[OrangeCrush]

Originally Posted by CanAutM3

Didn't know a stock N55 could rev all the way to ~7500RPM...

Good catch. I didn't even notice this. What is going on here? @TuningTechFS

[FogCityM3]

Thread reeks of insecurities. Shows what happens when some people leave the safe echo-chamber of M4 post and put out their assertions in front of others with a broader perspective. Assuming the dyno numbers are correct, means the M2 chassis is outperforming its engine. Begs the question, is the M4 a good match of chassis and engine/power and did BMW make the best car that it could with the M4 given the extremely close performance of the M2 on shorter tracks with tighter turns?

Originally Posted by technik330

... all these reviews calling the M2 very quick / fast and suddenly one dyno result is enough to cause a wave of doubt, is this even real life?

I can't recount a single review where we see the M2 being driven and then see the presenter walking away and saying: "Damn, I want an M235i".

If anything they're quick to point out this car is on the heels of its bigger brother/sister (for the ladies).

[zenmaster]

Originally Posted by M3816

The dyno is set to read with in 10hp of a dyno jet. It is a tuner dyno similar to dyno dynamics with lots of control for live tuning. Dynocom costs about 120k and dynojet costs about 40k to put it in perspective.

Do you mean 10%? Cause that'd be odd. I though the Dyno Dynamics was actually cheaper than a Dynojet.

[zenmaster]

Originally Posted by M3816

I will post a proper review of the car soon. It did 331 whp 326wtq 3 passes back to back and 360whp 336 wtq after custom ecu tune. The car was not removed off the dyno and it was the same gas and operator. I have a few mods done already too may be I will do a journal instead.

ps the car factory exhaust note owns the s55 stock exhaust by a mile!

Those stock numbers are as expected, but tune is a little conservative compared to typical 135/235/335 piggyback numbers with torque being rather low comparatively.
+34 HP, +10 TQ can be achieved merely by changing MAF sensor readings.

http://www.e90post.com/forums/showpo...38&postcount=1

[zenmaster]

What dyno did you use M3816?

[PrematureApex]

Originally Posted by OrangeCrush

To me it looks like the power is shifted to the right when compared to a standard N55.

I agree. At least the older pneumatic wastegated N55s. Mine is on it's face by 5.5-6k. I think the F series+ held power a bit longer, but I didn't think as much as we're seeing there.

Could very well be at least a new compressor wheel...

Time will tell. But the fact that it holds power closer to redline is a good trait to have in an M car, for sure.

[Boss330]

Originally Posted by zenmaster

Yes att that RPM, looks as expected. The only thing that looks weird is everything after that

Are you saying the kW vs Nm curves aren't mathematically correct? I'm pretty sure that if you take any given rpm point and calculate the kW from the Nm it will match the BMW graph perfectly...

As said before. Dyno testing on an engine dyno (and on Advanced chassis dynos like the MAHA) allows testing to be done in steady state, instead of transient state. This means that the engine is stabilized at each rpm point where measurements are taken. So the engine is running at, say a constant 4000rpm, output is measured. Then at 4500rpm engine rpm is stabilized once again and output measured. And so on and so on.

This means that the curves usually are smoother and have less spikes. A chassis dyno with poor air flow and cooling for the car creates all sorts of issues the DME has to adjust for. Power graphs from chassis dyno tests often look more ragged than a steady state engine dyno test.

Of course, I assume BMW also applies smoothing to their published graphs. It probably isn't as smooth as on the published graph from BMW in reality, even in steady state testing.

[OrangeCrush]

Originally Posted by Boss330

Are you saying the kW vs Nm curves aren't mathematically correct? I'm pretty sure that if you take any given rpm point and calculate the kW from the Nm it will match the BMW graph perfectly...

As said before. Dyno testing on an engine dyno (and on Advanced chassis dynos like the MAHA) allows testing to be done in steady state, instead of transient state. This means that the engine is stabilized at each rpm point where measurements are taken. So the engine is running at, say a constant 4000rpm, output is measured. Then at 4500rpm engine rpm is stabilized once again and output measured. And so on and so on.

This means that the curves usually are smoother and have less spikes. A chassis dyno with poor air flow and cooling for the car creates all sorts of issues the DME has to adjust for. Power graphs from chassis dyno tests often look more ragged than a steady state engine dyno test.

Of course, I assume BMW also applies smoothing to their published graphs. It probably isn't as smooth as on the published graph from BMW in reality, even in steady state testing.

I think he's just talking about the results in general, not the torque to hp calculation. Look at how everything flattens out or even drops after 4500 rpms.

[Boss330]

Originally Posted by OrangeCrush

I think he's just talking about the results in general, not the torque to hp calculation. Look at how everything flattens out or even drops after 4500 rpms.

That's how a turbo motor works, especially a modern BMW M turbo engine. Same takes place on the S55 and to a lesser extent, the S63.

Torque tapers towards the end of the rpm scale in order to keep hp at a constant level. Also because of flow limitations for the turbo, but that is usually only relevant with tuning.

[raysspl]

Very interesting...

[hoyasaxa]

Originally Posted by M3816

I will post a proper review of the car soon. It did 331 whp 326wtq 3 passes back to back and 360whp 336 wtq after custom ecu tune. The car was not removed off the dyno and it was the same gas and operator. I have a few mods done already too may be I will do a journal instead.



ps the car factory exhaust note owns the s55 stock exhaust by a mile!

That stock TQ number seems low, doesn't it, considering the over boost feature? Shrug.

[M3816]

Originally Posted by zenmaster

Those stock numbers are as expected, but tune is a little conservative compared to typical 135/235/335 piggyback numbers with torque being rather low comparatively.
+34 HP, +10 TQ can be achieved merely by changing MAF sensor readings.

http://www.e90post.com/forums/showpo...38&postcount=1

Originally Posted by OrangeCrush

Nice, thanks! Can you tell if there is more room left in the turbo?

Yes there is more power to be had, we put the car on the dyno with about 30 miles may be less, the motor needs to seal before I go ape shit and for max power. I am sure everyone waiting for their car can understand and cares about the longevity of their M2 as I do. Heck 90% of people don't have the heart to even do a ecu tune so early on!

Originally Posted by FrankM4

Your car looks great BTW! Black BEAST!!!

Thanks bro

Originally Posted by CanAutM3

Didn't know a stock N55 could rev all the way to ~7500RPM...

Originally Posted by OrangeCrush

Good catch. I didn't even notice this. What is going on here? @TuningTechFS

The rpm is calculated by roller revolutions. The car is not reving to 7500, that should be obvious given the power dropping so hard. Bare in mind guys the car was bought at 9pm and the tuning was finished by about 2:30 am with a show to be hosted the next day and all the excitement of the new toy, linking OBD 2 and making sure we are collecting forum data was truly not something we were considering.

TTFS hosted a dyno day at 8 am and I know there was plenty of other cars that were dynoed. I hope that helps explain things a little.

Originally Posted by zenmaster

Do you mean 10%? Cause that'd be odd. I though the Dyno Dynamics was actually cheaper than a Dynojet.

There are many different version of dynojet and dyno dynamics and dyno-com and so on. But if you are keeping it models with the same features in mind, Dyno Dynamics and Dyno Com are much pricier compared to Dynojet. Frank has owned 2 Mustang Dynos, 3 Dynojet in FL and a dyno dynamics prior to the current Dyno Com in MD . The dynocom was calibrated vs a local dynojet with in 2-3 miles from TTFS. The engineer from Dynocom was forced to fly out to MD.

Here is a little food for thought when comparing the dyno numbers to a dynojet. This guy went to 2 dynos on the west coast, and came to ours and was within 10hp.

http://www.m3forum.net/m3forum/showp...65&postcount=1

The dyno number is pointless until the car is out on the strip putting some mile an hour as I am sure you know

[CanAutM3]

Originally Posted by M3816

The rpm is calculated by roller revolutions. The car is not reving to 7500, that should be obvious given the power dropping so hard. Bare in mind guys the car was bought at 9pm and the tuning was finished by about 2:30 am with a show to be hosted the next day and all the excitement of the new toy, linking OBD 2 and making sure we are collecting forum data was truly not something we were considering.

Thanks for the explanation.

I am curious though, how did the dyno figure RPM? Did you have to enter rolling radius and gearing? Wouldn't it be simpler to just plot power vs mph?

With the RPM being off, it also implies the torque calculation is not representative/accurate.

Originally Posted by M3816

The dyno number is pointless until the car is out on the strip putting some mile an hour as I am sure you know

[FSociety]

Why tune an M2 that hasn't even been broken in ?
the 365/340 looks more baseline if anything (looking at the dyno they both have same boost)

[M3816]

Originally Posted by CanAutM3

Thanks for the explanation.

I am curious though, how did the dyno figure RPM? Did you have to enter rolling radius and gearing? Wouldn't it be simpler to just plot power vs mph?

With the RPM being off, it also implies the torque calculation is not representative/accurate.

We are going to get it on the dyno again, hopefully this weekend, this time for data, I was really looking forward to washing and sealing the paint of the car this weekend, oh well.

Originally Posted by ROBNYC

Why tune an M2 that hasn't even been broken in ?
the 365/340 looks more baseline if anything (looking at the dyno they both have same boost)

Are you trolling ?Why buy a BMW when a NYC taxi is good enough ? You do realize the boost gauge was not connected right ? But I am happy you know so much about the expected baseline of a platform that is still being tested by everyone.

[CosmosMpower]

Originally Posted by jawwadh

right, it doesn't, as the m4 is severely undertired from the factory and has issues putting power down. Slap some tires worth their weight and watch the what happens.

THe m2 is nice but there is some hardcore penis envy against the m4..

Motor trend video said 107.6 vs 116.5 1/4 mile trap which is a huge difference.

[OrangeCrush]

Originally Posted by CosmosMpower

Motor trend video said 107.6 vs 116.5 1/4 mile trap which is a huge difference.

107 is slower than the M235i.

[CosmosMpower]

Originally Posted by OrangeCrush

107 is slower than the M235i.

Might be a typo but that's sad if it's true. Should be low teens.

[OrangeCrush]

Originally Posted by CosmosMpower

Might be a typo but that's sad if it's true. Should be low teens.

Car and driver got 12.7@113 in a manual M2. The exact time and mph as a 2014 911. That same issue they got 12.1@119 for a DCT M4. What does it all mean? Nothing. We will start seeing time slips for the M2 soon enough.

And I agree, if the M2 does 107 it would be sad...but if it's really that slow then it must have the best chassis in the world to be able to hang with the M4 at the track.

[CosmosMpower]

Originally Posted by OrangeCrush

Car and driver got 12.7@113 in a manual M2. The exact time and mph as a 2014 911. That same issue they got 12.1@119 for a DCT M4. What does it all mean? Nothing. We will start seeing time slips for the M2 soon enough.

And I agree, if the M2 does 107 it would be sad...but if it's really that slow then it must have the best chassis in the world to be able to hang with the M4 at the track.

113 and 119 both seem a tiny bit high (1-2mph) but the gap is correct. If you watch the MT video the M4 is actually in the lead until the last few tight corners where the m2 remains more stable coming on to the long straight and inches ahead even though the M4 crosses the line with a much higher speed. Also we have no idea what tires and the condition of them on both cars. Overall I think the M4 will be faster by quite a bit at big tracks like VIR, COTA, Road Atlanta due to the extra power indicated by a 6 mph higher trap.

[hoyasaxa]

Originally Posted by CosmosMpower

Might be a typo but that's sad if it's true. Should be low teens.

Was the M235 the 8AT? Could be part of it ... But not a good sign regardless.

[Robin_NL]

Originally Posted by CosmosMpower

113 and 119 both seem a tiny bit high (1-2mph) but the gap is correct. If you watch the MT video the M4 is actually in the lead until the last few tight corners where the m2 remains more stable coming on to the long straight and inches ahead even though the M4 crosses the line with a much higher speed. Also we have no idea what tires and the condition of them on both cars. Overall I think the M4 will be faster by quite a bit at big tracks like VIR, COTA, Road Atlanta due to the extra power indicated by a 6 mph higher trap.

M2 did do 7:52 at the Nordschleife though BMW obviously wants M3/4 to stay King so they stated 7:58 as the official (repeatable) laptime...

It's all about (driving) dynamics.

Cheers
Robin