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-   -   Possibly fake dyno results (http://www.the370z.com/tuning/131925-possibly-fake-dyno-results.html)

DrBacon 09-05-2019 03:23 PM

Possibly fake dyno results
 
I'm curious, is it possible to fake dynojet results? From my 10 seconds of research it doesn't seem "easily" possible, however in this car group I'm apart of some member posted their seemingly legit looking dyno graph of 368whp/324wtq on a g37. The car only has an exhaust, intake and manifold on pump 92 fuel (you can see the mods listed at the very bottom of the picture). I just have a hard time honestly believing it, as that would be close to record breaking N/A builds with 1/5th the mods and wrong fuel.

https://scontent-sea1-1.xx.fbcdn.net...0b&oe=5E12B9D0

OptionZero 09-05-2019 03:35 PM

The mod list is manually input, so thats one area to easily fudge

but otherwise, dyno results can vary wildly based on temperature, the strength of the fan, and type of machine

That is an unusually high amount given the mod list and type of gas

I think that range is usually something you need header, E85 and cams to get to

DrBacon 09-05-2019 04:21 PM

It is also an automatic, so yeah I'm going to call ********. Now the question is, what would cause something like that? Theoretically what would happen if they did the pull in a gear above 1:1 (assuming speed limiter was removed of course).

phunk 09-05-2019 09:26 PM

DynoJet software does not allow you to alter the readings any other than choosing from 4 available correction factors, or to display uncorrected numbers.

The only ways I can think of to get the DynoJet to produce false high graphs would be to lighten the drums on an inertia model (which it is very unlikely anyone would do), or to artificially heat up the dyno's temp sensor so that it causes a higher air temperature correction (which would only work when displaying corrected graphs, but not when displaying uncorrected graphs).

Although, producing a fake DynoJet graph does not need to be done at the dyno itself. People will simply use image editing software.

Such as was done, poorly, to this one you posted. (Incorrect font on the vertical HP scale. Incorrect font and alignment on the power and torque peak values. Most cringe worthy: peak values do not match the graphs. Graph shows the torque exceeding 330, yet the peak value says 324. Graph shows the HP exceeding 370, reaching about 380, yet the peak value says 368.) This was a poorly executed dyno graph edit.

Spooler 09-05-2019 10:16 PM

Quote:

Originally Posted by phunk (Post 3876658)
DynoJet software does not allow you to alter the readings any other than choosing from 4 available correction factors, or to display uncorrected numbers.

The only ways I can think of to get the DynoJet to produce false high graphs would be to lighten the drums on an inertia model (which it is very unlikely anyone would do), or to artificially heat up the dyno's temp sensor so that it causes a higher air temperature correction (which would only work when displaying corrected graphs, but not when displaying uncorrected graphs).

Although, producing a fake DynoJet graph does not need to be done at the dyno itself. People will simply use image editing software.

Such as was done, poorly, to this one you posted. (Incorrect font on the vertical HP scale. Incorrect font and alignment on the power and torque peak values. Most cringe worthy: peak values do not match the graphs. Graph shows the torque exceeding 330, yet the peak value says 324. Graph shows the HP exceeding 370, reaching about 380, yet the peak value says 368.) This was a poorly executed dyno graph edit.

LOL, Yeap, I see what you are talking about. What an idiot.

phunk 09-05-2019 10:37 PM

Not that it even needs further analysis... but if you look deeper at the math.. take the 368.69hp at 7090rpm as the max value claims... Well, 368.69hp at 7090rpm would be 273.1 torque. The graph is mismatched and says it has over 290 torque there, which would be over 390whp.

Youd need to understand dyno graphs to produce a fake one that can fool someone who does understand them.

Spooler 09-05-2019 10:42 PM

Quote:

Originally Posted by phunk (Post 3876665)
Not that it even needs further analysis... but if you look deeper at the math.. take the 368.69hp at 7090rpm as the max value claims... Well, 368.69hp at 7090rpm would be 273.1 torque. The graph is mismatched and says it has over 290 torque there, which would be over 390whp.

Youd need to understand dyno graphs to produce a fake one that can fool someone who does understand them.

Forgot about that. The torque is a derived/calculated value from the Hp reading.

JARblue 09-06-2019 01:53 AM

The math doesn't lie. Cheers, phunk :tiphat:

jchammond 09-06-2019 02:18 AM

Quote:

Originally Posted by Spooler (Post 3876666)
Forgot about that. The torque is a derived/calculated value from the Hp reading.

Thought HP was calculated from a mathematical equation...like torque x rpm divided by 5252 :ugh2: or something similar :wtf2:

adamDFKC 09-06-2019 06:37 AM

It looks like if you just subtract 50 from each marker on the Y-axis you have the correct values. So peak torque at 4,790 RPM is actually around 285.

HP = TQ*RPM/5252.

So at 285 ft-lbs at 4790 RPM the HP should mathematically be at 260. With the Y-axis corrected 50 points lower, it looks like 260 matches the graph.

Peak horsepower looks to actually be 330 at 7090 RPM.

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seymore4 09-06-2019 10:00 AM

I've heard a lot of "stories" about PRE this is the icing on the cake

DrBacon 09-06-2019 03:25 PM

Quote:

Originally Posted by seymore4 (Post 3876741)
I've heard a lot of "stories" about PRE this is the icing on the cake

I've used PRE before and had planned on using them again (just for dyno pulls), but this along with sketchy things I've also heard I think I'm going to look else where for next time. I've spoken to the owner of the car who had the dyno done and I think I'm inclined to believe it wasn't her faking the graph. Not sure why PRE would want to fake dyno graphs, repeat business or maybe just to impress her? Not sure, don't really care either.

Quicksilvers 09-06-2019 11:08 PM

They can’t pull the wool over our heads this dyno graph has been altered. Amen Phunk!!

MZ DAIZY 09-07-2019 01:36 PM

Those numbers look like they were taken at the crank, not the wheels.

Whjaxn17 09-16-2019 09:32 AM

The font and spacing is different/offset also. Both numbers are doctored, but that torque number itself is by far the biggest giveaway.

Also, OP, would you care to disclose this group? I'm in a couple, but haven't seen this gem floating around.


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