Hi folks,

Scoobybslayer made an interesting topic recently highlighting the difference in figures he had found due purely to the dyno operators placement of the air inlet probe and there was a lot of interest in it as not many people know how easy it is to manipulate dyno figures.

During the discussion it was decided since I was in a great position to do so - I would do some tests and log the data for all to digest and learn from when I had a suitable vehicle to use for a while, so, if you want to see how to find over 70bhp at the wheels without even bothering to tune the car.... Watch the video.


Now learn, discuss and enjoy.

 

Nothing to discuss stu, you've answered all the questions you asked in the vid

But just to clarify, the temp sensor can be moved all over the shop but the temp sensor for the dunk cell remains in one fixed location?

 

It is plain to see that fake, The question is how can it be hidden and how can you spot it.

Mark

 

thanks for making this vid. iv learnt so much that i never knew.

 

Makes sense how all the lower spec cars make big figures. Thanks for the info

 

forgive my ignorance, if you were to put the probe in iced water would the opposite be true? I know you're unlikely to want to down play bhp, but just out of interest.

 

who cares about figures, i grew out of it when i was about 20yrs old

aslong as its set up to its best and goes like stink i couldnt care about bhp figures.

its so hard to find an honest tuner like the ones on this thread, well done stu for sharing this with us.

ive been to a tuner and been told i had 200bhp from a rst with just a chip and actuator lol

 

Who's that sexy dude next to the fan?

 

Yes it would go down

 

Nice to know these things ,for the moment and for all my tunning so far I use le butt dyno ,an Im guessing most of are impressions of power and speed come from this ?

 

at least you've quoted atw figures and not "corrected" flywheel figures

 

Example.
When tuning normally aspirated vehicles it's very hard work and requires careful tweaking of fuelling, spark and cam timing just to get say 10bhp. Now given a dyno tune is around Ł150 from most places, how do you know your Ł150 was well spent? Because the graph shows an extra 10bhp so your happy? Or a NASP remap for say Ł200 or more. How do you quantify that you received what you paid for?

How many people would even have thought to check the air temps from both before and after runs only an hour apart are roughly the same, or to question it if not? That's the purpose of this topic. Why is one 500bhp cossie so much faster than another when they both show almost identical power curves on their dyno graphs? The answer is often within this topic.

There are not many tuners would touch a topic like this with a barge pole but those of us who want to give you what you paid for no matter what are happy to show our customers just how to check the figures we give you are true. This video has proven I could have given this customer a graph showing he had 560bhp. Many would have done just that... And I could even name some.. Lol

 

I have had the displeasure of watching someone move the probe whilst mapping a car

Steve

 

where would a manufacturer have the probe when testing and then stating the power a particular model of car makes? surely there needs to be some sort of standard to be followed across the board to allow an accurate comparison?

 

one more q - prob for stu - how close to the edge are cars actually mapped(appreciate this'll vary from one to the next)? whilst moving the probe around gives a nice () increase in power would it possibly lead to the engine going lean and melting, or does what temp the dyno see's and calculates from have no bearing on spark & fuelling?

 

Thank you for taking the time to post such a useful video, you briefly point out that for mapping you use inlet temps from the wall, and for power runs you use just in front of the inlet, is there a reason or is it just to try and give higher BHP figures on the graph?

Also is the probe not a calibrated item? Which if the dyno operator wanted they could simply +10 degrees onto its calibration file and there you go - an instant 5% extra horsepower?

 

it has no relevance on the tune of the car whatsoever, it is purely a correction factor the dyno software uses to convert the power reading to an industry standard.

 

cool, so 'just' fraud rather than dangerous

 

excellent work, glad you got to do this stu really shows how easy it is to manipulate.
is that with dd own correction factor ? can those runs be viewed in din and sae corrections aswell ?

 

Interesting topic.

 

Ok, this ones complex but I will try to keep it as simple as I can.
The correction factor brings all the figures back to a known standard so that a car can be tested anywhere in the world, at any atmospheric pressure, humidity or temperature level and still return a known figure. If this wasn't done we would end up with problems like "yeah, the BMW may be 300bhp but that's German bhp, if it was 300bhp in Switzerland it would be much faster as its a lower atmospheric pressure in Sweden"

So, the air temp part of the calculation is trying to get the air temp back to whatever the standard was determined to be.. I think the DD one is 25c. The algorithm suggesting that for every x degree over 25c your engine should have lost x power so it corrects it back. This means you will have power fluctuations with inlet temp, which is of course absolutely correct and the dyno should try to compensate for it. However, when I am mapping and looking for say, a 1% power gain from some spark (5bhp on a 500bhp engine) I dont really want the dyno messing about with correction figures, I want absolute 100% consistency run after run and I couldn't care less how accurate the actual figure is as long as the gain itself is real. In my cell that's feasible as the cell temperature control is awesome and even at 500bhp I can do ten runs back to back and not raise the cell temp even 1 degree c, so whatever I am measuring is going to be far more accurate if I ensure the air probe correction is doing sod all on each run.

For power runs, I think the inlet temp is an integral part of the equation if you want a real world figure so long, as the video proves, it truly is indicative of the air temp the engine is ingesting into its air filter. Certainly far more so for nasp than turbo which can never actually be truly accurate, but that's another topic altogether.

Does that even make sense? It's been a long day and I'm in bed. Lol

 

Can't wait for the drive home top job stu as always

 

When I bring my car to you I want mine ran on the dyno with the probe on the turbo lol 450bhp on a t34 yeah boy!!!

 

Im pleased you found the time and interest to do this thread after scoobyslayer's suggestion.

Steve

 

Top info Stu.You explain it easy for us thick boys lol.

 

so realy it just goes to show a dyno can give you bullshit figures

No disrespect Stu , but tell us something we didnt know

Tuners have been bullshitting fools with to much money for years

And as you keep going with your Dyno , im sure you will find many many other ways of bullshitting the figures

The question is after a while and when you have a quiet spell will you realy care , lol, as there isnt a trade in the world that doesnt have ways of bullshitting the figures to make a few extra quid .

Tuners are just lucky , there the only trade where the customer is happy the higher the figures go ,, lol

 

I'd like to see an answer to this. What are other ways of cheating that might be harder to spot?


Although a lot of people probably wouldn't have a clue they're being cheated even if they saw the probe over the turbo.

 

very good

some dynos will give non corrected and a corrected bhp so you can see

 

[QUOTE=North Yorks RS Spares;6287198]so realy it just goes to show a dyno can give you bullshit figures

No disrespect Stu , but tell us something we didnt know

Tuners have been bullshitting fools with to much money for years

And as you keep going with your Dyno , im sure you will find many many other ways of bullshitting the figures



there is no bullshitting times tho

 

Who's hacked Paul's account!!!
Lol

 

That was indeed the sole point of the video. To educate people who don't know any better.


"You" may know exactly how to do it and spot a real graph from a fake one, and of course after operating dynos on and off for over 16 years I also know, but there are thousands on here who don't know and its those people this discussion is aimed at. If your bored and cant learn anything, move on to another topic - there are plenty around to choose from.


I cant see me learning anything new that I havent already known for 16 years Paul, but you never know, and If I do, I will try and educate people about it so they don't fall foul of it. Just like I did in my large Fast Fords article all about Dynos years before I bought this one.


Speak for yourself mate. We don't bullshit our customers, and consider this.... if we did, would I really put a video on my YouTube channel teaching people how to catch me out?

 

The dyno only reads effort at the tyres (Not wheels btw, its actually quite different as a different set of tyres or pressures will affect the reading too)

The correction factors only affect how much BHP and Torque that is converted to. The AFR is simply a wideband and is unaffected by the corrections.

There are a great many ways a bad dyno can lead to bad and/or very unsafe mapping, but Im not sure if that's what your asking so will refrain from waffling on at the moment in case I am off on a tangent. LOL

 

Thats EXACTLY why I decided this video was a good idea mate. There are far too many Dyno's out there giving the good ones a bad name so a bit of education isnt a bad thing in my opinion.

 

Speak for yourself mate. We don't bullshit our customers, and consider this.... if we did, would I really put a video on my YouTube channel teaching people how to catch me out? [/quote]

But some would say that this was exactly why you did it , to give people a faulse sence of security that you will be the only honest person ever to own a Dyno



And for the record , I am not questioning your integraty at all , but i bet some will

And no i wouldnt have any idea how to tell a real Dyno sheet from a fake one , and i dont realy care as there all bloody fake , lol and thats a fact that im sure everyone with any brains will already know as we have seen these 450bhp cossies on a t34 and greens ,,lol

And i dont have a Dyno stu so cant speak for myself as my prices are my prices and i dont prommise big BHP gains from selling used parts so no need to frig the figures , lol

My comment regards ," tell us something we didnt know " was a bit tounge in cheek as im sure we are all aware that dyno figures have been doctored in the past .

Good of you to post your findings and maybee education is a good thing , but who will ever believe Dyno figures ?

Maybee your updates with the answers will help people understand that figures are being frigged , will this put faith in dyno"s or just make people not bother with them ?

My replies may look as tho im having a pop at you but im not , i just think that trying to educate folk on the bad points of others who have Dynos will probs make you look bad in there eyes and make you look as tho you are trying to say that you will be the only honest Dyno in the country , and im sure you wont be the only Honest one , but at least users may feel you will be one of the Honest ones and that cant be a bad thing for yourself and your customers

So if my replies look bad against you Stu , i dint mean them to be , i was just saying that history shows that Dynos tell lies ( or the operators do ) , lol

 

ffs lol if all dynos are fake we may aswell all say we have warp factor 1 - 9 and just judge it by the seat of the pants, maybe that would be more accurate !

a dyno coupled with real world performance is the ONLY way to judge power I cant see how any true petrol head could view it any other way tbh.

I love highly tuned stupidly quick cars and I like to know where and how much power they make and its nice to be able to see how certain corrections affect the figures.

ps stu, would you be able to view that cuppa tea run next week in sae correction mode and link it ? that should make it show even more power ?

 

Its not the Dynos that are fake , its the figures that the user gives that are fake , isnt that what Stu is trying to prove ?

So i quess half the fiqures given may as well be ," warp factor nine " , as thats about as realistic as they are

 

Paul, I think that you have a point regarding bullshit figures, there are lots around, Stu is just demonstrating how easy it is to make a 380ish Bhp genuine car appear to have 450+Bhp just by frigging the inlet temp sensor! A lot of graphs won't even print out the air temp/air pressure.

However, the MSD set up looks fantastic as far as I can see, the entire point of the cell build has been to provide reliable, and more importantly repeatable conditions to perform dyno testing as a means of measuring improvements... That's the important thing, the headline figure is always a "best guess" due to the huge number of variables thrown in (as Stu says, even tyre pressures etc can change the readings!), but the majority of sensible people will know roughly what a specific tune level will give them, if you really think a T34 on greens will make 450 then it's the owner who is deluded not the dyno! IMHO I always take the headline figures with a 10% bullshit factor, it's the shape of the curve & a safe AFR across it that are the important things.

 

Great thread
Surely an Engine bench Dyno is the best way to prove Power or at least get a tad nearer to the truth. Then on a RR to check if your operator is squeaky clean like Stu or a Barsteward like the rest .

 

I like discussions on this type of thing, it helps realise that there are so many factors involved, but also sometimes it's best not to over analyse it either.
No one should lose any sleep over it +/-10% does not matter to me personally but it's a good laugh to see some people get all anal about it.

 

You can easily con the readings on a bench too Rod ! Speak to Julian he says the mount of 600 bhp yb's hes seen with a graph and then tested them himself is unreal , Many haven't touched 500 let alone 600