Clutch Slip or Wet road in logs creating inflated HP/TQ numbers with Virtual Dyno?
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Clutch Slip or Wet road in logs creating inflated HP/TQ numbers with Virtual Dyno?
This may be a stupid question but I searched and can't find anything about this.
1st of all I have no reason to believe that my clutch is slipping. I have had worn clutches and have experience a clutch slipping badly.
I'm trying to figure out why the 2 WOT runs I did this morning have my HP/TQ numbers on Virtual Dyno about 75-100 higher.
Same exact stretch of road that I log all my runs. Similar temperature, weight....blah, blah. All that stuff.
But doesn;t the dyno software just use time vs. rpm to calculate HP/TQ?
I dont log vehicle speed but in the logs I don't see any spots where the rpms rise faster than normal.
The only thing I can think is if the clutch were slipping or the road was wet (which it was) maybe then the RPMS would rise faster than they would normally.
But if this were the case wouldn't the logged LOAD be affected. Which it's not.
Just can't figure it out.
Here is a log that has normal HP/TQ #s. Same everything.
And the log that's giving me ridiculous #'s
Does anything stand out to you guys that would make these 2 logs that different?
Same car, driver, temp, day, road...everything.
1st of all I have no reason to believe that my clutch is slipping. I have had worn clutches and have experience a clutch slipping badly.
I'm trying to figure out why the 2 WOT runs I did this morning have my HP/TQ numbers on Virtual Dyno about 75-100 higher.
Same exact stretch of road that I log all my runs. Similar temperature, weight....blah, blah. All that stuff.
But doesn;t the dyno software just use time vs. rpm to calculate HP/TQ?
I dont log vehicle speed but in the logs I don't see any spots where the rpms rise faster than normal.
The only thing I can think is if the clutch were slipping or the road was wet (which it was) maybe then the RPMS would rise faster than they would normally.
But if this were the case wouldn't the logged LOAD be affected. Which it's not.
Just can't figure it out.
Here is a log that has normal HP/TQ #s. Same everything.
LogEntrySeconds | TPS | RPM | Timing | A/F | LOAD |
0.22301 | 100 | 2750 | 13 | 12.9 | 118.125 |
0.31339 | 100 | 2781.25 | 11 | 12.8 | 121.875 |
0.4578 | 100 | 2812.5 | 11 | 12.5 | 126.5625 |
0.57143 | 100 | 2843.75 | 10 | 12.5 | 130.625 |
0.67611 | 100 | 2937.5 | 11 | 12.6 | 136.25 |
0.7733 | 100 | 2968.75 | 10 | 12.5 | 142.1875 |
0.88186 | 100 | 3031.25 | 9 | 12.4 | 148.125 |
0.99293 | 100 | 3093.75 | 9 | 12.4 | 155.625 |
1.10912 | 100 | 3156.25 | 8 | 12.6 | 167.1875 |
1.2213 | 100 | 3218.75 | 8 | 12.6 | 178.75 |
1.33598 | 100 | 3312.5 | 7 | 12.3 | 195.9375 |
1.47512 | 100 | 3375 | 7 | 12.1 | 210.9375 |
1.61092 | 100 | 3468.75 | 7 | 12.1 | 225.9375 |
1.93744 | 100 | 3531.25 | 6 | 11.8 | 242.1875 |
2.06113 | 100 | 3593.75 | 6 | 11.7 | 263.4375 |
2.18768 | 100 | 3718.75 | 6 | 11.7 | 276.5625 |
2.29494 | 100 | 3812.5 | 6 | 11.3 | 268.125 |
2.39408 | 100 | 3906.25 | 7 | 11.2 | 256.25 |
2.50828 | 100 | 4031.25 | 8 | 11.2 | 254.375 |
2.63163 | 100 | 4156.25 | 8 | 11.2 | 252.8125 |
2.72831 | 100 | 4250 | 9 | 11.6 | 250.625 |
2.83328 | 100 | 4375 | 9 | 11.5 | 255 |
2.94571 | 100 | 4500 | 8 | 11.5 | 258.125 |
3.04874 | 100 | 4625 | 8 | 11.5 | 256.25 |
3.17262 | 100 | 4718.75 | 9 | 11.3 | 253.75 |
3.27808 | 100 | 4812.5 | 10 | 11.3 | 251.25 |
3.39727 | 100 | 4937.5 | 10 | 11.4 | 254.375 |
3.50489 | 100 | 5031.25 | 10 | 11.5 | 259.0625 |
3.61222 | 100 | 5156.25 | 9 | 11.3 | 261.5625 |
3.71549 | 100 | 5250 | 10 | 11.4 | 261.875 |
3.81325 | 100 | 5375 | 10 | 11.4 | 260.3125 |
3.91785 | 100 | 5500 | 11 | 11.4 | 259.6875 |
4.01507 | 100 | 5593.75 | 11 | 11.5 | 258.75 |
4.12261 | 100 | 5718.75 | 11 | 11.5 | 257.8125 |
4.23894 | 100 | 5812.5 | 12 | 11.4 | 255.9375 |
4.34331 | 100 | 5906.25 | 12 | 11.6 | 252.1875 |
4.4453 | 100 | 6031.25 | 12 | 11.7 | 250.3125 |
4.57239 | 100 | 6125 | 13 | 11.7 | 249.6875 |
4.68596 | 100 | 6218.75 | 13 | 11.5 | 246.5625 |
4.80761 | 100 | 6343.75 | 13 | 11.5 | 243.4375 |
4.89976 | 100 | 6437.5 | 14 | 11.3 | 241.875 |
5.00666 | 100 | 6531.25 | 14 | 11.3 | 239.375 |
5.12526 | 100 | 6625 | 14 | 11.3 | 237.5 |
5.23447 | 100 | 6718.75 | 14 | 11.3 | 236.25 |
5.33978 | 100 | 6812.5 | 15 | 11.3 | 234.0625 |
5.44579 | 100 | 6906.25 | 15 | 11.3 | 231.875 |
5.55394 | 100 | 7000 | 15 | 11.2 | 230.3125 |
And the log that's giving me ridiculous #'s
Time | TPS | RPM | Timing | A/F | LOAD |
1.02866 | 100 | 2906.25 | 12 | 12.6 | 130 |
1.1585 | 100 | 2937.5 | 11 | 12.5 | 134.6875 |
1.29783 | 100 | 2968.75 | 11 | 12.5 | 140 |
1.43164 | 100 | 3031.25 | 10 | 12.4 | 146.25 |
1.54691 | 100 | 3093.75 | 9 | 12.5 | 154.375 |
1.67182 | 100 | 3125 | 8 | 12.5 | 161.5625 |
1.79412 | 100 | 3156.25 | 7 | 12.6 | 171.5625 |
2.06529 | 100 | 3218.75 | 5 | 12.6 | 180.9375 |
2.20106 | 100 | 3281.25 | 5 | 12.3 | 193.125 |
2.29415 | 100 | 3343.75 | 5 | 12.1 | 209.375 |
2.40319 | 100 | 3406.25 | 4 | 12.1 | 225.3125 |
2.5182 | 100 | 3500 | 4 | 12 | 248.4375 |
2.62782 | 100 | 3562.5 | 3 | 12 | 269.6875 |
2.72113 | 100 | 3656.25 | 4 | 11.8 | 281.875 |
2.81011 | 100 | 3843.75 | 2 | 11.6 | 265 |
2.90024 | 100 | 3968.75 | 3 | 11.4 | 260.625 |
2.99008 | 100 | 4093.75 | 3 | 11.5 | 259.0625 |
3.07694 | 100 | 4187.5 | 3 | 11.8 | 258.125 |
3.16795 | 100 | 4281.25 | 5 | 11.8 | 255 |
3.25511 | 100 | 4375 | 5 | 11.7 | 256.25 |
3.34933 | 100 | 4500 | 5 | 11.6 | 255 |
3.43887 | 100 | 4593.75 | 5 | 11.7 | 256.25 |
3.53701 | 100 | 4750 | 5 | 11.7 | 257.1875 |
3.63203 | 100 | 4843.75 | 6 | 11.7 | 256.875 |
3.72719 | 100 | 4968.75 | 6 | 11.6 | 259.0625 |
3.8246 | 100 | 5125 | 6 | 11.6 | 260.625 |
3.91731 | 100 | 5218.75 | 6 | 11.6 | 263.125 |
4.01226 | 100 | 5343.75 | 7 | 11.6 | 264.0625 |
4.11603 | 100 | 5437.5 | 7 | 11.6 | 263.4375 |
4.20584 | 100 | 5531.25 | 7 | 11.7 | 261.875 |
4.30087 | 100 | 5656.25 | 7 | 11.6 | 262.1875 |
4.40126 | 100 | 5781.25 | 8 | 11.6 | 261.25 |
4.49343 | 100 | 5875 | 8 | 11.8 | 259.0625 |
4.58666 | 100 | 6031.25 | 9 | 11.9 | 254.375 |
4.67824 | 100 | 6093.75 | 9 | 11.6 | 252.1875 |
4.77486 | 100 | 6187.5 | 10 | 11.6 | 250.625 |
4.87062 | 100 | 6312.5 | 10 | 11.6 | 247.1875 |
4.96027 | 100 | 6406.25 | 11 | 11.7 | 243.75 |
5.05725 | 100 | 6500 | 12 | 11.6 | 242.5 |
5.157 | 100 | 6593.75 | 12 | 11.6 | 240.625 |
5.24724 | 100 | 6687.5 | 12 | 11.5 | 237.1875 |
5.33776 | 100 | 6781.25 | 13 | 11.3 | 235.625 |
5.43704 | 100 | 6843.75 | 13 | 11.4 | 233.75 |
5.53203 | 100 | 6968.75 | 13 | 11.4 | 231.5625 |
5.62385 | 100 | 7031.25 | 13 | 11.2 | 229.6875 |
5.722 | 100 | 7093.75 | 13 | 11.2 | 142.8125 |
Does anything stand out to you guys that would make these 2 logs that different?
Same car, driver, temp, day, road...everything.
Last edited by motocooney; Oct 28, 2010 at 10:56 AM.
#2
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If you notice in the 2nd log right around peak torque there's some timing being pulled. There was a knock count there but I've done about 4 runs since this with no knock sum so I think it was a fluke.
That seems to be the only difference between the 2 logs to me. If anything, I'd think the knock in the 2nd log would have potentially made the #'s lower right.
That seems to be the only difference between the 2 logs to me. If anything, I'd think the knock in the 2nd log would have potentially made the #'s lower right.
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I've tried to repeat it and can't.
I honestly think that the road being wet had something to do with it. I wasn't totally spinning out or losing traction. But maybe just enough to make the rpms rise a little bit faster?
Maybe
I honestly think that the road being wet had something to do with it. I wasn't totally spinning out or losing traction. But maybe just enough to make the rpms rise a little bit faster?
Maybe
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This is the graph. Looks normal as far as the shape of the curve just way higher.
I have another one that looks a little more like the one posted above but the weirdness doesn;t happen at peak torque it happens up high in the revs so I thing something was just ****ed up with that run.
I don't know. Its the same stretch of road that I always use.
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