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09-18-2014, 10:08 AM | #1 |
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Compilation of MAHA dyno results from Sport Auto Supertest
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... Last edited by Boss330; 09-18-2014 at 10:18 AM.. |
09-18-2014, 10:38 AM | #3 |
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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.
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09-18-2014, 10:42 AM | #4 |
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Thanks for sharing .
Very interreesting data points . |
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09-20-2014, 03:01 PM | #5 |
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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... Last edited by Boss330; 09-20-2014 at 03:11 PM.. |
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09-21-2014, 04:19 AM | #6 |
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BORLA Development car on a Dynojet:
http://f80.bimmerpost.com/forums/sho....php?t=1034354 Stock baseline (before new exhaust) 385whp (SAE): |
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09-21-2014, 06:16 AM | #7 | |
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09-21-2014, 07:29 AM | #8 |
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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). |
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09-21-2014, 07:59 AM | #9 | |
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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. Last edited by CanAutM3; 09-21-2014 at 08:19 AM.. |
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09-21-2014, 10:25 AM | #10 | ||
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09-21-2014, 10:36 AM | #11 | |
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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 . Last edited by CanAutM3; 09-21-2014 at 10:41 AM.. |
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09-21-2014, 11:05 AM | #12 | ||
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09-21-2014, 12:12 PM | #13 | |
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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. |
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09-21-2014, 12:15 PM | #14 |
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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.
Last edited by CanAutM3; 09-21-2014 at 12:27 PM.. |
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09-21-2014, 12:52 PM | #15 | ||
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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? Quote:
Last edited by Boss330; 09-21-2014 at 01:15 PM.. |
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09-21-2014, 02:34 PM | #16 | |
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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. |
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09-21-2014, 02:52 PM | #17 | |
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If not, this dyno seems to have a major flaw when measuring any 2wd car... |
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09-21-2014, 03:08 PM | #18 | |
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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. |
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09-21-2014, 03:14 PM | #19 | ||
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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. |
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09-21-2014, 03:52 PM | #20 | |
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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. Last edited by CanAutM3; 09-21-2014 at 08:08 PM.. |
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09-21-2014, 06:21 PM | #21 | ||
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YES! If you want to prove power you should post either a time slip, or a time slip. Or a time slip. Last edited by turbo8765; 09-21-2014 at 06:41 PM.. |
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09-21-2014, 08:06 PM | #22 |
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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.
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