Originally Posted by 3hree5ive0ero

In light of recent events, I volunteered to hold an independent and unbiased plenum spacer experiment on a VQ35DE RevUp engine. Tony of Motordyne has volunteered to provide us a plenum spacer just for this experiment. A few things had come up and we had to change locations but putting aside irrelevant details, this unbiased, independent experiment will take place at HPP Racing in Lewisville this Saturday, December 12th at 10 am.



Purpose:

• The main reason for this experiment is to determine whether or not the plenum spacer affects power output on the VQ350DE RevUp engine.
• Additionally, we will attempt to illustrate and explain any ECU shifting on the dyno, if at all.

Materials:

• A very lightly modified or stock 2006 350Z 6MT
• Cipher (for observing/recording parameters only)
• about 9 wideband runs on the dyno
• basic tools
• 93 octane gas
• MD 5/16" spacer

Procedure:

• We'll first reset the ECU before making any runs on the dyno.
• Then, we'll obtain 3 baseline runs. These 3 runs will also serve to get the ECU into performance mode, since we have a learning ECU that adjusts accordingly to our driving habits.
• The plenum spacer is to be installed, after which we will obtain 3 more dyno runs.
• Lastly, we will uninstall/remove the spacer that was installed in the previous step. We will do 3 more runs on the dyno with the now-back-to-stock plenum.

*Note that the car will remain strapped onto the dyno during our install/uninstall for continuity and to minimize minute differences/variability in dyno operation, strapping, rolling in, etc.



To be observed:

• AFR B1 and B2
• Accel ped pos 1&2
• Cal/LD value
• Coolant temp
• Oil temp
• Engine RPM
• Fuel Temp
• IGN timing
• Intake air temp
• Intake cam B1 and B2
• Exhaust cam B1 and B2
• MAF GM/S
• Throttle position 1&2

After the event, I will update this thread with the data/results.


Feel free to discuss what I have outlined above. If necessary, I will adjust our plan appropriately before the event actually takes place.

Originally Posted by 3hree5ive0ero

The test was successfully performed and I had a good time just talking about cars and being there in general. I have all the raw data and I will post up all info in this thread. I have yet to download the appropriate software for the Cipher's logs, so I need to figure that out. The dyno files are easy to do, since I have a viewer (WinPep7).

I was going to post these up this afternoon, but I had some issues with the crank position sensor (P0335) on my way back from the test and I had to limp home. I had to troubleshoot that once I got home and now I'm on my way out. Tomorrow, I will be attending a local dyno event all day, so it may not be until Sunday night or Monday until I can post these in easy-to-read/see formats (i.e., dyno graphs in .jpg format). I just wanted to update you guys, since I know waiting is never fun.

However, if you wish not to wait, you can download the actual raw data from both the Cipher and the dyno from this very post (attached below).

Some updates/changes in the procedure:

1. ECU reset performed via ground-disconnect method
2. 3 baselines obtained (no plenum mods)
3. ECU reset performed via ground-disconnect method
4. Motordyne's 5/16" spacer installed and made 3 more runs
5. ECU reset performed via ground-disconnect method
6. PowerLab's 3/8" spacer installed (replaces MD's 5/16" spacer) and made 3 more runs
7. ECU reset performed via ground-disconnect method
8. took off PL's 3/8" spacer and made 3 final runs with now-back-to-stock plenum

Yeah, I know that I said I preferred not to test PL's spacer, but it was readily available and the volunteer did not mind paying extra for 3 more runs. There was no ulterior motive so let's leave it at that and stick to the topic (unbiased, independent dyno experiment).

There are also some pics taken by the guy above this post (StuLax18). I guess he'll post them when he can.

If you want a specific dyno graph (i.e., run 2 and run 11 overlaid), then make your requests here and I will post up the graph as an attachment (in .jpg). Otherwise, I will only post up select graphs, but all will be posted regardless.

Lastly, you'll notice that I am missing the Cipher logs for the first run of 3/8" spacer testing. That's because the laptop crashed in middle of the 1st run and data was lost.
--------------------

Originally Posted by 3hree5ive0ero

I've attached 5 dyno graphs (multiple runs overlaid) below.

First attachment shows the 3 baseline runs.
Second attachment shows the 3 MD 5/16" spacer runs.
Third attachment shows the 3 PL 3/8" spacer runs.
Fourth attachment shows the 3 back-to-stock-plenum runs (no spacer).
Fifth attachment shows the overall best runs from each session.

All right, now I'm leaving for real. I'll check back on this thread later.

Originally Posted by Hydrazine

Here are some more dyno plots with additional smoothing to flatten out some of the large oscillations and make it easier to see what is going on.

This set of dyno plots is Stock Vs Stock.
It shows a clear gain of power in the second set even though nothing on the car is different from set one Vs set two. Depending on where it is measured it can be said there is about a 10-15 HP gain. (Phantom gains)





Best MD run Vs Best Stock Run
Within the margin of error, this is a perfect overlay of the plots. Is there really a 3HP gain in the last 500 RPM? No. Is there a loss of TQ with the spacer? No. This is normal dyno variation.
Blue = Stock
Red = Spacer




Best PL run Vs Best Stock Run
Within the margin of error this is a perfect overlay of the plots.
Blue = Stock
Red = Spacer




Margin of Error
The plots shown here are all stock runs. It gives a quick indication of the "set to set" margin of error. Note, nothing on the plenum has been changed in any of these runs. The plots should overlay eachother perfectly but they don't. Even though they are identical in plenum configuration, it can easily be shown to make a phantom 10+ HP gain from nothing.
Is there really a gain going from stock to stock? No. Is there a loss of TQ by going from stock to stock? No. This is normal dyno variation, it can be used to say or illustrate anything you want but the truth is, there is no change.
Every 350Z dyno owner is fully aware of this.




Just like the dyno plots shown in the first page of this thread, what all these plots here demonstrate is that simple dyno errors can be selectively used to show phantom gains if that is what you want it to show.

These plots also show that, within the margin of error, a spacer does absolutely nothing on the REVUP lower collector.

.

Originally Posted by WhosRich

In conclusion, Plenum spacers do not increase power in RevUp engines?

Originally Posted by Hydrazine

And that is where this dyno came from:



So its not that it doesn't make gains on the REVUP engine. Its that it doesn't make gains on the REVUP lower plenum. Its an important distinction.
I hope this isn't too confusing.


Happy New Year!!!
Tony