First BMW M4 GTS dyno = 492hp at crank

[Boss330]

The video was posted last week:

http://f80.bimmerpost.com/forums/sho....php?t=1270153


BMW says 500Ps, this dyno run shows 492Ps

Seems quite spot on to me...

[Rasya]

Originally Posted by Boss330

The video was posted last week:

http://f80.bimmerpost.com/forums/sho....php?t=1270153


BMW says 500Ps, this dyno run shows 492Ps

Seems quite spot on to me...

Sorry to repost, didn't check that section.

BMW rates 500ps at the crank, but it dynos almost that amount at the WHEELS, which equals to 552ps at the crank

[Boss330]

Originally Posted by Rasya

Sorry to repost, didn't check that section.

BMW rates 500ps at the crank, but it dynos almost that amount at the WHEELS, which equals to 552ps at the crank

Read the dyno graph again. It says 492PS at "kupplung".

Kupplung is German for clutch, so it has 492PS on the flywheel (or clutch to use the German term). Again, pretty spot on to the official factory figure.

The peak at the extreme end of the chart is due to the gearchange at the end of the run, so the peak value is wrong. It's also explained previously in this thread by a member who was there during the dyno run.


How accurate the dyno numbers are is a different question though, but usually Dynojets read high and not low...

[VCP]

A simple equation is Dynojet reads close to crank HP/PS and Mustang, Dyno Dynamics (Load cell Dynos) read wheel HP/PS

Originally Posted by Boss330

Read the dyno graph again. It says 492PS at "kupplung".

Kupplung is German for clutch, so it has 492PS on the flywheel (or clutch to use the German term). Again, pretty spot on to the official factory figure.

The peak at the extreme end of the chart is due to the gearchange at the end of the run, so the peak value is wrong. It's also explained previously in this thread by a member who was there during the dyno run.


How accurate the dyno numbers are is a different question though, but usually Dynojets read high and not low...

[Boss330]

Originally Posted by VCP

A simple equation is Dynojet reads close to crank HP/PS and Mustang, Dyno Dynamics (Load cell Dynos) read wheel HP/PS

To clarify. What you are saying is that a Dynojet WHP number is closer to the crank number (since they tend to read high), right?

[VCP]

Yes. The others will factor a reading to be close to Dynojet for bragging rights. From a tuning/diagnosing point I feel the dynojet is useless. I do own a Dyno Dynamics though LOL

Originally Posted by Boss330

To clarify. What you are saying is that a Dynojet WHP number is closer to the crank number (since they tend to read high), right?

[goj]

Something doesn't add up here to me. You should compare this to a standard M4 on the same dyno to get a proper delta. Between the two models

[Phatcat]

Originally Posted by goj

Something doesn't add up here to me. You should compare this to a standard M4 on the same dyno to get a proper delta. Between the two models

Yeah, should run a M4 at the same time.

[VCP]

First thing, get off that Dynojet.

Originally Posted by goj

Something doesn't add up here to me. You should compare this to a standard M4 on the same dyno to get a proper delta. Between the two models

[goj]

Originally Posted by VCP

First thing, get off that Dynojet.

I mean I'm just curious to see the % difference in power between the stock M4 S55 and the GTS motor with water injection.

Not looking for actual numbers because like you said a DynoJet isn't good for that

[VCP]

I am sure it will happen before, but my GTS will be here within 3 weeks. I am going to do back to back runs against my M4 so I have same conditions for both. Should be fun! To my butt dyno, after 3400kms on the GTS it really does feel like a healthy 500HP, maybe even 500WHP. It takes HP to get to 300km/hr as quickly as the GTS did for me.

Originally Posted by goj

I mean I'm just curious to see the % difference in power between the stock M4 S55 and the GTS motor with water injection.

Not looking for actual numbers because like you said a DynoJet isn't good for that

[goj]

Originally Posted by VCP

I am sure it will happen before, but my GTS will be here within 3 weeks. I am going to do back to back runs against my M4 so I have same conditions for both. Should be fun! To my butt dyno, after 3400kms on the GTS it really does feel like a healthy 500HP, maybe even 500WHP. It takes HP to get to 300km/hr as quickly as the GTS did for me.

Also interesting is that the 'ring lap time it has puts it in serious territory. The 562hp 458 italia was a few milliseconds slower. I know theres different drivers and its NA vs Turbo charged but on a long track 70 extra horses should manifest in some sort of time difference favoring the 458. I personally think that the gap is smaller than "as advertised' with the GTS making over 500. That would make them more evenly matched and time differences would be attributed to the driver/weather etc.

OF COURSE i can't make any absolute conclusions about 2 very different cars running 7 years apart, but a 70 horsepower advantage and a neutral mid engine setup should favor the 458....unless power is closer to equal and the M4 GTS is able to put it down more effectively with its transmission and power/torque curves.

Just my 2 cents, definitely not saying I'm correct here but trying to think logically

[Flying Ace]

meth is hell of a drug.

[CanAutM3]

Originally Posted by VCP

I am sure it will happen before, but my GTS will be here within 3 weeks. I am going to do back to back runs against my M4 so I have same conditions for both. Should be fun! To my butt dyno, after 3400kms on the GTS it really does feel like a healthy 500HP, maybe even 500WHP. It takes HP to get to 300km/hr as quickly as the GTS did for me.

Looking forward to the results

[Captain Unknown GT4]

1. 458 is not developed On the Nurburgring. Thats a major factor, GTS is. And more importent its laptime is set by a guy that know the track(racing there) as well BMW chassi guy.
2. Track is faster faster today than 7 years ago. Very much so @flugplatz-SwedenX and that is One of five 200+ kmh section on Nur.
3. GTS is on modern tech MPSC tire.
4. As you mention, different drivers. Thats a major factor on Nurburgring.

[goj]

1. Many cars weren't developed on the ring. Didn't seem to hurt the Nissan GT-R.
2. I'm sure the tires on the car were excellent regardless. Especially for the official Lap time.
3. Yes different driver but I'm sure he was very familiar with the ring.
4. The Ferrari has all advantages on paper.

[Captain Unknown GT4]

To my knowlede GT-R was just that, developed very much on the Nurburgring. At the same time nissan was lappning the Porsche turbo. We all know what happend, GT-R would never been that fast on nur if not developed heavy there as well.
I am not sure who drove the Ferrari, but if you guys refer to sport auto lap thats no not always a god way to compare to Factory lap. As sport auto 7 years ago was HvS and he was pretty fast to get a lot out of a car, but only drove a few laps to set time. At times he was 3 seconds of Factory times, but other times several more seconds of.
To my know how Ferrari dont do Factory lap times on Nurburgring.

So sure, this could be a factor to remember vs M4 GTS.

[Maltman]

Originally Posted by Mike@N54Tuning.com

Have you ran a regular M3/M4 on this dyno for comparison?

Mike

Yes we did. Stock M4 MT6

[Boss330]

We also have a second dyno result for the M4 GTS now. The Auto Bild Sportscars Supertest of the GTS also has 492PS at the flywheel.

So, two 492PS at the flywheel results so far.

Auto Bild measured the M4 to 449PS (although they mention that it in reality should be 18PS lower but for a short peak in the power curve)

The above numbers from Auto Bild is allmost identical to the dyno numbers posted in this thread.

M4 GTS: 492PS (BBM and Auto Bild)
M4: 448/449PS (BBM/Auto Bild)

[FC4]

Originally Posted by Boss330

We also have a second dyno result for the M4 GTS now. The Auto Bild Sportscars Supertest of the GTS also has 492PS at the flywheel.

Actually, no...no one has measured a GTS' power at the flywheel yet.

[StatenEye]

Originally Posted by Phatcat

Yeah, should run a M4 at the same time.

Ill never get used to the term M4.

[CanAutM3]

Originally Posted by FC4

Actually, no...no one has measured a GTS' power at the flywheel yet.

While it is true that there is no known GTS S55 that has been bench tested with power measured at the "flywheel", all the numbers posted so far do seem to be "at the crank" and not at the wheels.