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.

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.

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.

If the clutch was slipping the car would log the rpms faster with less wheel speed.

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:confused:

yeah my friends clutch was slipping and his logs had his torque shooting up like crazy

Here's mine of when my clutch let go.

http://i245.photobucket.com/albums/g...vo%207/VD2.jpg

http://i284.photobucket.com/albums/l...oney/dyno2.png

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.

Smoothing 20?

i mean isnt it possible to smooth out the inflation so you dont see it using that high of smoothing?