Observations/Questions from new owner

[flipski]

Hello everybody!

I just purchased a 350Z G4+ for my car. It is a 2003 with Plenum spacer, High Flow Cats and Nvidia Gemini exhaust. I've installed the G4+ and I am trying to start to tune this baby and I am questioning if I am doing it right, which I am probably not. But here are some observations/questions that I've made.

1. TPS (sub)

Is it me or the sub channel of the TPS is reversed ? This is coming from a automatic calibration. Under the OEM Ecu, both channels are 0V closed, 5V open.

2. On a former log using the OEM ecu, nissan is holding the idle rpm using 15% TP throttle. The basemap of the 350z shows a TP position of 2.5% only. This makes the engine iddling lean as the oem injector don't put barely any fuel and I need to really increase the amount of fuel. What I do see is that the OEM is using retard timing to keep the idle speed but the G4+ only uses the TB.

3. Talking about timing, I had to advance my trigger offset by 6deg in order to match the 10deg timing mark on my crank pulley. Is that normal ? It seems to me that either the 6deg of retarded timing could be a safeguard to "hurry up" tuners.

4. dwell time. When measuring the timing, I actually used a spark lead and use that lead as inductive source. This way , I was able to measure the timing "including" the dwell time of the coils. Now because I saw a 3ms dwell time, I dig into the ignition dwell table and noticed the dwell time differs from changes in RPM. Isn't dwell time just the time it takes for the ignitor to spark ? why would rpm changes that ? help me understand please.

5. I have installed a Innovate LC2 coupled to a LSU4.9 wideband on the bank 2 only. My AFR reading are very inconsistant at TP% below 10%. Is that normal for this sensor. Does it requires a minimum exhaust flow to become accurate ?

6. Torque management. The 350Z is based on the G4+ extreme. Can I later work this feature to work on a manual or is this only for automatic where the Trans TCM do the request. I am thinking about doing some kind of rev-matching later on. Yeah! I know , I am far away from it now.

EDIT: 7. I have a twin VVT engine. Both Basemaps included shows Inlet and Exhaust activated. Should I keep it this way ? or deactivate all exhaust VVT signals ?

 

Thank you.

I really like the software, It is easy to understand for a very beginner like me. Also thank you for the wiring and setup help. This enabled me to install it all by myself ( yes, I am proud of it)

Francois

[Leiden]

Keep in mind that the basemap supplied with the ecu is really just there to get the vehicle started, set the trigger offsets, inputs, outputs and confirm things are working before getting it tuned.

[cj]

1 - yep thats relatively normal. It means interference affects the signals in opposite ways and allows better ECU level fault detection

2 - the lean or rich condition at any RPM (inc idle) is because of your fuel table, not (directly) your tps angle. Idle control is a mix of TPS angle and ignition timing. You can have lots of 1 and hardly any of the other, or somewhere in the middle with an average amount of both. There is a whole lot of logic to why you might do 1 or the other, but typically OEM's use lots of throttle angle and low ignition angle to help warm things up quicker as low ignition angle causes more heat. More timing gives you better throttle response (to a point). Typically on a modern japanese engine you would set ignition to between 10-20 at idle then find what TPS angle gives you the idle rpm you want. As well as the main ignition map there is ignition idle control which works on ia separate MAP + it reacts to idle target mismatches, and only kicks in under defnined thresholds - this is probbaly similar to what you are talking about.

3 - timing as far as the calibtration process goes is just telling the ECU what angle on the crank sensor matches what postition in engine rotation - eg its looking for a specific tooth or pattern on the crank wheel which it calls "0". The calibtraion process tells the ECU where its arbitrary "0" mark is compared to TDC/10 deg/whatever your base timing is. If your mark is at 10 deg, make sure you set the calibtration timing at 10 deg, then change the offset number (and press enter) until your timing light puts 10 deg on the block marking. 

4- what you did for the timing check light trigger is correct. Dwell is the time it takes to "charge up" the coil pack prior to firing it. In the scheme of things this happens a long time before firing - eg dwell might be 3ms (3000us), but the time for coil discharge migtht be 50us. the dwell table tells the ECU how far ahead of time to start charging each coil pack. That 50-120 ish us offset in the calibtration window is where you account for the firing time. dwell changes mostly with available voltage, but can be shortened at high RPM mostly to prevent running into the tail end of the previous firing event. With individual coil packs this is bascially not an issue though (something like 15-20krpm before you overlap firing events at 2ms? its simple enough to calculate)

5 - you probably have an inconsistent idle position or fuel table. The sensor may have a fixed groudn offset depending on your wiring, but any fluctuations are almost certainly a truthful representation of current fuelling performance.

6 - i'm not really sure what you want to achieve here. throttle blip control is possible but a bit crude. It sounds like you're trying to integrate with some other systems but without info on why its hard to give you a good answer

7 - VVT control if tuned right can get you a lot more mid range torque. People do disable it if they dont have the ability to tune it and still get good results, but you are leaving something on the table by doing this.

[flipski]

5 hours ago, cj said:

Thanks a lot for you input.

1 Thanks. it seems weird at first.

2 So the basemap is just a very crude map. Right now, there are set to 2.5% TPS and 40 ign angle. I will work on reproducing OEM idle mapping and see where temps go.

3 - Again, the basemap was off by 6 degrees. I guess I am good with such large variance between basemap and my engine. 

4- Thanks.

5 - That is probably due to the low throttle angle. The fuel resolution is probably too wide for such low volume of air. Raising the TP% might help stabilize it.

6 - I think I was looking at the wrong settings. I might have to look into the "motorsport" area.

7 - What I meant is to disable any input/output related to the exhaust VVT, while keeping the intake VVT active. Will test to see if this makes a difference.

 

6 hours ago, Leiden said:

Keep in mind that the basemap supplied with the ecu is really just there to get the vehicle started, set the trigger offsets, inputs, outputs and confirm things are working before getting it tuned.

Yes, the basemap enabled me to fire it up. I was just afraid since the changes I made were so far off this basemap that I was doing something too extreme or did something wrong with the install. Thank you.