Is S65 power output overrated?

[Petros]

Has anyone actually put an S65 on an engine dyno to verify power output? I'm beginning to grow skeptical of the claimed 414 hp stock given the new F80 M3 dyno curves. That car is officially rated at 425 hp yet consistently puts well over 400 whp. The E90 M3 is rated at 414 hp and dynos at 330-350 whp. There's no reason to believe drivetrain losses between the two platforms are any different. And it's a given that BMW tends to underrate the power of their turbo engines. But the difference in whp between the two platforms is just too drastic! Either the F80 is actually putting out at least 470-480 hp at the crank (which would make the stated 425hp understatement of the millenium), or the S65 might not be putting out the claimed 414 hp.

[BrewRifle]

The S55's are underrated. S65's might be a tad overrated.

[Shredicus]

Bmw is notorious for underrating their turbo motors

[dmk08]

I think the S65 is decently overrated and the S55 is slightly underrated.

[Law]

I think enough time has gone by where if the S65 were underrated we would've known by now.

[Ezio]

Take a 2011 mustang GT with 412BHP stock weighing around 3600-3700 pounds

Then look at a E92 M3 with 414BHP stock weighing about the same.

put them in a straight line and they are pretty even. pointing being i feel the M3 is at least a 400BHP car. looking at how fast the car is.

[Petros]

Originally Posted by Ezio

Take a 2011 mustang GT with 412BHP stock weighing around 3600-3700 pounds

Then look at a E92 M3 with 414BHP stock weighing about the same.

put them in a straight line and they are pretty even. pointing being i feel the M3 is at least a 400BHP car. looking at how fast the car is.

How much does the mustang dyno? Is it the same as the M3?

[FormulaMMM]

Originally Posted by Ezio

Take a 2011 mustang GT with 412BHP stock weighing around 3600-3700 pounds

Then look at a E92 M3 with 414BHP stock weighing about the same.

put them in a straight line and they are pretty even. pointing being i feel the M3 is at least a 400BHP car. looking at how fast the car is.

Yes. Another example

I'd say it's rated right on.

[Ezio]

Originally Posted by Petros

How much does the mustang dyno? Is it the same as the M3?

they put down 350-360WHP stock. if you look around on the mustang forums. Which is why i think the M3 might be more of a 400BHP car, instead of 414HP.

[FormulaMMM]

More

[Sered]

Originally Posted by Petros

Has anyone actually put an S65 on an engine dyno to verify power output? I'm beginning to grow skeptical of the claimed 414 hp stock given the new F80 M3 dyno curves. That car is officially rated at 425 hp yet consistently puts well over 400 whp. The E90 M3 is rated at 414 hp and dynos at 330-350 whp. There's no reason to believe drivetrain losses between the two platforms are any different. And it's a given that BMW tends to underrate the power of their turbo engines. But the difference in whp between the two platforms is just too drastic! Either the F80 is actually putting out at least 470-480 hp at the crank (which would make the stated 425hp understatement of the millenium), or the S65 might not be putting out the claimed 414 hp.

The S65 is very sensitive to IATs. And the N54 was underrated too, but not by as much. Stock the N54 makes about 330hp when rated at 300.

[Petros]

Originally Posted by Ezio

they put down 350-360WHP stock. if you look around on the mustang forums. Which is why i think the M3 might be more of a 400BHP car, instead of 414HP.

Sounds reasonable. 400 hp would be more in line with what our cars are getting on the dyno

[Sered]

Originally Posted by Petros

How much does the mustang dyno? Is it the same as the M3?

About 370whp generally. The M3 has a very peaky powerband and so the 6MTs lose a lot of mph due to both the slower shifting and the one less gear which keeps them out of the powerband briefly on the 1-2 and 2-3 shift. The 5.0 doesn't have this problem (partly due to extra displacement but mainly because the people who designed the transmission and final drive ratio setup weren't morons)

[blankstar43]

Originally Posted by Petros

Has anyone actually put an S65 on an engine dyno to verify power output? I'm beginning to grow skeptical of the claimed 414 hp stock given the new F80 M3 dyno curves. That car is officially rated at 425 hp yet consistently puts well over 400 whp. The E90 M3 is rated at 414 hp and dynos at 330-350 whp. There's no reason to believe drivetrain losses between the two platforms are any different. And it's a given that BMW tends to underrate the power of their turbo engines. But the difference in whp between the two platforms is just too drastic! Either the F80 is actually putting out at least 470-480 hp at the crank (which would make the stated 425hp understatement of the millenium), or the S65 might not be putting out the claimed 414 hp.

Actually wouldn't the drivetrain loss be different since the new m3 uses carbon fiber pieces in things like the drive shaft?

[FR01]

Originally Posted by Petros

Has anyone actually put an S65 on an engine dyno to verify power output? I'm beginning to grow skeptical of the claimed 414 hp stock given the new F80 M3 dyno curves. That car is officially rated at 425 hp yet consistently puts well over 400 whp. The E90 M3 is rated at 414 hp and dynos at 330-350 whp. There's no reason to believe drivetrain losses between the two platforms are any different. And it's a given that BMW tends to underrate the power of their turbo engines. But the difference in whp between the two platforms is just too drastic! Either the F80 is actually putting out at least 470-480 hp at the crank (which would make the stated 425hp understatement of the millenium), or the S65 might not be putting out the claimed 414 hp.

Mine dynoed 353hp on a dynojet. They calculated 23-25hp in drivetrain loss (a slow down test in neutral). It was about 73deg, car had akra evo but not tuned yet.

Dude said it bones always have missing HP, granted I need to retest now that I have my tune.

I feel the F8X M3/4 rating is higher to compensate for heat soak loss. Almost as if they try to keep the minimum HP at the stared value...

[isherdholi]

Originally Posted by Petros

Has anyone actually put an S65 on an engine dyno to verify power output? I'm beginning to grow skeptical of the claimed 414 hp stock given the new F80 M3 dyno curves. That car is officially rated at 425 hp yet consistently puts well over 400 whp. The E90 M3 is rated at 414 hp and dynos at 330-350 whp. There's no reason to believe drivetrain losses between the two platforms are any different. And it's a given that BMW tends to underrate the power of their turbo engines. But the difference in whp between the two platforms is just too drastic! Either the F80 is actually putting out at least 470-480 hp at the crank (which would make the stated 425hp understatement of the millenium), or the S65 might not be putting out the claimed 414 hp.

Actually there is.

The F8x has a carbon fibre propshaft. Much lighter than the E92's and should definitely help reduce drivetrain loss.

[GoKimiGo!]

Comparing two different cars based on dynometer figures posted online is a bad idea. The F8x makes more power than the E9x, everyone knows that. The difference between the two would be better gauged on a drag strip with the same driver rather than on paper.

A lot of people have said it before but I'll say it again. Dynos aren't great tools for measuring horsepower or torque. They are good for getting a general idea of percentage based gains made from modifications and tuning. Also drivetrain loss comparison between two platforms will vary, there is no such a thing as a fixed loss percentage. As mentioned the one piece carbon drive shaft might just be doing what it was designed to.

[Helmsman]

Probably true that a dyno is better measure changes on the same engine but with F8x measuring significantly above spec while E9x is well below I'd say it is fair to claim BMW is playing some marketing tricks here.
I certainly wouldn't complain getting more power than specified, but looking at what seems to be 15% drop in the E9x surely must be viewed as overrated... Doesn't change the way the E9x run - which is great - but again the huge gap in the way BMW specify I personally think is on the borderline for being professional.

[modkrazy]

No, no one has ever put the S65 on a dyno, ever.

[tbone28]

The sound is not overrated

[roastbeef]

Originally Posted by blankstar43

Actually wouldn't the drivetrain loss be different since the new m3 uses carbon fiber pieces in things like the drive shaft?

There was a great response in a thread, but I can't locate it on my phone. Search "carbon fiber driveshaft" and you should be able to find it. It's a good read with interesting responses.

[LarThaL]

Originally Posted by Petros

Has anyone actually put an S65 on an engine dyno to verify power output? I'm beginning to grow skeptical of the claimed 414 hp stock given the new F80 M3 dyno curves. That car is officially rated at 425 hp yet consistently puts well over 400 whp. The E90 M3 is rated at 414 hp and dynos at 330-350 whp. There's no reason to believe drivetrain losses between the two platforms are any different. And it's a given that BMW tends to underrate the power of their turbo engines. But the difference in whp between the two platforms is just too drastic! Either the F80 is actually putting out at least 470-480 hp at the crank (which would make the stated 425hp understatement of the millenium), or the S65 might not be putting out the claimed 414 hp.

The S65 needs ideal conditions to make its stated power as it is a highly tuned NA motor. The F8x motor is way underated. This seems to be a common phenomenon with all the German car makes. My S6 is rated at 420 stock, but makes 470-480 repeatedly in independent tests.