Another stock F80 M3 6MT dyno

[Jaded M3]

Great results!

[Black Gold]

Originally Posted by Boss330

I'm no expert on Vettes, but here's what I found after a quick search:

http://forums.corvetteforum.com/c7-t...rb-weight.html



So, 3411lbs as weighed by owner.

Here is a F82 DCT weighing in at 3564lbs:

http://f80.bimmerpost.com/forums/sho....php?t=1023335

A difference of 153lbs/69kg.

The m4 has half tank of gas, so add 60 lbs to that at least

[A418t81]

Originally Posted by bruce.augenstein@comcast.

What was the dyno correction factor for this run?

Just a side note: The car actually does nose over at higher rpm from a driver's perspective. Note the falling torque curve.

No offense. This is arguably a terrific engine.

From a driver's perspective, it does not nose over all at (as the dyno shows). The torque curve falls off in a linear fashion to keep that peak power plateau that you see. If the power dropped off, you would feel it nose over. It doesn't do that in the slightest as is clearly demonstrated here.

[turbo8765]

What were the uncorrected numbers?

BMW haven't suddenly forgotten how to measure and state hp. THE M4 IS NOT UNDERRATED.

It has LOWER DRIVE TRAIN LOSSES than the e92. Why do people have such a hard time understanding such a simple concept.

[turbo8765]

Allow me to elaborate.

Reasons why the M4 dyno numbers are higher than expected

1. A correction factor is being applied to a turbo motor that has already corrected itself (as your uncorrected numbers will confirm)
2. Lower drive train losses due to factors such as electric steering and a carbon fiber drive shaft

The M4 absolutely makes 430 crank hp. Drive train losses are likely 11-12%.

Reasons the wheel horsepower delta between the s65 powered e92 and the s55 powered M4 are greater than expected

1. The e92 has greater drive train losses due to factors such as hydraulic power steering. (How much power do you think it takes turn a hydraulic pump at 8400 rpm?)
2. The s65 is a high compression NA motor running a very aggressive timing curve. It's able to do so because the intake system is so well designed that IATs=ambient above 20 mph. This OBVIOUSLY is not the case on the dyno, therefore the DME pulls timing reducing power.

It really is that simple.

[CanAutM3]

Originally Posted by turbo8765

2. Lower drive train losses due to factors such as electric steering and a carbon fiber drive shaft.

In general, I don't disagree with your post.

Note however that ancillaries (such as a power steering pump) or inertial effects (reduced by the carbon fibre driveshaft) are not part of drivetrain losses per se.

[bruce.augenstein@comcast.]

Originally Posted by A418t81

From a driver's perspective, it does not nose over all at (as the dyno shows). The torque curve falls off in a linear fashion to keep that peak power plateau that you see. If the power dropped off, you would feel it nose over. It doesn't do that in the slightest as is clearly demonstrated here.

From your perspective, it doesn't nose over, and that's because the increased sturm and drang from the rising revs fools you. There have been plenty of posts in regard to the E9X claiming that car would pull harder as it rose toward the red line, but such was and is not the case. In point of fact, any given car, in any given gear, will accelerate according to its torque curve, and horsepower doesn't particularly matter in that regard.

Just to address power directly, however, there is the fact that "speed eats power", meaning that if you can accelerate at a given rate at, say, 25 MPH, you will need exactly four times that amount of power to accelerate at that same rate at 100 MPH, ignoring changes in wind and rolling resistance. In turn, this means that for each MPH gained, the next MPH will take more time to attain than the last one, given the same power. Therefore, the acceleration rate is reduced as speeds climb with constant power.

What max power buys you is that, at any given vehicle speed, you are accelerating at the very best rate the car is capable of - even though you are accelerating at a lesser rate in that gear than you were at max torque (at a lower speed, of course).

With the torque curve dropping acceleration is reduced, period - although I admit that "nose over", may be slightly too harsh a term. Proportionally reducing acceleration as speeds climb with constant power just means less acceleration with each MPH gained, so a proportional change in acceleration from, say, 60 to 61 MPH won't feel like much.

Capiche?

[A418t81]

Originally Posted by bruce.augenstein@comcast.

From your perspective, it doesn't nose over, and that's because the increased sturm and drang from the rising revs fools you. There have been plenty of posts in regard to the E9X claiming that car would pull harder as it rose toward the red line, but such was and is not the case. In point of fact, any given car, in any given gear, will accelerate according to its torque curve, and horsepower doesn't particularly matter in that regard.

Just to address power directly, however, there is the fact that "speed eats power", meaning that if you can accelerate at a given rate at, say, 25 MPH, you will need exactly four times that amount of power to accelerate at that same rate at 100 MPH, ignoring changes in wind and rolling resistance. In turn, this means that for each MPH gained, the next MPH will take more time to attain than the last one, given the same power. Therefore, the acceleration rate is reduced as speeds climb with constant power.

What max power buys you is that, at any given vehicle speed, you are accelerating at the very best rate the car is capable of - even though you are accelerating at a lesser rate in that gear than you were at max torque (at a lower speed, of course).

With the torque curve dropping acceleration is reduced, period - although I admit that "nose over", may be slightly too harsh a term. Proportionally reducing acceleration as speeds climb with constant power just means less acceleration with each MPH gained, so a proportional change in acceleration from, say, 60 to 61 MPH won't feel like much.

Capiche?

There's so much here that is out in left field I don't don't even have the time, or energy to argue with you over it. Lets agree to disagree. Ugh.

[CanAutM3]

Originally Posted by A418t81

There's so much here that is out in left field I don't don't even have the time, or energy to argue with you over it. Lets agree to disagree. Ugh.

Maybe you should argue your point, because Bruce is pretty much bang on here IMO.

[A418t81]

Nope. I'll leave you guys to your calculators, simulators, pocket protectors, and 2 hour long post preparations. Not worth it to me. It's just the internet

[Boss330]

Originally Posted by A418t81

There's so much here that is out in left field I don't don't even have the time, or energy to argue with you over it. Lets agree to disagree. Ugh.

Originally Posted by A418t81

Nope. I'll leave you guys to your calculators, simulators, pocket protectors, and 2 hour long post preparations. Not worth it to me. It's just the internet

This is a typical acceleration graph taken from a real world test using g-force sensor equipment. As you can see, the g-forces continue to fall as speed increases. This is not "just the internet", this is how the laws of physics work...

[bruce.augenstein@comcast.]

Originally Posted by A418t81

Nope. I'll leave you guys to your calculators, simulators, pocket protectors, and 2 hour long post preparations. Not worth it to me. It's just the internet

Ok, I get it. It's just the Interweb, and you don't directly know anyone, so it's OK by you to look like an ignoramus with an attitude.

But what if someone you actually know (and has reasonable automotive knowledge) reads this string?

Sheesh. Then if you don't already have a reputation as an ignoramus with attitude amongst folks you know, you'll be outed!

[CanAutM3]

Originally Posted by Brosef

I'm equally impressed with the sound of the exhaust in this pull. you can definitely hear the valve open at 23 seconds

nice numbers

Just my impression: I think the sound we hear at 0:23 is the engine going full throttle. IMO, the valves open at 0:27.

[ES BMW]

Originally Posted by bruce.augenstein@comcast.

Ok, I get it. It's just the Interweb, and you don't directly know anyone, so it's OK by you to look like an ignoramus with an attitude.

But what if someone you actually know (and has reasonable automotive knowledge) reads this string?

Sheesh. Then if you don't already have a reputation as an ignoramus with attitude amongst folks you know, you'll be outed!

Some of us like to read informative posts with numbers that like, make sense.

[dmk08]

I knew I had this laying around somewhere. Same dyno as OP.

2008 E90 6spd. Turner Test pipes. BPM stg II. Drop in filter. (my old car)



I can't find the sheet for my 11 for some reason. But I want to say it made 368 on this dyno. Challenge X, Dinan Rear, Evolve STG II, DCT.

Edit:

Here is my buddy Evans E90 on the same dyno. Custom full exhaust, custom tune (Technica in ATL), and intake.



Funny comment after reading these two sheets. My car always pulled his. Both 6MT. Every run.

[MisterEm]

Originally Posted by dmk08

I knew I had this laying around somewhere. Same dyno as OP.

2008 E90 6spd. Turner Test pipes. BPM stg II. Drop in filter. (my old car)



I can't find the sheet for my 11 for some reason. But I want to say it made 368 on this dyno. Challenge X, Dinan Rear, Evolve STG II, DCT.

Edit:

Here is my buddy Evans E90 on the same dyno. Custom full exhaust, custom tune (Technica in ATL), and intake.



Funny comment after reading these two sheets. My car always pulled his. Both 6MT. Every run.

Great data for this argument sake.

Much appreciated.

[shortseller]

Originally Posted by My E90

Some of us like to read informative posts with numbers that like, make sense.

As do some of us that have no clue...after it goes beyond the basics.

My take on all this, it's very fast.

[JeffM-Houston]

It's a true engineering masterpiece not just another FI tuned run of the mill engine. The S65 is a real exotic racing engine IMO

The S55 in the F8x is a closed deck block with forged crank, among other things. Not exactly a run of the mill motor in a street car.

[dmk08]

Originally Posted by shortseller

As do some of us that have no clue...after it goes beyond the basics.

My take on all this, it's very fast.

It may not be faster than all E9x. But judging on my power #s above and the #s Bruce posted it's sure gonna be faster than mine lol.

[RingMeister01]

Dude the break-in procedure. You're my f**cking hero

[RingMeister01]

Originally Posted by A418t81

Nope. I'll leave you guys to your calculators, simulators, pocket protectors, and 2 hour long post preparations. Not worth it to me. It's just the internet