Nietzsche

iTrader: (7)

So I went out last night to do some base 3rd gear pulls and datalog the results with my new system. I have a weird issue that I don't recall ever seeing(or maybe just not noticing). At 4k the motor bogs and just sits there for a second. Every time with out fail. Looking at the logs later it actually would hit 4k then back down to 3.9k then go foward from there. Ignition was not being pulled and I can't figure this out for the life of me. Also I would like some advice on where to proceded on how to tune. I ran really rich up top, 5500-6500, other than that I was pretty good I thought. Also how much further can I advance my timing for realistic for power gains. Also the timing would swing up and down so I don't know if the cars being conservaticve or if it has to do with any variable parts, ie..vias, cvtc, etc..

I can't upload files so if you'ld like the excels just pm.

Thanks for the help as always.

NmexMAX

iTrader: (22)

How do you plan on advancing timing more? What does 'really rich up top' mean? What were the actual numbers? Post a timing log (w/re: to RPM)

Nietzsche

iTrader: (7)

Emailed you the files. Running low 12 high 11 in the uppers.

95BLKMAX

iTrader: (10)

If the 6th gen ECU is anything like the stock 5.5 gen ECU, then up at the higher RPMs its not just the "running rich" part of the equation, but the ECU is also progressively closing the e-Thorttle Body as it gets closer to redline. That would cause the a/f ratio to apear going richer and richer towards redline.

If Im wrong here some1 please correct me, but ^^ is AFAIK

Nietzsche

iTrader: (7)

I think it has been proven that that does not happen. I performed various tests and never saw a closing effect on the throttle body in upper rpm's before. I don't remember the thread but someone else logged various sensors and never found it to close.

95BLKMAX

iTrader: (10)

ok thanks for correcting me on it.

NmexMAX

iTrader: (22)

You're rich up top, not a surprise. Z33's also see this (stock) and so do our A33B's. You have the same ECU as the Z33, so that theory makes sense. Take some fuel out, gain power.

Just looked at your logs, and yup, pretty rich up top. Also, the timing you logged is for the intake cam. And yes, it is variable so it will do some funky stuff. When graphed WOT, there is a patternt hough. Read this for more info http://forums.maxima.org/showthread.php?t=262261

Log IGN timing, that will give you more information and also would be nice to compare a 6th gen.

Nietzsche

iTrader: (7)

I don't remember seeing that as an option but I'll take another look. Any thoughts on the 4k lag in the motor? I've heard that the timing can make the biggest difference on VQ motors. If you advance timing does it richen or lean out the mixture?

NmexMAX

iTrader: (22)

Log IGN TIMING (BTDC).

All you did was advance the base timing, which is only affected under 2300 RPM.

That lag is strange. It be nice to see timing logs.

nismology

iTrader: (8)

I'd also like to see intake cam advance, IPW, and throttle position logs...

NmexMAX

iTrader: (22)

Stock A34 vs TS modified A33B

nismology

iTrader: (8)

I was thinking more along of the lines of his particular curve to see if it has anything to do with the bog @ 4000 RPM.

Nietzsche

iTrader: (7)

I checked for that and didn't see any correlation. My log looks identical to the one NmexMAX posted except for the lag at 4k where I plateau instead of peak. This is my first excel chart so bare with me.

NmexMAX

iTrader: (22)

Stop being teh It states stock A34.. Where else would I have gotten an A34 curve

With that said, that log comparison I posted is his particular data set.

All FWD VQ's have the small dip @ that RPM. Check eng92's thread where 6spd_Hayes posted his.

Puppetmaster

iTrader: (48)

I think 6spd_Hayes thread with a similar chart is around here somewhere as well.

As already posted, the dip in intake cam angle at around 3800 rpms is normal for those of us with the dual stage IM it seems.

To the OP, what are you using to datalog? Your UTEC? Or something else?

NmexMAX

iTrader: (22)

He's using Cipher. . . .

nismology

iTrader: (8)

x's 1,000,000,000

NmexMAX

iTrader: (22)

Just replying to your question

Nietzsche

iTrader: (7)

So intake cam dip aside, any thoughts as to the motor bog at 4k? I'll take some more runs tonight.

nismology

iTrader: (8)

IPW = injector pulse width...

Nietzsche

iTrader: (7)

I didn't log IPW but the TPS is pinned at 4.18 the whole time. When I go out tonight I'll make sure to get AFR, IGN, IPW, TPS, IAT. Anything else I should look at?

nismology

iTrader: (8)

You sure it was throttle position you were logging and not accelerator position? Just wondering...
I would say MAF voltage too...

Nietzsche

iTrader: (7)

Positive it was the TPS, accelerator would be pointless in my opinion. I'll make sure to get the MAF as well.

95BLKMAX

iTrader: (10)

This should be interesting info indeed! :fiddles fingers as he waits infront of the computer for results:

Nietzsche

iTrader: (7)

Here's some of tonights runs. You can see the lag in the numbers as well as the graph. I don't lose any speed with the bog which is weird and all the parameters stay steady. The files are in my post HERE

NmexMAX

iTrader: (22)

Strange results. I graphed speed vs time, and no lag, just in the RPM scale. Everything else looks normal. Do you see/feel any difference at that RPM?

He is logging TPS #1. Typically APPS 1/2 give s lightly higher V than TPS1/2. But in this case, it's an invalid point.

Puppetmaster

iTrader: (48)

According to Hayes' logs, the TPS also has a 1/4 sec DBW lag from the APPS. Not to take this any farther OT, but I'm just sayin.

Nietzsche

iTrader: (7)

That doesn't have any effect on the readings though.

You can definitely feel it hesitate but the speed keeps climbing in a linear fashion. After much debate I'm thinking it has a direct correlation to the power valve opening and changing the air flow geometry. I don't see why this would cause the motor to hesitate but another member pointed out the MAF voltage was being disrupted leading him to believe it was something on the intake that was changing.

NmexMAX

iTrader: (22)

No matter what the time lag, there is always a difference in V, APPS always gives the slightly higher value, no matter how long you hold it. Also, 6spd_Hayes may need to have the TBW hesitation TSB performed. Because mine does not do that IByouhaveTS

Yes, something affecting intake charge is changing. And it does make sense. Just wondering if it has always felt like that or if its just recently happening. I also felt that small lag. (when the VIAS switches)

Nietzsche

iTrader: (7)

I have never noticed it before but I wasn't paying attention. Now that I realize it does it I always notice. It's just like when you notice a dead pixel for the first time on your flat panel and then you always see it. I guess since it doesn't effect forward momentum it's not that big of a deal. The ECU did get pulled so I assume that the fuel tables where cleared. I'll give it another week of logging before I attempt any tuning.