[Mjbmw1]

So i took a trip to Mosselman Turbos in Netherlands and got the car Dyno finally.
Crank 524 torque 814nm
I have 22,000 km when the dyno was run. Car is 8 months old. I drive between 180 to 240 daily. Always in sport mode and gas was 93 with old e10 so maybe half and half.

[130FeetDeep]

Originally Posted by Mjbmw1

So i took a trip to Mosselman Turbos in Netherlands and got the car Dyno finally.
Crank 524 torque 814nm
I have 22,000 km when the dyno was run. Car is 8 months old. I drive between 180 to 240 daily. Always in sport mode and gas was 93 with old e10 so maybe half and half.

Fully stock?

Odd, the dyno shows 525.1 hp. One interesting thing about that dyno is how much it shows is still on the table with this motor. BMW allows a big torque fall off and clearly there is a lot more peak hp on the table tuned.

[Mjbmw1]

Fully stock

[Thewolfbmw]

Great post on the M50i. You mentioned "Crank" but wouldn't these numbers be at the wheel?

[130FeetDeep]

Originally Posted by Thewolfbmw

Great post on the M50i. You mentioned "Crank" but wouldn't these numbers be at the wheel?

Notice the dyno say engine power. I assume he is on a MAHA or it is a guess a parasitic loss on drivetrain. MAHA do pretty well measuring that parasitic loss allowing the convert back to crank/engine.

[Thewolfbmw]

After a second glance, yes but it appeared to just be a title.

I am no expert and simply trying to gain more knowledge, so I apologize in advance for seeming newby'ish.

Obviously the dyno was on rollers, so they have to account for drivetrain loss. Do you know what percentage they used to account for the loss?

For example, if the dyno is assuming a 15% drivetrain loss, you would need to multiply 1.1765 by 445 crank hp to get 523 hp.

But again, I am just starting to learn the science of this. There are 100' of smart members here to help out.

Love that it looked like an all out party at the dyno place!! Cheers

[130FeetDeep]

Originally Posted by Thewolfbmw

After a second glance, yes but it appeared to just be a title.

I am no expert and simply trying to gain more knowledge, so I apologize in advance for seeming newby'ish.

Obviously the dyno was on rollers, so they have to account for drivetrain loss. Do you know what percentage they used to account for the loss?

For example, if the dyno is assuming a 15% drivetrain loss, you would need to multiply 1.1765 by 445 crank hp to get 523 hp.

But again, I am just starting to learn the science of this. There are 100' of smart members here to help out.

Love that it looked like an all out party at the dyno place!! Cheers

If it is a MAHA dyno, it actually measures parasitic loss, so you have an accurate figure. You are not using a fudge factor to get back to crank.

[Thewolfbmw]

Originally Posted by 130FeetDeep

If it is a MAHA dyno, it actually measures parasitic loss, so you have an accurate figure. You are not using a fudge factor to get back to crank.

Thank you

[speedyman]

I'm no expert either but have been around this stuff for 20 years and have never seen nor heard of a dyno that reads or somehow estimates what an engine produces at the flywheel, only at the wheel.
It is well known that BMW sig. underrates their HP/TQ #s. 525 would be in the realm of 600 flywheel which is more in line with the power needed to record a 0-60 time of 3.8 seconds by a 2.5 ton vehicle as reported by Car and Driver.
I've seen where many BMWs put there advertised HP/TQ #s to the wheel as is also commonly seen with Porsche. I'm really doubting that BMW decided to change course with the M50i and be balls on accurate.

[Mjbmw1]

Originally Posted by speedyman

I'm no expert either but have been around this stuff for 20 years and have never seen nor heard of a dyno that reads or somehow estimates what an engine produces at the flywheel, only at the wheel.
It is well known that BMW sig. underrates their HP/TQ #s. 525 would be in the realm of 600 flywheel which is more in line with the power needed to record a 0-60 time of 3.8 seconds by a 2.5 ton vehicle as reported by Car and Driver.
I've seen where many BMWs put there advertised HP/TQ #s to the wheel as is also commonly seen with Porsche. I'm really doubting that BMW decided to change course with the M50i and be balls on accurate.

There was also at wheel but I didn't print that one out. I have the video on Youtube you can see it there. You might be an expert but I was there and 20 other M cars lol.
There guys are running 580 to 620 crank M3 and M2 Comps with stage two turbos. We did several runs and they calibrated each time a car was put on the dyno.

[speedyman]

Originally Posted by Mjbmw1

There was also at wheel but I didn't print that one out. I have the video on Youtube you can see it there. You might be an expert but I was there and 20 other M cars lol.
There guys are running 580 to 620 crank M3 and M2 Comps with stage two turbos. We did several runs and they calibrated each time a car was put on the dyno.

I believe that you misread my post. I said "I'm NO expert". I do know however that BMW like Porsche seriously underrates their engine power on their website and in sales brochures.

[Ninefourteener]

Originally Posted by speedyman

I've seen where many BMWs put there advertised HP/TQ #s to the wheel as is also commonly seen with Porsche. I'm really doubting that BMW decided to change course with the M50i and be balls on accurate.

I thought the same thing, because both my previous two BMWs were both underrated. I "think" BMW does that, so they can't be sued later by someone that lives on the top of a 12,000 foot mountain, that mysteriously stays 105 degrees Fahrenheit all year long. I "think" their estimates are a "worst case scenario". Once you get down at seal level, in a cooler environment, hp numbers go up significantly.

With all that said though... I think the M50i is a bit more "spot on" than most previous BMWs. Mine dynoed (stock) at 536/826nm, or 529/609ftlb... depending on if you are in Europe or the US. But... essentially the same as the OPs numbers. Minor differences can be excused by elevation changes, temperature changes, or even lower quality gas.

The difference with the M50i.... is that it is MASSIVELY de-tuned from the factory. I gained 154 horsepower from a proper dynotune, on an otherwise stock vehicle. When the same company tuned a new X5M... they only got 10 more hp than me, and I suspect it's because an X5M can spin up a few hundred RPM more. I maxxed out at 6200 RPM, whereas the X5M maxxed out at almost 7000 RPM if I recall. Either way... only 10 more measly HP???

Keep in mind, the M50i is rated at 523, whereas the X5M is rated at 615 (I think?).... but unmodified and tuned.... they both produce the exact same numbers. The M50i just has a TON more "headroom".

[Tim2189]

Originally Posted by Ninefourteener

I thought the same thing, because both my previous two BMWs were both underrated. I "think" BMW does that, so they can't be sued later by someone that lives on the top of a 12,000 foot mountain, that mysteriously stays 105 degrees Fahrenheit all year long. I "think" their estimates are a "worst case scenario". Once you get down at seal level, in a cooler environment, hp numbers go up significantly.

With all that said though... I think the M50i is a bit more "spot on" than most previous BMWs. Mine dynoed (stock) at 536/826nm, or 529/609ftlb... depending on if you are in Europe or the US. But... essentially the same as the OPs numbers. Minor differences can be excused by elevation changes, temperature changes, or even lower quality gas.

The difference with the M50i.... is that it is MASSIVELY de-tuned from the factory. I gained 154 horsepower from a proper dynotune, on an otherwise stock vehicle. When the same company tuned a new X5M... they only got 10 more hp than me, and I suspect it's because an X5M can spin up a few hundred RPM more. I maxxed out at 6200 RPM, whereas the X5M maxxed out at almost 7000 RPM if I recall. Either way... only 10 more measly HP???

Keep in mind, the M50i is rated at 523, whereas the X5M is rated at 615 (I think?).... but unmodified and tuned.... they both produce the exact same numbers. The M50i just has a TON more "headroom".

Not to mention that both cars have the same Torque numbers

[GOLFFRR]

great data. Thanks for posting

[speedyman]

Originally Posted by Tim2189

Not to mention that both cars have the same Torque numbers

The TQ #s being the same is huge as that is really what makes this type of heavy vehicle "fun to drive". These aren't little sports cars where you work at it winding them up like a chainsaw to ge the power.
There is no doubt in my mind the the M50i is at least 600 at the flywheel. Use any of the online calculators to figure a close estimate of the true crankshaft HP output based on vehicle weight weight and 0-60/1/4 mile times

[speedyman]

You need 630 crankshaft/flywheel HP plugged into this calculator with a weight of 5,200 lbs to yield a 12.37 second 1/4 mile @ 115 MPH.

https://robrobinette.com/et.htm