I've been thinking about playing with my EU finally, and taking a serious approach to tweaking injector pulse width and possibly a little bit of timing adjustment.

Here is the latest data I have from cipher. I've noticed from using cipher several times now, that AFR @ WOT and timing @ WOT are very predictable... which is a good thing for self tuning

Please tell me where you think I should add fuel, and by how much. I don't think anywhere is too rich, so I'm not going to cut any fuel anywhere.

Also, where should timing be added (or subtracted) and why?

I've already formulated my own opinions about this, but I'm looking to get more opinions on the matter.

PLEASE NOTE THERE ARE 2 y-AXES ON EACH CHART! Left side corresponds to AFR. Right side corresponds to TIMING (BTDC) or Injector Pulse (ms)








Thanks
-Mike

 

This is your stock AFR numbers we are seeing now, right?

If so, looks like typical numbers from other logs I've seen where induction and exhaust mods are done on NA.

You pretty much just need to dial your AFR closer into 13.0. Your lean at the lower RPMs, and closer to the mark from 6k on up.

So if you add a little fuel through the rpm band and dial up 13.0:1 throughout, then you can go back in and get some timing back with a little advance.

As everyone else does, just get on the dyno and advance until you stop making power. There will be a "gap" between where you stop making power and before you start knocking. Being inside this range does you no good and will make your tune more vulnerable to slighter changes in external conditions (temp, humidity, etc.). So just advance until you stop making power, then back off one degree. Re-check AFR and adjust as needed in case the timing adjustments impacted your original AFR tuning.

I suspect I'm saying things you already know. But thought I'd chime in anyway.

 

Yep, what Smoky said

later
Aceman

 

you are seeing the current AFR numbers with the mods listed in my signature.

Sorta yes, sorta no. In any case I appreciate any input you have to offer.

So as far as timing goes, I guess for "street tuning" I shouldn't change anything but AFR. To change timing I'm going to need a dyno to chart the waters so to speak...

Important question: Since greddy EU has the capability to add fuel on each injector seperately, should I bother trying to even out the AFR for bank 1 and 2 ? As you see bank 2 is always a little bit leaner by about 0.25 points or so

 

Sounds like you could. But I know very little about the EU's capabilities.

I think the UTEC's Inj Puls maps just average the pulse across both banks? Not even sure how that works. Besides, I've been focusing on adjusting MAF v. You inj pulse guys are on your own.

Cool that you can isolate each injector. So you basically have a fuel map for each injector then?

 

I think so. It probably defaults to using the same value for all injectors, but I *think* you can change it on a per-cylinder basis.

Also, where is FIRST place to start increasing timing... low RPM, high RPM? Or just all across the board?

 

You probably only need to adjust at high rpms/higher MAF or PSI loads. So, in UTEC speak, probably only in the 70-100% load columns at higher rpms, at least at first.

 

Since both banks' injector pulses are the same, why is the AFR so consistently different? I wonder if the O2 sensors' or their circuit is off. Any way to swap the O2 sensors and see what happens? I suspect balancing the AFR on each bank can't hurt since a different AFR will make different power at the same RPMs. At the very least it should smooth out the power delivery, although you may not feel it.

 

My guess is due to the asymmetry of the location of the throttle body etc.

One bank is getting a little tiny bit more air. (Incidentally, it's the bank closer to the TB)

just another reason the vq35hr is going to kick ***

 

BUMP (why does this thread keep getting ignored)?

 

It wasn't ignored. I guess folks are not sure what else you want to know.

 

I believe the reason one side runs leaner than the other is due to the design of the stock fuel rails.

Thats why everyone says to place your O2 sensor on the driver side for a more acurate reading. I have a 2003 so i do not have the stock sensors like the newer 350z's.

Hope this helps

Later
Aceman

 

Sorry, I thought I was clear :

I could use some more specifics on what to do with timing map at WOT.

Should it be gradually increasing, rather than increasing > decreasing > increasing again?

ETC
It would be helpful if someone with a tuned N/A motor with a nice timing map could chime in as an example.

Thank you guys, I only hope more than 2 people respond to this thread

P.S. I think I have my greddy EU issues solved. Everything seems to work now, I created a "water temp map" to trick the computer into increasing water temperature reading by 20 degrees C. Previously, due to reasons unknown to me, the water temp was reading very low : causing the fans never to come on, and causing the ECU to throw a SES light for the thermostat.

By tricking it into reading higher, I think it is working okay now.



So, I'm ready to tune ASAP.