Whats REALLY in a Dyno Number? (Is it real? Is it fake?)

[TheSVTKid]

So another random video figured you all might like....

After being asked this question like 358,584 times in the past 20 years....
"Why does ______'s dyno read high, and ______'s dyno read low"

I finally broke down and just explained ONE of the variables that cause this.
AND, hopefully, show people that the only way to get "real results"

IS, to make sure after every modification, and every tune.
You ALWAYS use the same dyno shop, same machine, etc.

At least THEN, you are eliminating ONE major variable.


Hope you enjoy!
Erik

 

[whitedevil95]

Good stuff.

 

[CobraBob]

Very interesting video. Saved for future reference.

 

[GNBRETT]

good stuff thanx

 

[PaxtonShelby]

Good stuff that many folks don't realize. Thanks for taking the time to share.

 

[04DeadShort]

interesting, thanks

 

[Blk91stang]

Good video although I wish you included some technical explanation behind it. What is that and why does it have such a big impact on the hp? How does the dyno manufacturer recommend it be installed and controlled?

 

[whitedevil95]

Good video although I wish you included some technical explanation behind it. What is that and why does it have such a big impact on the hp? How does the dyno manufacturer recommend it be installed and controlled?

Totally agree! I assumed it was something about the weather data. But yeah more info.


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[StrayBullitt]

Good video although I wish you included some technical explanation behind it. What is that and why does it have such a big impact on the hp? How does the dyno manufacturer recommend it be installed and controlled?

Agreed, interesting video, but as a viewer I would have appreciated it more without any of the the sarcastic ad lib. This is a topic I want as much straight forward factual info. as possible.

I have never operated a dyno, but what I am taking away from this video is that was the dyno jet's ambient temperature sensor they were messing with, and that input is important due to the machine applying correction to the numbers. There is more correction needed for a hot day vs a colder day, thus why they showed an increase in power once the tech breathed on the sensor to heat it, the dyno adjusted and applied more correction. I'm guessing dyno thought the Engine was breathing 98 degree ambient air when really it was around 75 ??

I would think a shop would not have that sensor hanging in direct sunlight, but you could see something like that possibly happening. Might be good idea as a customer to ask to see what the air temp reading is before making a pull to make sure it is accurate

 

[slow306stang]

My 2012 GT put down 655whp 627wtq on a dynojet. It has a d1sc wastegated at 11.6psi, full exhaust, e85, and all other supporting mods. I knew the tune was dead on, no boost leaks, ect. People with similar combos are making close to 750whp...

At the track it trapped 143.4mph with a 3650lb race weight. I no longer care about dyno numbers lol

 

[kwkshift]

I also like how everybody the dyno's their car was on a "conservative" dyno. Yet, everybody else's dyno is a "happy" dyno posting higher than "real" numbers.

 

[tones_RS3]

Good stuff.
I guess it's a good idea to ask where that controller box is located when getting your car dyno'ed. Whether it's in a controlled environment or not. Also, make sure that the SAE correction is at the same number.
Did not know any of these. Thanks for the info.

 

[03cobra#694]

Oh jeez, you can't see the objective here,

 

[92GreenGT]

I just use the dyno as a tuning tool to get the tune close then finish it up with some street tuning. Once it's safe and happy, the track becomes the real dyno for me.hehe

 

[Bandit5.4]

Best response I can give for why dyno numbers are meaningless: me vs t-trim LS3 vette. Both cars read 630rwhp on 2 different dynos.

 

[ibleedblue65]

Best response I can give for why dyno numbers are meaningless: me vs t-trim LS3 vette. Both cars read 630rwhp on 2 different dynos.

Eh. There's a lot more to it than that. That video doesn't really prove or disprove anything about dyno numbers. Power band and how the power is made plays a big factor. The vette probably makes 630 peak but I'm sure your car has a lot more under the curve.

 

[Bandit5.4]

True. I shouldn't have said "meaningless". You're right, they don't tell the whole story.

Sent from my SM-T813 using the svtperformance.com mobile app

 

[SVT-BansheeMan]

I just go to the track and get heartbreak slips. That's all i need to see.

 

[GT Premi]

Agreed, interesting video, but as a viewer I would have appreciated it more without any of the the sarcastic ad lib. This is a topic I want as much straight forward factual info. as possible.

I have never operated a dyno, but what I am taking away from this video is that was the dyno jet's ambient temperature sensor they were messing with, and that input is important due to the machine applying correction to the numbers. There is more correction needed for a hot day vs a colder day, thus why they showed an increase in power once the tech breathed on the sensor to heat it, the dyno adjusted and applied more correction. I'm guessing dyno thought the Engine was breathing 98 degree ambient air when really it was around 75 ??

I would think a shop would not have that sensor hanging in direct sunlight, but you could see something like that possibly happening. Might be good idea as a customer to ask to see what the air temp reading is before making a pull to make sure it is accurate

I'm not asking you specifically, but why not just hang that sensor in the intake housing when doing dyno runs?

Best response I can give for why dyno numbers are meaningless: me vs t-trim LS3 vette. Both cars read 630rwhp on 2 different dynos.

I would chalk that up more to the Corvette getting heat soaked or his boost went out of its efficiency range based on how you ran past him up top. The beginning of the race looked like what would be expected from two cars with the same power but different weight.

On the topic, I'm someone who actually prefers to see the STD numbers instead of SAE corrected. I want to know what my car actually made in those conditions, not what it would've made in ideal conditions. Also, messing around with that sensor is no more "faking" numbers than when guys ice their blowers. When I dyno'd my GT500 with the Ford Racing tune, it only put down between 620 and 630 WHP. The operator put bags of ice on the blower and waited a few minutes, then it put down 690. I never quote that number to anybody when discussing what my car makes. Quite honestly, after installing a VMP tune, I have no idea what it makes now. I just know it felt 100HP stronger than the Ford Racing tune, and that made me happy. The new tune actually felt like what I was expecting it to feel like with the Whipple 2.9 from the beginning. I haven't done any other power adders other than a SCJ monoblade, so I just conservatively guesstimate and tell people it's probably making somewhere around 660 at the wheels now. It's probably in reality making closer to 680WHP, especially with the amount of rotating mass I've taken out of the powertrain and drivetrain.

 

[StrayBullitt]

^. I would agree on knowing std numbers, but SAE corrected numbers are better for testing individual mods..you want that standard baseline.. and it allows you to be able to go to the dyno on a 90 degree day and expect the same outcome as if you went on a 70 degree day for example.

Also agree on the icing the blower, or intake, or spraying Nitrous across the intercooler... all that stuff, it is interesting though to see how it affects the numbers and knowing that you could do that stuff at the track and get a little more uumph... I'm Not a make a number guy on the dyno.. but if I'm running a 10.00 at the track, hell yeah I'm gonna ice whatever I can to try and get that 9.9