Compilation of MAHA dyno results from Sport Auto Supertest

[Boss330]

I thought it would be interesting to compile a number of MAHA dyno sheets as per Sport Auto Supertest.

I hope this can be of relevance as regards understanding differences between various dyno results and various dynos. As another member here also said, the MAHA LPS 3000, as used in most of the Supertest measurements, is also accepted in German Courts as evidence on engine power. Further, MAHA dynos are also approved by many manufacturers, including BMW, to measure engine performance.

When I started looking at the MAHA dyno sheets in a more systematic and detailed manner, it struck me that the dyno seems to be very close to manufacturer ratings, with two exemptions where the MAHA measured a higher PS rating than manufacturer claims. This was the 991 Turbo S (8% higher) and the M4 (also 8% higher).

Unfortunately, the M4 Supertest doesn't state which type of MAHA dyno that was used, but I will not put any emphasis on that since it in general seems the MAHA consistently gets real close to a real/realistic crank PS number.

As we also have discussed, we had one claimed MAHA result, from the US, at 453PS in the US. We haven't seen a dyno chart for this and we don't know if it was PS or HP, nor which correction factor that was used. But, 465PS is 458HP, so it might have been a MAHA set up for US/imperial HP instead of metric PS. If so, these two results would only be a few HP/PS apart...

[signes]

F12 for me...

Thanks for posting.

[stressdoc]

Nice review! Reminiscent of the real early N54 335 results; I am still convinced that my 335, which was the first one delivered, had a somewhat more 'spirited' program than what was advertised and subsequently modified with software updates.

[CanAutM3]

Thanks for sharing .

Very interreesting data points .

[Boss330]

This shows that a Dynojet so far has between 370whp to 420whp (SAE), a 50whp variation...!!!

93oct, DCT:


93oct, DCT:


Same car as above compared with the owners previous E92 M3:


The last dyno charts haven't been added to the S55 dyno database yet, but was found here:
http://f80.bimmerpost.com/forums/sho...1015581&page=5

It's also woth noting that all of the Dynojet graphs show a short peak in TQ at around 3000rpm, before falling down. This is most likely due to the acceleration run on a dyno takes much less time than it would out on the open road. The engine increases rpm's so fast that the boost management probably doesn't manage to completely "smooth" out the tq curve.

Further it's also noteworthy that both the TQ and HP graphs (regardless of 370whp or 420whp) seems to replicate very well the HP from 5500-7300rpm and TQ to 5500rpm (all chassis dyno runs start from a high(ish) rpm, so we don't see the full TQ curve). It replicates pretty well the average TQ and HP graphs that BMW posted (especially considering the dynamic mode the dyno is run in and not steady state as per engine dyno). Some of the TQ curves show a bit of variation, but could very well be because of the sharp rise in RPMs over a short time span (might also not have torque limiter in the higher gears in the same way it most likely has in the lower gears - Last part here is speculation).


The troubling part must be the variation of 50whp that the Dynojets so far shows for the S55... I won't say anything more about this then say that to me this correlates well with previously observed Dynojet variation. But everyone can decide for themselves if this is the fault of the S55, the Dynojet or measuring techniques...

[Boss330]

BORLA Development car on a Dynojet:

http://f80.bimmerpost.com/forums/sho....php?t=1034354

Stock baseline (before new exhaust) 385whp (SAE):

[gmd2003]

Originally Posted by Boss330

BORLA Development car on a Dynojet:

http://f80.bimmerpost.com/forums/sho....php?t=1034354

Stock baseline (before new exhaust) 385whp (SAE):

Interesting third party non customer dyno's ( Borla, K&N ) are in the 380whp range . Quite simply if the M3/4 had 480 hp like most think, it would perform much better than it has thus far acc wise with its broad power curve DCT and short gearing . It has a 65% shorter first gear than the C7 vette which is rated and has dyno'd at an SAE certified 460hp . Hell the Vettes 1st gear is barely shorter than the C7's 2nd gear . so why isn't the M3/4 significantly faster than the C7 which only weighs 100 pounds less, since it should be with an instant shifting transmission , more power and much shorter gearing ? Bc the M3/4 makes what BMW says it does in the real world, imagine that .

[turbo8765]

If it made the 484 crank that DINAN claimed, it should also outperform an M5 CP DCT.

3580/484 = 7.39
4360/575 = 7.58

So a slight edge in p:w combined with more aggressive gearing (3.46 v 3.15 FD) and better aero (similar Cd (M4-0.34, M5-0.33) but less frontal area).

[CanAutM3]

Originally Posted by gmd2003

Interesting third party non customer dyno's ( Borla, K&N ) are in the 380whp range . Quite simply if the M3/4 had 480 hp like most think, it would perform much better than it has thus far acc wise with its broad power curve DCT and short gearing . It has a 65% shorter first gear than the C7 vette which is rated and has dyno'd at an SAE certified 460hp . Hell the Vettes 1st gear is barely shorter than the C7's 2nd gear . so why isn't the M3/4 significantly faster than the C7 which only weighs 100 pounds less, since it should be with an instant shifting transmission , more power and much shorter gearing ? Bc the M3/4 makes what BMW says it does in the real world, imagine that .

IMO, in the case of the F8X, the super short 1st gear is not optimal. It is so short that it is just not possible to put the power down due to traction limitations.

Also note that the K&N numbers were obtained on a 4WD dyno with all 4 wheels spinning. This will significantly reduce the power output number due to tire losses and inertial impacts of the front axle.

[gmd2003]

Originally Posted by CanAutM3

IMO, in the case of the F8X, the super short 1st gear is not optimal. It is so short that it is just not possible to put the power down due to traction limitations.

Also note that the K&N numbers were obtained on a 4WD dyno with all 4 wheels spinning. This will significantly reduce the power output number due to tire losses and inertial impacts of the front axle.

Just because it is a 4wd dyno doesn't mean the front rollers are engaged . On many including the MAHA the fronts can spin passively to simulate a rolling road ( this prevents many ECU faults on modern cars like ours too ) and has zero impact on power readings . You are making a big mistake assuming the reading is false because of that .

[CanAutM3]

Originally Posted by gmd2003

Just because it is a 4wd dyno doesn't mean the front rollers are engaged . On many including the MAHA the fronts can spin passively to simulate a rolling road ( this prevents many ECU faults on modern cars like ours too ) and has zero impact on power readings . You are making a big mistake assuming the reading is false because of that .

Agreed, if the front rollers are disconnected, there is no impact.

On a Maha dyno, it measures the overall drag. So if all 4 wheels are spinning, the Pschlepp number will take in consideration the increased drag of the front wheels when calculating the crank power number. So I agree, no impact here either.

But specifically, this run on the K&N dyno on the Motortrend show had all 4 wheels spinning on traditional inertia dyno , hence lower numbers. Just have look at the video. So no "big mistake" here .

[gmd2003]

Originally Posted by CanAutM3

Agreed, if the front rollers are disconnected, there is no impact.

On a Maha dyno, it measures the overall drag. So if all 4 wheels are spinning, the Pschlepp number will take in consideration the increased drag of the front wheels when calculating the crank power number. So I agree, no impact here either.

But specifically, this run on the K&N dyno on the Motortrend show had all 4 wheels spinning on traditional inertia dyno , hence lower numbers. Just have look at the video. So no "big mistake" here .

Please show me the link to the video

[bruce.augenstein@comcast.]

Originally Posted by Boss330

..The troubling part must be the variation of 50whp that the Dynojets so far shows for the S55... I won't say anything more about this then say that to me this correlates well with previously observed Dynojet variation. But everyone can decide for themselves if this is the fault of the S55, the Dynojet or measuring techniques...

For me, the Dynojet variation isn't troubling at all. You just pretty much take the higher numbers as more or less "gospel", and ignore the lower numbers. As I've amply demonstrated in Swamp's "Significant recant" thread, setup sloppiness/errors all result in lower observed numbers.

Really the only Dynojet issue is whether the operators ran with ambient meteorological adjustments to their observed numbers, which is a no-no with the current M3/M4, and other current turbo cars as well. You'd think they'd all have gotten the message by now, but perhaps not.

[CanAutM3]

Originally Posted by gmd2003

Please show me the link to the video

See at 5:00. On the F8X run, it is less obvious, but you can see the front rollers spinning underneath the car. On the E9X run, there is a clear shot of the front wheels turning.

[Boss330]

Originally Posted by CanAutM3

See at 5:00. On the F8X run, it is less obvious, but you can see the front rollers spinning underneath the car. On the E9X run, there is a clear shot of the front wheels turning.

According to the video, this is measured on a Superflow dyno:

http://www.superflow.com/Dynamometer...is/880_awd.php

http://www.superflow.com/Dynamometer..._dyn30_awd.php

Seems odd that this kind of dyno must, by design, since the front rollers are mechanically linked and seems not to be clutched, allways measure a wrong WHP reading on a 2wd car?

Differentials and driveshafts allow SuperFlow® to accurately measure and compensate for the parasitic losses of every dyno produced so that each one leaves the factory calibrated with its own inertia and parasitic data. The end result is the most accurate torque and power measurement available.

Surely it must be a really easy software job to eliminate the losses incurred from driving the front rollers when displaying measured whp? Otherwise these dyno's seem to be only useable on a AWD vehicle?

[CanAutM3]

Originally Posted by Boss330

According to the video, this is measured on a Superflow dyno:

http://www.superflow.com/Dynamometer...is/880_awd.php

http://www.superflow.com/Dynamometer..._dyn30_awd.php

Seems odd that this kind of dyno must, by design, since the front rollers are mechanically linked and seems not to be clutched, allways measure a wrong WHP reading on a 2wd car?



Surely it must be a really easy software job to eliminate the losses incurred from driving the front rollers when displaying measured whp? Otherwise these dyno's seem to be only useable on a AWD vehicle?

I am not talking about the power needed to spin the front dyno drum. As mentioned, that power is factored in the dyno calibration.

What I am talking about is the power consumed to overcome the front tire rolling resistance and the inertia of the front wheels, tires and brakes of the car being dynoed.

[Boss330]

Originally Posted by CanAutM3

I am not talking about the power needed to spin the front dyno drum. As mentioned, that power is factored in the dyno calibration.

What I am talking about is the power consumed to overcome the front tire rolling resistance and the inertia of the front wheels, tires and brakes of the car being dynoed.

But wouldn't those losses also be just as easily measured on this type of dyno, for instance when coasting after the run? Surely the dyno must be able to factor in the added losses from the front set of rollers due to the rolling resistance and inertia added to the front drums from those components? Likewise the dyno software must also be able to detect the added rolling resistance etc on the front set of drums under the acceleration run? It knows the inertia and rolling resistance of the drum, and must easily be able to calculate/measure the added resistance from the front wheels?

If not, this dyno seems to have a major flaw when measuring any 2wd car...

[CanAutM3]

Originally Posted by Boss330

But wouldn't those losses also be just as easily measured on this type of dyno, for instance when coasting after the run? Surely the dyno must be able to factor in the added losses from the front set of rollers due to the rolling resistance and inertia added to the front drums from those components? Likewise the dyno software must also be able to detect the added rolling resistance etc on the front set of drums under the acceleration run? It knows the inertia and rolling resistance of the drum, and must easily be able to calculate/measure the added resistance from the front wheels?

If not, this dyno seems to have a major flaw when measuring any 2wd car...

Where do you see tire losses and inertial impacts accounted for any chassis dynos, be it 2WD or 4WD (besides the Maha)?

As I have discussed many time, this is one of the major flaws of chassis dynos.

Note that the same discrepancy exists when running a 4WD car on a 4WD dyno. While it is true that 4WD vehicles have greater drivetrain losses, the effect is exaggerated because all 4 wheels are spinning compared to 2WD vehicle tested on a 2WD dyno.

[Boss330]

Originally Posted by CanAutM3

Where do you see tire losses and inertial impacts accounted for any chassis dynos, be it 2WD or 4WD (besides the Maha)?

As I have discussed many time, this is one of the major flaws of chassis dynos.

Note that the same discrepancy exists when running a 4WD car on a 4WD dyno. While it is true that 4WD vehicles have greater drivetrain losses, the effect is exaggerated because all 4 wheels are spinning compared to 2WD vehicle tested on a 2WD dyno.

This is a subject you know more about than me, but I thought the Superflow AWD dyno had this capability?

http://www.superflow.com/Dynamometer...is/880_awd.php

SuperFlow’s® Road Simulation Technology(RST) utilizes heavy-duty differentials and a steel drive shaft to synchronize the front and rear roll speeds along with eddy-current brakes to accurately load vehicles according to their inertia, aerodynamic losses and rolling losses.

[CanAutM3]

Originally Posted by Boss330

This is a subject you know more about than me, but I thought the Superflow AWD dyno had this capability?

http://www.superflow.com/Dynamometer...is/880_awd.php

SuperFlow’s® Road Simulation Technology(RST) utilizes heavy-duty differentials and a steel drive shaft to synchronize the front and rear roll speeds along with eddy-current brakes to accurately load vehicles according to their inertia, aerodynamic losses and rolling losses.

What I read in this sentence is that because all four wheels are rotated, the dyno factors the entire vehicle inertia when establishing power.

I am not saying that this dyno is less good than others. It simply read differently. I am just saying that the number obtained on this dyno cannot be compared with a 2WD dyno. For instance, if you compare the numbers the E92 put down on the same dyno on the same day, there still is a significant difference between the F8X and the E9X.

Goes back to the statement I have been making since the beginning: absolute wheel power numbers obtained on chassis dynos are pretty much meaningless.

[turbo8765]

Originally Posted by CanAutM3

this run on the K&N dyno on the Motortrend show had all 4 wheels spinning on traditional inertia dyno

They used a super flow. It's an eddy current dyno IIRC.

Originally Posted by bruce.augenstein@comcast.

For me, the Dynojet variation isn't troubling at all. You just pretty much take the higher numbers as more or less "gospel", and ignore the lower numbers.

Tell me about it.

Originally Posted by CanAutM3

chassis dynos are pretty much meaningless.

YES!

If you want to prove power you should post either a time slip, or a time slip.

Or a time slip.

[CanAutM3]

Originally Posted by turbo8765

They used a super flow. It's an eddy current dyno IIRC.

While it is true that this dyno has to ability to operate as a brake dyno, the Motortrend video tends to indicate it was operated as a traditional inertia dyno.

Originally Posted by turbo8765

YES!

If you want to prove power you should post either a time slip, or a time slip.

Or a time slip.