Apexi' NEO tuning/general tuning advice

[mattmk3]

Originally Posted by cre

I don't have time to go over this tonight, but here's a tip. Smell the exhaust. Unburnt fuel causes a lean reading on a wideband. You are fighting with this more than someone with experience but no more than any other novice, especially when they've made too many changes at the same time. Set the fuel pressure to stock. Set the NEO to zero across the board. Look to see how far rich or low you are across the board and make a mainscale adjustment to account for that. Then trim each section as needed on an individual basis. The ECU doesn't learn how the engine is running from one single session and I believe it continually adjusts to changes as well. After the first couple drives it should be pretty well set though. Resetting the ECU when the car is cold or hot isn't going to do much it's looking at averages from multiple samples.

DON'T PANIC A lean idle isn't an engine killer unless other things are wrong (no EGR to cool things down, heavily advance ignition, etc.).

Is the stock O2 sensor still installed? Or is the AEM providing the ECU with a narrowband signal? If the AEM is providing the signal make sure it's properly scaled and the wiring is rock solid... Doesn't take much to throw the signal off enough to cause the ECU to think the AFR is WAY off and perpetually over correct.

Just noticed an error I made, I said RICH when it should have said lean frying things but i think you picked up on that.

I've been driving it around, it feels awesome, and I've gotten into boost and it's actually a nice range of mostly around 11-11.5, dips to 10.5 at some points but in full boost, never hits 12. So it's actually boosting quite nicely. I think it may still be learning idle and cruise though because it has dropped from 17.9/off the chart to 17 and idle sometimes goes down to 15 but then climbs back up. Maybe it's trying. I think I'm just over thinking it and just being paranoid.

Utilizing stock o2. EGR IS removed. Is that a possible problem for EGT's? I've been meaning to get an egt gauge. Timing is stock spec for turbo engine.

Side note: Since it's running well under boost, i decided to crank the boost up to 17 and see how it goes. A/f's are still solid, pulls like a maniac. Gota be sitting up towards 400whp (basing off of my last dyno results and what i did to get there).

The question: Twice and only twice, when I hit it hard, preloading and then dropping into the boost, It puffed a decent cloud of greyish smoke. Not white, and not the black shit i used to spit out. Is this an indication of anything bad or just a hard working engine? Only a puff, didn't do it the whole pull.

I'm going to go through and make sure all my intercooler pipes are nice and tight and make sure everything else is good to go for 17psi. My only other issue is a oil burning issue from what I've narrowed down to be the valve stem seals.

Thanks!

[cre]

17+ AFR is leaner than you want at idle. It may creep there on occasion on a sound setup but shouldn't spend most of its time there.

Removing EGR on vehicles made after the 70's is just ignorant or motivated by vanity. It doesn't effect performance at all while at WOT (as it's off then) and it helps cool the engine after a hard run. As for the latter... MOST people couldn't give a shit what it LOOKS like under the hood. It kills me how people try every single trick they can to increase performance and at the same time nickle and dime themselves out of power based on the opinions of some guy with a mullet, '65 Mustang and 12 pack of Budweiser in his gut. Don't worry though, it's not going to kill your engine with it removed.

Are you having any issues with AFM related error codes? Are your AFR trends significantly different after cold starts vs warm? What do you mean by "preloading"? Brake boosting? The smoke is probably either running rich or oil... hard to say without seeing it myself.

[mattmk3]

Originally Posted by cre

17+ AFR is leaner than you want at idle. It may creep there on occasion on a sound setup but shouldn't spend most of its time there.

Removing EGR on vehicles made after the 70's is just ignorant or motivated by vanity. It doesn't effect performance at all while at WOT (as it's off then) and it helps cool the engine after a hard run. As for the latter... MOST people couldn't give a shit what it LOOKS like under the hood. It kills me how people try every single trick they can to increase performance and at the same time nickle and dime themselves out of power based on the opinions of some guy with a mullet, '65 Mustang and 12 pack of Budweiser in his gut. Don't worry though, it's not going to kill your engine with it removed.

Are you having any issues with AFM related error codes? Are your AFR trends significantly different after cold starts vs warm? What do you mean by "preloading"? Brake boosting? The smoke is probably either running rich or oil... hard to say without seeing it myself.

No codes or anything. This is what I mean by what the hell is my cars deal with me doing this mod. How do I go about richening up idle? it's still 17 at idle and 15-16 cruise, really light cruising 17.

Not quite brake boosting but putting a nice load on the engine then hammering on it. Just building up the boost as apposed to just waiting for the turbo, it builds more boost, quicker, so it seems that's when the most stress is on things. New note on this, I get this strange, very fast sounding, not quite a rattle, more of a grind, but not quite a grind. haha impossible to explain so I have my gopro with a remote mic and i'm going to place it in a couple spots in the engine bay and see what that noise is. It seems it happens over 17psi boost; so when i put some load then hammer on it, it spikes for a second but keeps up there and I hear it. It's only happened a couple times but if i were to take a stab at what the noise may be, I picture the compressor wheel of the turbo grinding into the housing... But the turbo is recently rebuilt and upgraded...

Cold and hot afr's actually aren't too different. Been driving it since I posted this thread, so a couple days now. Still pulls hard, feels great throughout the powerband, my turbo spools quicker a lower rpm. I just DON'T like the lean idle. I did some research, 16afr cruise isn't even bad so I'm only worried about idle at this moment.

[mattmk3]

So today randomly after pricing out some tires, it was warm, sat for about 25 mins, then i went out and shortly after, it started to have a shity idle. It has gone more lean, it's off the chart at idle now(18afr+) and it sounds like it's cammed. shaking and shit. NOW what... I didn't change anything.

[mattmk3]

Is it possible it's my fuel filter? I show pressure up to and beyond 40psi, but i'm not sure if that's a guarantee the fuel filter isn't holding it back. I'm trying to figure out why it wants to stay lean. What else could it be? I have a walbro 255 to put in but like i said, I can get probably 55psi maybe 60 and that's it. Only cranked it up to see how the 12v mod effected it.

[cre]

If your AEM has a narrowband output Try disconnecting the stock sensor and run the AEM narrowband output to the ECU. Wideband AFR's aren't "off the scale" until they hit about 22... A limitation of your wideband perhaps?

No, it's not your fuel filter or pump... You'd have MUCH bigger problems under a load than when you're at idle.

Part throttle boosting often involves the throttle still being open at a low enough angle that the ECU is still in closed loop operation and adjusting the fueling trying for 14.7:1. Check that this isn't the case. If it is then yeah, the cloud is probably extra fuel from the sudden surge when you finally stomp on it and the ECU goes into open loop.

You've tuned your fuel pressure while at idle with the vacuum disconnected? What pressure are you running presently?

I'd start looking for that noise in hardcore mode... Noise isn't good. Especially if you were running lean while booting and didn't catch it (been there, done that, replaced pistons).

What are all of the settings you're running now?

[mattmk3]

Relatively new AEM wideband, sensor mounted in the correct spot/position. Just for the record.


Yes, vacuum disconnected, running 40psi. Any less and it wouldn't say below 18afr('off aem gauge scale'). BUT now it is staying above 18 at idle, no matter the fuel pressure.

As for the noise, I didn't hear it other than those first 2 times, 1 was with the boost controller setup shity, so it spiked, but did not go lean. (looked at wideband gauge when i heard the noise). Other time also not lean, but with the boost controler setup properly, at 17psi, but with a preload on the turbo then stomped on it, it may have boost spiked but it didn't go lean so i'm not worried about the pistons at this point, although i do want to do a compression test just to rule any of that out.


Settings as in for what?
-Greddy profec b 2 is setup to boost to and hold 17psi (no spiking or creeping or dropoff after an hour or so of tuning it)
-NEO is setup for 0+/- across the board but also turned compensation off, so no fuel compensation but naturally it's still rich in boost with the 550's + lex afm.
-Fuel pressure 40psi (no vacuum, at idle)(also has 12v direct relay mod)
-ECU was reset when i initially installed the lex afm(about 6days ago, i haven't driven it the past 3 days)