HOW REAL ARE DYNO NUMBERS? | Horsepower United

Ever wonder why some dyno's read "high" and others read "low" ?
Well, this is a quick and dirty video to help explain just ONE of the factors that can lead to this mystery.
Remember, if you really want to know the "gains" from a new modification, or a new tune or tuner. ALWAYS use the SAME dyno that all runs have been made on. (Sure you still have a few other variables to worry about) Since then you have at least eliminated THIS major variable.
Hope you enjoyed!
Erik
NOTE: Thanks to House of Boost, for letting me us their stuff.
www.houseofboost.com
NOTE 2: Thanks to Schoneck Composites for lending me this CTSV
www.schoneckcom...

[@tedcollins2331]

Great video Erik. Thanks for taking the time to put this together. I have always wondered the same but didn't take the time to get clarification. Still enjoying my white 2017 Mustang you guys did for me through Sarasota Ford. The only issue is that I have a permanent smile on my face that I cannot seem to get rid of.

[@erikradzins]

Ted Collins that's awesome! Those guys do a great job there!

[@camxiong]

Shouldn't the software be making corrections based on those readings, so that no matter the difference it gives a consistent readout?

[@dronexfun8469]

I love that Caddy. Thanks a million for sharing all that info man.

[@erikradzins]

Thanks man!!! :)

[@GregoryAsher]

Chad is a pro videographer.

[@stvkeith]

Good video Eric. One thing to mention is that you can right click on the graph display and choose to display CONDITIONS, which will show the pressure, temperature and humidity during that dyno run, and show the correction factor amount. That number is the multiplier to the actual measured HP that the correction factor will add (or subtract). If it says SAE=1.03, then the SAE correction factor is adding 3% to the uncorrected, measured power numbers. A lot of shops use the old STD correction factor from before 1990, because it can show higher numbers due to the old formula using different "standard values". That's one big thing to watch for.

[@erikradzins]

Correct..... I saw a shop posting a sheet the other day with 26.8% CF!

[@WingBreaker25]

I see that black Trans Am in the back! I'd recognize my car anywhere haha.

[@0x33_Uk]

Its always a good idea to give a customers dyno graph with the conditions of the run and correction factor %. That will weed out the bullshit fairly easy.

[@danniiliasoff2732]

Tryed that in Denmark. They messured 350bhp but the car only had 300. Torque 600 but the car had only 500🤮👎. So, be aware out there what you Pay for. Great video ✌️🙂

[@chaztitan6457]

that doesnt really matter when you tune the car. what ever error the dyno is giving you as long as its an consistant error. and you tune the car and you started with 350 and ended up with 375. then you got more. just like a math equation, drop out the constant and TADA!!! the real problem is when you compare different dyno's.

[@AB-80X]

What shop?

[@AB-80X]

Woah. Now we know how it would sound if Tom Lehrer was a car guy. Your voice sounds exactly like his😀 Good video. I have been trying to pound this stuff into peoples heads for years, but nobody listens.

[@KooKL4]

Eh, a dyno is a tool. Yeah you can compare numbers, yes you can see a percentage of overall gained power which really is nice; but too many people make too much of a stink when there are too many factors to weigh over something that (I believe) has the main purpose of simply to assist in tuning. To each their own.

[@erikradzins]

Agreeeeeeee

[@MrYukon04]

And this is why performance shops that have their Dyno days keeps the people coming back because they manipulate the numbers like this and make him very high. My car at one point was making only 550whp I love racing those guys that came from the big shop saying they made 700whp and then I'd walk all over them and they didn't understand why and I said because my car was tuned properly not to make high Dyno numbers I like track numbers I don't race my Dyno sheet lol

[@erikradzins]

Exactly!

[@ALDPT]

You just kill many dyno shops and i like it because many are fake

[@Anarchy-Is-Liberty]

I guess I don't understand how a "dyno shop" would benefit by telling someone their car is making more or less horsepower than it actually is. I pull my car in, they run the test, I get the results, I leave, how in the fuck? Are you saying they're trying to sell more parts to these people or something, so they lie about power figures?

[@6ft3soldier]

Ok i just put my car on the dyno today 9/20/2021 it's a mustang and there dyno jet said I have 658hp 522tq Now my boy mustang went to a different dyno and his numbers were 684 hp 639 tq tell me why his numbers are much higher. When we race it's not even close when I beat him IM PUZZLED??

[@ALDPT]

there is no dynojet working 100% the best way is to take your and try it on road

[@Dave-so7sf]

I hate dynos for measuring power just tune the thing and let me go see what it traps! So many tuners out there trying to impress there customers and generate more customers by inflated numbers. I’ve decided next time I go to the dyno I’m going to crumble up the results the second it’s handed to me a throw it in the trash.

[@businessmanph]

Sounds like a raging title wave

[@doubl33Ace]

Love the video, subscribed. Keep it up.

[@leekouvlogzs]

good real talk on dyno

[@turbovolvos40]

Why not ask for the uncorrected and corrected numbers?

[@soupboneken9330]

thx....i learn somethings today

[@SkylineR34EvoX]

Great information you are providing in this video but I wish you would have elaborated more on what was going on. I am assuming that the SAE correction factor is based on a specific ambient temperature (and other environmental variables), say 75F, and by dynoing a car at say 65F where the engine sees more mass flow, the CF produces a lower corrected hp number? How does the smoothing factor play a role in hp numbers?

[@erikradzins]

The more "smoothing" that is applied the lower the numbers. But its also key to use the same smoothing on each graph, that way the "gain" can be the same. You also want to make sure the dyno operator has all of the grounds hooked up correctly on the dyno, to allow for a very "clean" and smooth signal to the Dyno computer. This will make for better and more consistent results.

[@AB-coyote]

@@erikradzins How big is the power difference between smoothing 3 vs 5 using the SAE correction? Generally speaking of course. For something like a boosted Coyote Mustang that is expected to hit the 600 RWHP mark.

[@rpmautoreviews9249]

I had my dyno but they didn't have a fan in front... as I see others don't either. how much would that affect the results ? I don't know if he turned off traction control or not. Oh, it was a dynocom, which guy said it's similar to mustang dyno and says its more accurate than others... ?

[@erikradzins]

1) a fan is a must must must. If there is no fan, you don't have an intercooler, you have a "heat sink" since there would be no airflow. 2) have to fully disable TC by usually pulling fuses. 3) Dynos aren't meant to measure power, but gains, or to be used as tuning tools.

[@rpmautoreviews9249]

@@erikradzins o.k. so my guy didn't have a fan.. I see others that don't, so why wouldn't they ? Here's my video I did on my dyno.. and my numbers for my stinger gt are 300 whp and 383 lb.ft. my torque is great numbers, but whp is lower than others I've seen. kzbin.info/www/bejne/ZpCvqZmCg5eKrKM

[@bobbymadjidi1592]

My car had a dyno in CA pumping 91 and got 475hp with sae. In TX I’m pumping 93 and it got 398hp with std. Why so stark? Does it even matter?

[@Venomxjjb]

Id love to watch some of the performance upgrade companies run a dyno. K&N for example claiming 15-20HP bump from an intake swap, when in actuality its more like 5-10 tops because they did something between the dyno runs. Maybe next video? lol

[@erikradzins]

Great Ideas!!!!

[@codygreen3096]

Cold air intake will give you nothing lol same with that stupid throttle spacer body kit and even those hand held tuners are garbage too !

[@heith85]

Wow not much a price difference for stat or holidays for Dyno runs. I don't think in Canada any auto shop is open on a Sunday let alone a holiday.

[@95TurboCivic]

Lol just change the power multiplier like everyone else does

[@arronlowley5659]

Hi, ive come to this video to ask for some feedback, so, last year in october my car was tuned, 440bhp 413ibft it made, temp was 68f and humidity was 45%, this was done in 5th gear. fast forward to this year, had the car on another dyno, this time it was run in 4th gear when i had requested 5th gear and the results were quite shocking, this time humidity was 70% and the air temp was 50f, the car only made 337whp/396bhp and 396ibft of torque, so a difference of 44bhp and 17ibft, does this seem right? can a different gear really affect it that much.

[@torbenalstrup3902]

A bit late for answering, but it is pretty simple. The dyno was not set up (calibrated ) for the difference in wheel speed. We see this all the time, so you are not alone. Like was mentioned, and proved once again, in this video, proper calibration is paramount for getting proper and accurate numbers. It is basicly for the very same reasons that many people do not trust a chassis- or engine dyno, because you can get high- or low numbers dependant on how you set the software up. Some dyno´s arent even calibrated after installation and show numbers that are totally off, like, completely off. If you come to such a dyno Kook´s approach as above is correct. you can only use it to see if your power increases or decreases with what you are doing. This issue is especially prone with Mustang dyno´s I´m not sure if they have a tendency to go out of calibration or they just don´t get calibrated in the first place. I have seen a 11 sec. Charger make a whopping 285 whp (!) The comment from the operator was, Yeah thats about right. ´Nuf said.

[@410cultivar]

Basicly him heatimg up that sensor with his breath made the dyno think,it was hotter out.....but that car ran off what actual temp was(cooler than breath) so the dyno thinks the car is that much more powerful. When he cooled,it down the dyno again plans for a certain math off that cooler temp. But again the car is running at a diffrent temp....so it made less Is that right?

[@davidhajes1003]

it is all about air density - cool air = more air into engine. you have usually over 40C entering engine and full load even more...since dyno computer is based on some calcultations of power...you can fool it by false temperature...if you check out any dyno graph, they usually have 20C IAT and some even are so stupid and show ambient temp 40C...if you have 40C ambient, you cannot have 20C air entering engine....unless you have IC with liquid oxygen

[@yudaresigama4209]

Every great educational video always have low view count

[@erikradzins]

Ya it sucks. Now if I smashed a car or blew something up it would get millions of views lol

[@ashleyhaine3361]

Thank you my brother x

[@JUNKYARDGTO]

Trust me im not worryed about loosing 100 hp on the dyno 🤣

[@Bawla187]

Great video 👍🏿

[@JordieG8]

6 years later and this problem is even worse. Companies toying with numbers to make their products stand out from the next guy, and the sad part is people believe it. The Subaru world is terrible for this.

[@erikradzins]

Really? I had no idea people are still doing this!!!! Wild!

[@JordieG8]

@@erikradzinsyeah, it’s sad. The problem is people are so utterly uneducated that they believe and promote these companies.

[@seanyworny104]

Love the blowers

[@6ft3soldier]

Ok i just put my car on the dyno today 9/20/2021 it's a mustang and there dyno jet said I have 658hp 522tq Now my boy mustang went to a different dyno and his numbers were 684 hp 639 tq tell me why his numbers are much higher. When we race it's not even close when I beat him IM PUZZLED??

[@erikradzins]

Different dynos, different readings. Hence why a dyno is really just a tuning tool, and the only way you can know your gains is to use the same dyno, and preferably on the same day.

[@joes.7536]

There great tools. Street tuning is dangerous at high power levels. I have a turbo Volkswagen. Sure it's a quick daily sedan and fun as hell to drive but it's definitely not a fast car. I pretty much have every single bolt on and rhe best tuning option for a stock Turbo. I am Limited in power due to the size of my Turbo. Although the tiny turbo spools instantly and makes it fun to daily. There was a guy at water fast with almost the same setup as me. Except he had a two and a half inch exhaust and I have a full 3 in. He was claiming some insane Dyno numbers. Like 279 hp to the wheels. That is just impossible with the stock Turbo. Even with race gas in all the timing in the world you're not going to crack 250. No it's just pretty annoying. He was claiming High 11-second passes. And that was even more laughable. My very best pass on a cool night like perfect pass was a 13.7. and my car is built with better Parts with lighter wheels and better tires. And this particular setup doesn't even create a high-horsepower number. It Creates a high-torque number. Turbo runs out of breath past 5000 RPMs.

[@SupeRTalorgang]

Got my car Dyno Tuned and i think somethings off, can you help??

[@erikradzins]

I likely can not. :(

[@smokeymcdrifts5442]

I guess its an ambient air temp sensor?

[@erikradzins]

Temp, Pressure, Humidity

[@delanogouldbourne7215]

If you show the runs uncorrected then the numbers will be consistent

[@erikradzins]

Exactly. My point is that people don't do that. ;)

[@mociczyczki]

So this dyno has not aLgoryth that corrects the infuence of temperaturę on the results 👌🏻

[@jdigitalseven7]

Should only dyno with hood down. Unrealistic to do it with hood up.

[@AB-80X]

That really depends on the setup and car. Some cars take air in in a way that makes no difference. However, what can make a difference in that case is the difference in airflow over the radiator. Some shops with smaller fans will actually get better flow and more realistic radiator airflow with bonnet up vs. down. I run hood down at the facility where I rent my dyno time as they have a fully controlled cell with both temp and air movement control over the entire car. It's basically a wind tunnel with a dyno. However, at another facility I use on rare occasions, I leave it open. I have checked my engine compartment temps and radiator temps during drives, and if I leave the bonnet down, it gets way hotter in there and the radiator loses its ability to properly cool. However, the air is still taken from the outside, so little to no difference there. In short, there are many variables, and unless you have a real test cell, you will probably get more realistic results with bonnet up. You need to be much more aware of how tight you strap down and where on the rollers the car sit. I can fake numbers just by moving the car 3-4 cm on the rollers, strapping it too tight or playing with tyre pressures.

[@RobertoGonzalez-cm5vb]

💪👍🙏

[@erikradzins]

Thank you! :)

[@stangtrax]

9:20 this this this, what is the name of this?

[@erikradzins]

thats the "weather station" that calculates the correction factor for the dyno. Its its not in the correct location, then basically the dyno numbers are whack.

[@reinaldocruz4452]

Erik Radzins what is the correct location for this this

[@mira5L]

What box/sensor is that?

[@JaegerWrenching]

That's the "weather" sensor. It looks at Air Temp, Air pressure, and Humidity. All of those affect power quite a bit as we saw.. They showed mainly how much Air temp affects power. But humidity can change it a lot as well which is why his breathing on it changed it. He heated up and added humidity in the "air" by doing that. It's the same reason we use intercoolers on cars. Colder air is more dense and will result in the ability to burn more fuel which makes more power. In a perfect world this sensor would be right before the vehicle's intake right by the air filter. You'd get almost perfect data.

[@griplimit]

This is why I dislike SAE correction.

[@_i-kr6eg]

Nothing new here mate a dyno is a a mechine too test and can also altere the power figure by confusing the sensor the dyno itself has to check for air temperature and humidity (list goes on ) because that cars ecu/ sensors on the engine can be old or not read true values. . If you want to know true power figures maybe get your engine put on a ENGINE DYNO. Then you'll know what sort of power you are actually making or going to make at the wheels

[@erikradzins]

I prefer to weight the car (with driver) and go to the track. The MPH tells all. :)

[@_i-kr6eg]

@@erikradzinshow so if on the track lots of difference in temperature ,track surface, tyres /tyre pressures, suspension setup .

[@erikradzins]

I am not talking about ET... I am talking MPH. Even if you go from a rolling start, the MPH is usually within 4-6mph of what it would be without the rolling start. (due to the lack of mechanical advantage and TQ mutiplication).... take a decently set up car, with a decent launch, and a decent run... the MPH will tell you all you need to know. (and a good scale, and a weather app on your phone)

[@_i-kr6eg]

@@erikradzins mate it makes no difference the mph because you can go or do a good ET with a low mph or even the other way around. Ive seen car run 145 mph at 10.5 . So mph means nothing . If you can get the power down and all the other factors sort of right then your wasting your time and money. Time for a new hobby or workshop/tuner dyno guy .

[@erikradzins]

Dyno HP Numbers = Weight and Track MPH::::: That is how you do a comparison. IE: if a guy says his car dyno's 1000hp, and it weights 3800lbs...but only goes 137mph in the 1/4..... Well then his dyno reading is WAY WAY wrong.

[@brianpardee1281]

always looked at people on dynos with cars and thought theyre fudging numbers knowing what my dads truck makes and some kids with less say they have more his truck is a 5.3ls

[@erikradzins]

Street N Jeep it happens. But there are plenty of people out there (like me) that always post up real numbers :)

[@josephhicks9158]

vid is too boring to get thru

[@erikradzins]

Sorry about that. I try to keep them short, I just talk a lot. lol