To The People Losing Their Minds About My E36 M3's Dyno Results, Here's An Explanation
This video has caused a lot of confusion in the YouTube comments, with people saying stuff like “I thought he was a car guy… This dyno doesn’t measure bhp. It measures whp. 279 x15% loss is around 317” and “You guys are aware that dynos read WHP and not BHP?“
So to set the record straight, I Facebook messaged Charlie from Surrey Rolling Road this morning and asked for an ‘official’ response on the matter. Here’s what he sent back, which I’m hoping will clear things up for people…
What does the dyno measure?
WHP
Are the figures for Alex’s car at the crank or wheel?
Crank
Whoa… you just said that the dyno measures at the wheels!
It’s common in Europe for dynos to add the drivetrain loss to make a crank estimation graph. It is always an estimate but it allows the customer to relate to the manufacturer’s crank figures.
Does the dyno also plot in WHP?
Yes, it stores a WHP graph for every car, then depending on what the customer wants we can print out WHP or crank HP.
Why do I see lots of WHP figures around the internet?
America uses mainly WHP figures only, as does Russia and the middle East. Australia uses Wheel KW mainly.
So who’s right?
No one, and everyone. There is no wrong or right way of doing it. As long as you get a consistent number you can compare to when you’ve done some mods.
What do you think is wrong with Alex’s car?
Alex bought it. It was probably putting out over 300bhp before he got his hands on it…
So there you have it, ladies and gents. From the horse’s mouth, this is why my car was making 279bhp at the crank and not 279bhp at the wheels (that would have been incredible had that been the case!).
Next up, I’ll give the car a proper service, get those valve clearances and suspension issues straightened out, and will fit a new exhaust system and a Pipercross air filter that was donated to Colin just last week.
Then, it’ll be back to Charlie’s dyno to see if my E36 M3 can get over 300bhp (at the crank).
Comments
https://youtu.be/BqzUlbgYOEc
fifth gear made a great episode of this
Next time use a real rolling road, Track ‘n’ Road in essex is spot on. It’s used to race prep cars and certify for power restricted classes
Last time i looked my Rolling road was certainly real, I mean after 15000 cars and 12 years it certainly seems to work like a real rolling road. Would you like to clarify exactly whats not ‘real’ about my rolling road?
I hardly doubt that your vanos is working properly. Typical is that if you have top power, but no lowend torque, or have low end torque, but less power at the top like you actually have. Refresh that vanos and you’ll be at your original 321hp.
That car had a complete vanos refresh not long ago…
VANOS KICKED IN YO!
Of course people use whp. I’ve seen hundreds of dyno sheets from Europe where they convert power from wheels back to crank and it’s hilarious as you would find dyno sheets saying that 100hp at the wheels is 168hp crank and that’s for fwd car. It’s absolut bullshit… One guy built R33 in UK what was supposed to have over 1000hp at crank but according to dyno sheet power lost between crank and wheels was so big that the car would not have enough power to move with standard engine in :D
My E21 just got it’s valve clearances adjusted and it made the engine feel sooooo awesome… looking foward to your next vídeo Alex
Heres an Explanation/excuse to make it look like Collins is not slow
Even your website adds are hinting at something
LS engines are way to expensive here in Europe for what they are
I honestly didn’t care, just give us more Colin content xD
Comparing chassis dyno numbers…bhp or whp…is uselss anyway. The dyno is a tool, not a field for bragging rights. All dynos measure differently, and ambient conditions will play a big factor as well. Plus, as far as calculating bhp, not all cars have 15% loss through the drivetrain. It may be a little bit less than that considering its a manual. 15% is often a general number for automatics…again this often can vary between cars. A lot of manual cars can have 10-12% loss.
“BHP at the wheels”?
Quote from wikipedia:
“It is the measure of an engine’s horsepower before the loss in power caused by the gearbox and drive train.” If you talk about BHP, you are always talking about HP at the crank.
Which is certainly more than WHP (Wheel HorsePower) gearbox and drive train always make a loss on power.
BHP at the wheels is not a thing.
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