels, other vehicles such as 4WD’s have much more vehicle inertia as the single biggest contributing factor with any inertia is Diameter, things like tailshafts and axles don’t produce signicant amounts of inertia.

The question that comes to mind then is, why should an XR6 Turbo use a different ramp rate (or Shootout Mode) to an XR8, as the drivetrain inertia difference between the 2 cars would be bearly measurable, the only difference being 2 extra bigends and the extra crank material, on again, at the back wheels, bearly measurable. The next question then is, why should a Supercharged XR8 have to use Shoot81, as clearly the drivetrain inertia would not be any different from a N/A XR8 other than a supercharger belt and pulley, does this equate to 12Kw, I don’t think so, remember we are talking about inertia here and not power required to turn a supercharger.

What these different Shootout modes clearly have are some sort of fudge factor the faster the ramp rate, this then poses the problem, at a local worshop dyno day where someone is going for outright power hero wank status, the person who has a 6cyl vehicle will be clearly disadvantaged against someone who has a V8 or Supercharged V8, think about this because alot of your XR6 Turbo’s can quite easily make more power than an old 5 litre Late model camira with one of those centrifigul blower kits, but you’ll be very disadvantaged because you’ll have to use Shoot6.

Just my thoughts, flame away.