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AEM INFINITY -6 Ignition timing and VVC... Andre?

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Hey guys 

Few months ago i replaced the AEM Series 2 with a AEM Infinity -6 ecu on my Evo 9. Fast forward few days after the installation I copied the  ignition table from series 2 and put it in the infinity ignition timing table (cell by cell) and the i pull 2-3 degrees just in case. I copied also the Mivec timing (VVC) and injector timing. Then i made some 25-26 psi pulls (98ron fuel). The result was massive knock. I retard the ignition 2 degrees and knock was less but it was still there. Just to be able to have 4-5° of ignition timing at 26psi,  i had to advance the intake cam to 26 degrees up to 8000rpm. If i tapper slowly to 0 degrees the intake cam with 4-5° of ignition timing again at 26psi the engine produce massive knock. ( i confirmed that by using plex knock monitor with headset and LinK knock detection)

My problem is. Why i can't have the ignition timing and VVC  that i had with series 2 and also with oem ecu? I can't even go close to the ignition timing of a tuned stock evo. In theory you slowly retard the intake cam as the rpm goes up. Correct?

 At 26psi the ignition table on series 2 and oem ecu was starting at 5 degrees at 5k rpm and 11 degrees at 8k rpm.

I checked multiple times the ignition timing with a timing light. (Locked at 10°) both ecus are solid 10 degrees from idle up to 6k rpm. (Free rev)

Any idea what is happening? :/

Thanks in advance

Alex

Did you set the base timing up properly? Ie make sure that 10degrees btdc crank is read as 10 degrees in the ECU?

There's was a recipient webinar on this, https://www.hpacademy.com/previous-webinars/058-setting-base-ignition-timing-aem-infinity/

Yes i did that multiple times as i mentioned. 10 degrees locked from ecu and with a timing light i confirmed back to back that 10 degrees in the software is 10 degrees on the crank pulley

Sorry, I missed that when I was reading your post. Is there any chance that the Series 2 wasn't set right?

Have you got any signal filtering on the series 2 that isn't active on the Infinity?

Could you post up your two maps, from the Series 2 and Infinity, and a data log from the Infinity to show what's going on?

I double checked the ignition timing with a timing light on both ecus on the same day. I free revved the engine up to 6k rpm on both ecus. It was a back to back test. All i had is a stable 10 degrees ignition timing. No signal filtering was used. The thing that is driving me crazy is the Vvc. It has to be at 25-26 degrees up to 8000rpm. I've never seen that on evo 9. Most tuners zero the VVC past 6500rpm. I can't do that without getting massive knock. And as a side note, when i tried to tapper slowly to zero the Vvc past 6500rpm the AFR goes rich if that tells you something.

Is there maybe a zero function zero the vvc? On the haltechs with toyota vvti, i found i had to zero its reference so that it knew where the cam's zero advance zone was. The Elite is nice because it automatically zeros at startup.

Maybe something to check. Could be that your vct is going further than it was set because its not zeroed.

I can see the cam position when the engine idles it's at zero degrees. If i add lets say 15 degrees on vvc map the engine idles poorly.

Hi alexui,

If you check your emails I've now had a chance to look over both files, so much for the holiday season as I've been non-stop in the shop! take a look at your VVC duty cycles, you may need to run the set-up wizard again for the VVC to re-zero it.

I think you need to edit your duty cycle scaling in the base duty table

Thank you very much for your time. The think that is actually matters is the Actual Intake cam position to follow the target Vvc. It does that pretty good as it has the feedback correcting it.

Sorry for the late reply. What you're explaining sounds quite strange. As others have already suggested, my first concern would be the base timing but it does sound like you've got that well and truly covered. I would suggest however if you can, checking with a timing light to ensure that it's tracking what you expect under high load - This really needs to be done with a helper on a dyno during a run and understandably some care is required.

You're right that 26 deg advance on the inlet cam isn't likely to be right at high rpm. You're most likely going to want the cam retarded back very close to zero by this point. As a sanity check, try a run with the VVC solenoid unplugged. This will have the cam in its most retarded position or zero degrees. Do a run like this and log the cam position reported by the ECU and see if you have the same issue with the engine taking timing.

Lastly you haven't mentioned how the engine torque is effected by the cam position? Is it responding in a normal manner? ie if you have 25-26 deg at high rpm, are you making less power than you were with a more sensible value? For the time it takes, I'd suggest confirming the mechanical cam timing is also correct on the engine.

thank you for your response Andre. What could cause a timing fluctuation only under load? and most important how do you fix something like that. ? As far as power/torque didnt strap it on a dyno yet. if i put more sensible numbers in vvc map i end up at 26 psi 7500rpm a total -3 ignition degrees ATDC to prevent knock. I triple checked the timing marks on cam gears and crank spoket.. from all those scenarios i would like to hear a possible solution

Any ideas?

I find this is not uncommon with the Nissan 360 optical pickup - They are more susceptible to triggering errors at high rpm and load than just high rpm alone. The EVO is susceptible to ignition noise if you're running the factory waste spark ignition system and non resistive plugs, although with the special long reach plugs the IX runs I'm imagining this isn't your issue.

Yes is the stock wasted spark ignition. How can filter the noise if it is noise though. Can i make it work with 12 tooth trigger plate with the VVC working? Below are the specs of the spark plugs I'm running.

http://www.ngk.com/product.aspx?zpid=9875

Those plugs are resistive so shouldn't cause an issue with interference. Before continuing I'd suggest getting the car on a dyno and getting some data on what's going on - ie how is cam timing affecting torque, and is the ignition advance following what the ECU is commanding at high rpm/load.

We usually reply within 12hrs (often sooner)

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