Hi All. Recently began modding my Z, getting some.. interesting data. Basically there's a 'corner' at around 6300rpm where power gain drops off, this correlates to a flat spot in
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02-21-2012, 06:41 PM | #1 (permalink) |
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2009 370Z - Questions about Data logs, confusing information.
Hi All.
Recently began modding my Z, getting some.. interesting data. Basically there's a 'corner' at around 6300rpm where power gain drops off, this correlates to a flat spot in the GM/S log from the Cipher. What is going on here? Is the ECU enforcing an artificial flow limit of some kind? The reason that I suspect that is the case because no other parameter clips at any point and friends with similar cars but with different parts (Aftermarket intakes for example) are getting the same clipping of GM/S. Any thoughts? Dyno and data below.. Thanks in advance! Code:
RPM| MAF-GM/S/|MAS B2|MAS B1 6063 258.4 4.09 4.01 6100 257.79 4.11 4.09 6138 257.18 4.04 4.15 6188 258.14 4.12 4.06 6213 262.09 4.05 4.2 6250 265.29 4.13 4.03 6288 268.79 4.07 4.17 6338 268.79 4.1 4.23 6350 268.79 4.18 4.1 6388 268.79 4.21 4.12 6425 268.79 4.1 4.23 6463 268.79 4.2 4.15 6500 268.79 4.2 4.15 6538 268.79 4.21 4.15 6550 268.79 4.09 4.23 6575 268.79 4.1 4.22 6613 268.79 4.17 4.22 6650 268.79 4.22 4.12 6688 268.79 4.17 4.22 6725 268.79 4.21 4.18 6738 268.79 4.23 4.19 6775 268.79 4.27 4.13 6813 268.79 4.2 4.26 6838 268.79 4.26 4.19 6875 268.79 4.18 4.28 6913 268.79 4.16 4.33 6950 268.79 4.23 4.33 6975 268.79 4.17 4.32 7013 268.79 4.25 4.33 7038 268.79 4.28 4.28 7075 268.79 4.22 4.37 7125 268.79 4.31 4.19 7150 268.79 4.32 4.2 7188 268.79 4.3 4.35 7225 268.79 4.31 4.29 7250 268.79 4.3 4.27 7275 268.79 4.28 4.25 7300 268.79 4.27 4.26 7325 268.79 4.28 4.26 7350 268.79 4.26 4.26 7375 268.79 4.25 4.24 7388 268.79 4.25 4.22 7413 268.79 4.24 4.2 7438 268.79 4.21 4.13 7450 268.27 4.16 4.08 Last edited by Sh0velMan; 02-22-2012 at 10:37 AM. |
02-21-2012, 09:25 PM | #2 (permalink) |
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I've noticed something similar in my datalogs. My MAF Gm/S usually maxes out to 268.79 at 6400rpm (and about 6200rpm in cooler weather).
This is with stock panel filters. What intake do you have?
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02-21-2012, 09:34 PM | #3 (permalink) |
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I have the drop ins.
My concern is that something in the ECU is holding the engine back. If that is the case, I don't see how an aftermarket intake would yield any gains. |
02-21-2012, 09:40 PM | #4 (permalink) |
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I think the issue is the intake capacity. When you look at overlaid dyno graphs of say, a Stillen G3 and the baseline with stock airbox, you notice the G3 graph continues on a more upward trajectory after 6400 rpm where the stock graph falls off more drastically.
Hopefully someone with more experience than me will chime in soon
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02-22-2012, 07:36 AM | #6 (permalink) |
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It's probably the VVEL tuning... currently a non-adjustable parameter.
If the power doesn't drop off, don't sweat it. If it does, you can probably fine tune the AFR targets to gain some back.
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02-22-2012, 08:49 AM | #7 (permalink) |
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That's the thing, power does drop off.
Once I have an aftermarket intake on the car we will dyno again and I can check the numbers for comparison. It may be of no consequence. If it IS the VVEL tuning, well, that sucks. haha. PS: I should say that the car will be getting an UpRev tune on it as well after we have added a few more parts, so it may be something we can add fuel and work around.. |
02-22-2012, 09:15 AM | #9 (permalink) | |
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Quote:
just a guess. Not pretending to know. |
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02-22-2012, 09:16 AM | #10 (permalink) |
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What's also telling is that you notice there's a hump at the end there, right before redline?
Check out the dyno I have posted in this thread, you can see the same hump.. DYNO - NISMO CBE and K&N Dropins |
02-22-2012, 09:19 AM | #11 (permalink) | |
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Quote:
Now what is funny is the hump just before redline. That, to me, looks like something they have put in there for high peak HP for magazines and bragging rights. If they were being competent engineers (assuming that the hump's peak is the theoretical maximum the VVEL system can achieve) they would have it continue to scale as normal and not flatten out at 6300RPM just to peak again 800RPM later. I think they saved their last hurrah for just before redline to boost their peak HP numbers. |
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02-23-2012, 11:48 AM | #14 (permalink) | |
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Quote:
I will update this thread once I have more data in that regard. |
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