Wired 24/7

iTrader: (2)

So, if I gas up with 100 octane, should the EU advance timing ok?

Hydrazine

iTrader: (53)

It depends on how much margin was left in the ECU timing advance capability when you originally did the tune.

If it was totally maxed out at the time of tune, then there is nothing left to advance. Maybe the Cipher timing advance can help here?

Ziggyrama

iTrader: (15)

I see what you're saying. I should have clarified my statement better. When I say more timing, I meant more timing detonation free If you advance too far, detonate and force the ECU to whack timing as reactionary measure, then yes, reducing timing will give you more power because the reduction you made will probably be less than what the ECU will remove due to knock. Also, detonation is not optimal combustion so the engine efficiency will drop when it's knocking.

I think it all plays into how the ECU handles knock events. I've seen ECUs that have rought and fine correction measures and the total timing formula is dependant on both. Usually, the fine correction is just an additive to the total timing profile. So, the fine correction is an instantaneous way of pulling back timing at that time, without effecting the rest of the map just to handle a brief, minor knock that does not warrant major timing changes across the map. Small pings here and there are not catastrophic so this fine correction is just for that.

Rough correction I've seen is usually when serious detonation is encountered. I've seen it done through a multiplier which is used to calculate total timing. When you knock badly, the ECU whacks the multiplier down and now all of the timing in the map has been reduced to take preventive measures so that the engine does not go boom. It's a drastic, preventative measure and it will cost you power.

The Nissan ECU may do something similar to a rough correction and whack timing across the board if it sees detonation. It may explain why you loose noticable power when you advance timing and detonate briefly. I'm just speculating here.

Sounds like Cipher does timing advance differently than EU. I'm willing to bet Cipher writes to a RAM address in the ECU which tells it to advance the timing in this area of the map. The ECU will do what it's programming dictates and will use the value as instructed. That's really how good, real-time tuning tools usually work. You're not fighting ECU to get the job done.
EU is probably a band-aid measure where it does some kind of a "trick" by altering or injecting the signal sent from the ECU to advance the timing after the ECU already did the timing calculations. The timing may get advanced for a brief period but what probably happens is the ECU recognizes the fact that it is running too much timing it and it pull it back. That is probably a safety measure in the factory programming. Again, this is all speculation on my part. But I think it's safe to say that they do the advance differently. One seems to work, the other does not

Good info guys. Thanks for sharing all that.

cvt

iTrader: (1)

i really need to get a tune...my car's been running like poop since my headers...

Jeff92se

iTrader: (4)

The Cipher is only able to perform Nissan Consult type changes. So it can change the base timing +/- 2 deg approx. They can't access individual ign maps and change them (yet)

Wired 24/7

iTrader: (2)

Yeah unless UpRev releases some really awesome software .....

which would probably be like $1000 ...

Jeff92se

iTrader: (4)

Wired. You ever talk to that other guy and discuss the timing advance thing?

laswyguy

iTrader: (1)

execellent update!!

Axelerate

iTrader: (19)

I have had my Utec tunned for about a year and I just got it dynoed again last week and everything was just like it was the day it was tunned. It even put down the same numbers, almost to the decimal.

Only problem is I just added a Mrev2, and didnt see anything on the dyno. The car is running a tad leaner with the Mrev, so it is doing it's job.

The dyno operator said the car is getting heat soaked, and it was pretty hot and humid, so I am hoping my higher numbers will show up when the temps come down. It still can be leaned out some more since it's right around 12.5-12.8 at WOT. The TQ looks good and everything is very smooth, it has a little hicup above 6,500 but it seems the ECU is pulling timing because of the heat soak.

Oh, and headers did not make my car any louder, just slightly deeper. You have a hard time noticing the sound difference unless you spent 2 days installing them with me.

Wired 24/7

iTrader: (2)

Interesting - do you have any dynos with AFR you can scan?

Axelerate

iTrader: (19)

I have the dynos, but they dont have AFR on them.

tylerxfire

iTrader: (15)

im still not sure on this, hesitating to pull the trigger, i have a non-revup and i have intake exhaust, 5/16 spacer, want to get the mrev2 because of the gains they claim on their site, but now im hearing its not worth it for the non-revup and is a nonrev-up with a little machining, bla bla bla. . so whats the status, do it or not. I will be getting a utec tune after. or should i go with somethin like underdrive pulleys instead. i already have clutch and lightweight flywheel . basically debating on mrev2 and underdrive pulleys

turbodreams350z

would the 5/16 plenum spacer make my engine light go on ???

Hydrazine

iTrader: (53)

No.