Another stock F80 M3 6MT dyno

[A418t81]

1300 miles. Broken in on the Nurburgring, SPA, and the Autobahn.

Bone stock, 93 octane. 86 deg, 55% humidity. This was a hot dyno run. I made a pull about 30 seconds earlier, but something weirded the car out and power numbers were low. Slowed the drum down and immediately made another pull.

All I have to say is you people can run your silly computer simulations all day long. The car is making a lot more than 430 crank hp. The S65 powered cars on this dyno make 355-365 whp. He has dyno'd over 5000 cars on this dyno.

Power feels great. Pulls hard all the way to 7500 rpm by the butt dyno which is confirmed here. Again, those saying it noses over around 6500 need to recalibrate their butt dynos. 400+ whp for around 2k rpm power plateau. Awesome

[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

[Black Gold]

Nice work and I love your car

6mt white m3 ftw

[dmk08]

Dynolab is a legit dyno here in ATL. Many people use them.

My FBO E92 put around 380 on that dyno.

(And FWIW my friends FBO E90 put down around the same.)

[solstice]

425 whp. What 425 crank hp car does that? None.
Another dyno showing 70 whp up on the S65. How many more do we need?

[dmk08]

Originally Posted by solstice

425 whp. What 425 crank hp car does that? None.
Another dyno showing 70 whp up on the S65. How many more do we need?

Who cares what it's up on the S65? Are new M owners egos really that fragile?

[solstice]

Originally Posted by dmk08

Who cares what it's up on the S65? Are new M owners egos really that fragile?

What?

I've said many times that I think the S65 beats the S55 in every aspect except power. I'd rather have an S65 in my F80. 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. However the notion that the S55 is generating no more than rated power is just beyond me given the overwhelming indications of under rating.

[dmk08]

Originally Posted by solstice

What?

I've said many times that I think the S65 beats the S55 in every aspect except power. I'd rather have an S65 in my F80. 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. However the notion that the S55 is generating no more than rated power is just beyond me given the overwhelming indications of under rating.

Sorry didn't know people were still saying this. If anything I think the S65 is a little over-rated in actual power numbers. No big deal tho cause it still performs and is fun to drive.

[solstice]

Originally Posted by dmk08

Sorry didn't know people were still saying this. If anything I think the S65 is a little over-rated in actual power numbers. No big deal tho cause it still performs and is fun to drive.

Agree 110%. The S65 is the best thing south of a Maranello engine and maybe a Metzger Boxer. It's fantastic and will be known as one of the best engines ever.

[JoeFromPA]

And this is why the F80/F82 has such traction issues. You are routing this power through 275 wide rear tires setup for some degree of longevity.

First car I'm ever going out of my way to take to a drag strip. I want to see what mine traps

[dmk08]

Originally Posted by JoeFromPA

And this is why the F80/F82 has such traction issues. You are routing this power through 275 wide rear tires setup for some degree of longevity.

First car I'm ever going out of my way to take to a drag strip. I want to see what mine traps

Sometimes wheel spin can cause higher trap times if I remember correctly. I was a drag racing fan in my younger life lol. Thats why I wonder if we see closer to 117 in some tests and 120 in others.

[Boss330]

Originally Posted by solstice

425 whp. What 425 crank hp car does that? None.
Another dyno showing 70 whp up on the S65. How many more do we need?

Originally Posted by solstice

What?

However the notion that the S55 is generating no more than rated power is just beyond me given the overwhelming indications of under rating.

Then why don't we see higher trap speeds than for instance the C7 Corvette?

The C7 has the following power graph:



And a chassis dyno result:



Using this video, we see that they shift at 6500rpm and then drops to around 4500rpm for the next gear:

Let's do a simple calculation of the average power the C7 engine provides over that rpm range (average power in a gear is what determines acceleration and thereby trap speed, not a peak hp number only available for 100rpm...):

As we can see from the chassis dyno, the power drops after 6000rpm. At 6500rpm the power is at the same level as it was at 5000rpm, which seems to be around 420hp on the official dyno graph.

Since the power graph seems to have a very similar curved shape before and after 6000rpm, we can do a simplified calculation of average power for the 5500-6500rpm range:

(420+460+420)/3 = 433hp

(Note that we ideally should have used more data points to calculate a truer representative of average power here, since the graph is curved. The simplified method with only three data points underestimates average power in this case)

But as we noticed the engine RPMs dropped to 4500rpm with each gear shift, so we also need to add that to our (simplified) calculation of average power from 4500-6500rpm:

At 4500rpm the C7 engine seems to be roughly around the 380hp mark (on the official C7 factory graph).

Assuming a fairly linear power curve from 4500-5000rpm gives us the following total average power calculation:

380+420/2 = 400hp (average from 4500-5000rpm)

Total average from 4500-6500:

400+433/2 = 416hp

So, as we can see, the C7 has around 416hp in average power from 4500-6500rpm, which is the rev band used under acceleration (based on the video).

We all know that the S55 is claimed to have a average power of 425hp from 5500-7300rpm.

To me it makes sense that the M3/4 and C7 both record trap speeds of around 117-118MPH, when their average power under acceleration is 416hp vs 425hp and where the C7 has a lower weight to compensate for it's 9hp lower average hp.

If the F8x REALLY has the power these dyno results indicate, then the trap speeds should be considerably higher than the C7. Because if the 425whp is to believed, then the S55 needs to make around 470-480 at the crank. A car that has a engine that makes an average of 470-480hp in each gear, should annihiliate a C7 that only has around 410-420hp in average. That simply doesn't add up (unless the F8x starts trapping well over the 120MPH mark of course ).

In addition I would also say that if the S55 is under rated, it most likely isn't by more than the 5% allowed for by EU legislation (425 x 1,05 still is 446hp and a substantial increase by all means)

[mike@x-ph.com]

Good numbers

[dmk08]

Originally Posted by Boss330

Then why don't we see higher trap speeds than for instance the C7 Corvette?

The C7 has the following power graph:



Let's do a simple calculation of the average power the C7 engine provides over that rpm range (average power in a gear is what determines acceleration and thereby trap speed, not a peak hp number only available for 100rpm...):

As we can see from the chassis dyno, the power drops after 6000rpm. At 6500rpm the power is at the same level as it was at 5000rpm, which seems to be around 420hp on the official dyno graph.

Since the power graph seems to have a very similar curved shape before and after 6000rpm, we can easily do a simplified calculation of average power for the 5500-6500rpm range:

(420+460+420)/3 = 433hp

But as we noticed the engine RPMs dropped to 4500rpm with each gear shift, so we also need to add that to our (simplified) calculation of average power from 4500-6500rpm:

At 4500rpm the C7 engine seems to be roughly around the 380hp mark (on the official C7 factory graph).

Assuming a fairly linear power curve from 4500-5000rpm gives us the following total average power calculation:

380+420/2 = 400hp (average from 4500-5000rpm)

Total average from 4500-6500:

400+433/2 = 416hp

So, as we can see, the C7 has around 416hp in average power from 4500-6500rpm, which is the rev band used under acceleration (based on the video).

We all know that the S55 is claimed to have a average power of 425hp from 5500-7300rpm.

To me it makes sense that the M3/4 and C7 both record trap speeds of around 117-118MPH, when their average power under acceleration is 416hp vs 425hp and where the C7 has a lower weight to compensate for it's 9hp lower average hp.

If the F8x REALLY has the power these dyno results indicate, then the trap speeds should be considerably higher than the C7. Because if the 425whp is to believed, then the S55 needs to make around 470-480 at the crank. A car that has a engine that makes an average of 470-480hp in each gear, should annihiliate a C7 that only has around 410-420hp in average. That simply doesn't add up (unless the F8x starts trapping well over the 120MPH mark of course ).

In addition I would also say that if the S55 is under rated, it most likely isn't by more than the 5% allowed for by EU legislation (425 x 1,05 still is 446hp and a substantial increase by all means)

Dynolab is a reputable dyno. It's actually known as a heartbreaker in many cases. So 425 seems pretty legit.

Isn't the vettes real weight only around 3290lb? Couldn't that account for a good bit of this?

[JoeFromPA]

Boss,

Serious quesiton, didn't you just jump between wheel hp and crank hp claims at the end of that post?

Also, are you taking into account actual wheel torque AS MEASURED BY GEARING through 1st-3rd or 1st-4th gears for both vehicles? I mean, it's not like they are putting down the same wheel torque/HP numbers in each gear - gearing has to be taken into account.

Also, air resistance of both vehicles? Also, isn't the C7 more effectively putting down power between the gear change in the lower gear due to tire differences? This may only impact 1st and 2nd.

[Boss330]

Originally Posted by JoeFromPA

Boss,

Serious quesiton, didn't you just jump between wheel hp and crank hp claims at the end of that post?

Also, are you taking into account actual wheel torque AS MEASURED BY GEARING through 1st-3rd or 1st-4th gears for both vehicles? I mean, it's not like they are putting down the same wheel torque/HP numbers in each gear - gearing has to be taken into account.

Also, air resistance of both vehicles? Also, isn't the C7 more effectively putting down power between the gear change in the lower gear due to tire differences? This may only impact 1st and 2nd.

I have looked through my post and assume you meant the final paragraph where I talked about the 425whp measured on the dyno in the OP?

I can't see that I jumped between whp and crank hp there

What I tried to say ( ) was that if the car truly generates 425whp, that would equate to roughly 470-480hp at the crank (with a low 10-12% drivetrain loss). That's the only place in that last paragraph where I mentioned whp to crank hp

Further I pointed out (or at least tried to do ) that if the S55 really has 470-480hp at the crank (which it then has from 5500-7300rpm), also means that the S55 has an average power output in each gear of 470-480hp (the beauty of the S55 plateau power curve).

Agree so far?

My final point then was that I don't quite understand how a car with 470-480 average hp at the crank, traps at a similar trap speed as the C7, which only has 410-420 average hp at the crank (in both cases hp at the crank obviously).

A engine that has around 60-70 more average hp, should trap higher than the C7 (also taking weight difference etc into consideration).

I hope this clarifies what I am trying to make a point about here?

I would welcome any constructive criticism here though. As is often the case, one becomes so immersed in one way of looking at a problem/ challenge, that one doesn't see the forest for all the trees

[A418t81]

The dyno doesn't lie. This is one of the most commonly used dynos in the SouthEast US, and is somewhat of a standard. Lots of cars are on it. Using a Corvette for comparison purposes is comparing apples and oranges. Corvettes always do well for the power they make. My Z06 made 430 whp on a DJ stock, and would run away from 125+ mph cars on a roll. It trapped 124. None of this means anything in regards to the S55 being underrated, however.

Frankly, I think it is silly that you guys would even try to deny the fact that it ISNT underrated with such blatant dyno evidence from coming in from across the freaking country.

[Boss330]

Originally Posted by dmk08

Dynolab is a reputable dyno. It's actually known as a heartbreaker in many cases. So 425 seems pretty legit.

Isn't the vettes real weight only around 3290lb? Couldn't that account for a good bit of this?

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

I zeroed the scales and levelled them with a self-leveling Dewalt laser line tool to eliminate any offset in the corner weights.

Curb weight : 3411 lbs (1547 kg) with all fluids full

Corner weights:

LF: 812 lbs
RF: 890 lbs
LR: 882 lbs
RR: 827 lbs

Total front: 1702 lbs or 49.9%
Total rear: 1708 lbs or 50.1 %
Total cross (LF + RR): 1639 lbs or 48.8%
Total right:1717 lbs or 50.3%

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.

[Boss330]

Originally Posted by A418t81

The dyno doesn't lie.

Seriously?

How do we then explain the 15% variation from the same brand/type of dyno from shop to shop. Or why the S65 usually seems to underperform on the dyno and pull timing etc?

On the chassis dyno we have seen anywhere from 365whp to 430whp, from the same S55 engine. Surely that isn't exactly evidence of reliable and verifiable data acquisition?

Trap speed is a better measure of real world performance data, since the variables of dyno operation, calibration and conditions in the dyno room are out of the equation.

BTW, C&D recorded a 116MPH trap speed for the M4 today:

http://www.caranddriver.com/reviews/...ed-test-review

[bruce.augenstein@comcast.]

Originally Posted by A418t81

1300 miles. Broken in on the Nurburgring, SPA, and the Autobahn.

Bone stock, 93 octane. 86 deg, 55% humidity. This was a hot dyno run. I made a pull about 30 seconds earlier, but something weirded the car out and power numbers were low. Slowed the drum down and immediately made another pull.

All I have to say is you people can run your silly computer simulations all day long. The car is making a lot more than 430 crank hp. The S65 powered cars on this dyno make 355-365 whp. He has dyno'd over 5000 cars on this dyno.

Power feels great. Pulls hard all the way to 7500 rpm by the butt dyno which is confirmed here. Again, those saying it noses over around 6500 need to recalibrate their butt dynos. 400+ whp for around 2k rpm power plateau. Awesome

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.

[Alex07M3]

Originally Posted by Boss330

Seriously?

How do we then explain the 15% variation from the same brand/type of dyno from shop to shop. Or why the S65 usually seems to underperform on the dyno and pull timing etc?

On the chassis dyno we have seen anywhere from 365whp to 430whp, from the same S55 engine. Surely that isn't exactly evidence of reliable and verifiable data acquisition?

Trap speed is a better measure of real world performance data, since the variables of dyno operation, calibration and conditions in the dyno room are out of the equation.

BTW, C&D recorded a 116MPH trap speed for the M4 today:

http://www.caranddriver.com/reviews/...ed-test-review

But that M4 is a FULLY loaded with manuat tranny, that can explain the lower trap speed compared to what we have seen before, just saying.

[m3rxn]

beast