Slamrod

iTrader: (11)

Continuing here from my other thread, since this discussion no longer applies to that thread's topic
https://maxima.org/forums/5th-genera...-wideband.html

My setup: 2002 max, 14' HR motor, 4'' intake, 560cc injectors, 255lph fuel pump, cattman headers, 3'' exhaust. More or less what I have going on thats relevant.
I will be tuning with an APEXI NEO piggyback device, and using an Innovate LC-2 wideband to monitor AFRs. I will be using Nissan Data Scan II to try and log all of that.

So - day one with the setup. I set my IN/OUT to 1/17, LO/HI at 49%/50%. Putted over to the gas station just fine, however, when going into neutral as I slowed down, my motor stalled. I upped the idle to 850rpm to see if that would help. Did one run starting at around 1500rpm in 4th gear, took it until redline. HOLY FK does this thing scream at the higher rpms. Definitely feels a little more torque-y, but hard to tell for sure. The car stalled again when I let off at redline and went into neutral - this gave me a huge scare because when I bump started the car by going back into gear, it somehow triggered the car's MAF failsafe mode, where I wasnt able to rev above 2500rpm and it ran super choppy and rich. Really thought I blew my motor like an idiot, until I turned the car off and on again, which cleared it right up. Going over the results right now - using NDS2 for logging is new to me so Im still learning how to actually read what Im looking at. I monitored my AFRs while I was in the pull though; saw some jumps into the 15.xs but higher up it worked down to 13.x's and maybe even 12's - hard to keep track while doing 100mph lol.

Anyways, going to see what the log has to say, once I figure that out. Will update as I get further along. As always, if anyone has some useful pointers or advice, feel free to drop a line, Im always open to learn from others.

Slamrod

iTrader: (11)

Quick update:
It appears my gauge is not an effective tool to monitor AFRs. I noticed that there is a lot of latency with it, ie; it takes half a second or so to respond to changes. That - and my graph doesnt resemble what I thought I saw on the gauge during the pull. Heres my first pull's graph.



Not the best pic maybe, idk. I also dont know what parameters I should be monitoring - obviously RPM + AFR, but what else? I watched timing, just because, but other than that, whats important to watch here?
-Highest AFR according to the graph was around 4500RPM, at 14.1AFR.
-From 2000RPM to 3000RPM, average AFR is about 10.3.
-At 3000RPM, AFR jumps to around 11, and gradually rises 12.6 at around 3700 RPMs.
-AFR dips back down to a low around 10.2 by 4000RPM, where it gradually rises back to a peak of 14.1AFR at 4500RPM
-From 4500RPM to around 5500RPM, the AFR drops from its peak of 14.1 to around the mid 10's. It more or less stays in this general area until redline.

Sooooo.... It looks like I need to remove fuel pretty much everywhere, except for the mid 4k RPM range, where my AFRs peaked - here I will add some fuel. Again this is all very new to me. Do my conclusions make any sense based on this data? Looking for you vets to step in and steer ya boy slamrod in the right direction here. Thanks everyone!

EDIT: If anyone has suggestions on what to do for my stalling issue, that would be hugely appreciated! The RPMs fall very low when going back into neutral, and the gauge hunts around down there until it gets low enough to cause a stall. Blipping the gas seems to prevent this, but Id like to figure out why/how this is occurring, so I can fix it.

Child_uv_KoRn

iTrader: (7)

Usually too lean makes it go into limp mode. I assume you have 75mm TB? I would say you need to make sure it's clean, reset ECU (pedal dance) and relearn idle if it persists. I've never had that problem on any VQ UNLESS maf/TB was dirty/bad (I assume TB should be fine since pretty new). 850 idle should definitely help (and that's where it should be anyway for oil pressure). Also, check plugs. You could foul them fast running that pig rich. Clean em with a toothbrush or equivalent.

Is this just a stop gap till you get a reflash? She'll appreciate the higher timing and flow the HR heads can handle.

Virtually no one has ever tried to race me (headers and cattman 3"). Idk what the deal is. All of the pusstangs just hang back even if they're riding my *** trying to start ****. I downshift and go, then they just sulk LOL. I think the sound is offputing and makes em think it's actually highly modified.
Pretty much only ****us ST bois are willing to do anything lul

95naSTA

iTrader: (10)

For MAF and injector changes or tuning in general, it's best to get your LTFTs in check (as close to 100% as possible) first then dial in your WOT AFRs.

You can watch your AFRs all day in closed loop but unless you know what the ECU is trying to do with the fuel trims, you'll never get ahead of what it's changing. Open loop (WOT) AFRs are based off of closed loop corrections too, so LTFTs = horse, WOT AFRs = cart.

Slamrod

iTrader: (11)

Yup, 75mm tb. Still clean and all that. Ill try doing the reset procedure and see if that clears it up. Im able to prevent stalling by blipping the throttle but its really annoying to have to do every single time i coast to a stop in neutral. Plugs are original with the motor which has maybe 20k miles on it so im sure they are ok, but ill check anyways at some point.

Definitely a stop-gap until I reflash, since I already grabbed everything I needed to go the romraider route; its going to be a pretty long gap though. Right now I just want to tune best as possible using the NEO and see how that goes. I figure in a few months when the new mod smell wears off, itll give me something to do to squeeze some more power out. I cant get over how mean this car sounds now though! The growl is insane!

How does one get their Long Term Fuel Trims “in check”? Not being cheeky, just not understanding. Isnt that something the ECU gradually learns over time on its own from driving and monitoring the narrowband O2s? Not sure how to even incorporate LTFTs into all this - if you could give me an in-a-nutshell explanation on what I should be doing in that sector, that would be awesome. Thanks dude.

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Child_uv_KoRn

iTrader: (7)

You're correct, it learns and tries to correct AFR. Log the fuel trims and see what the ECU is doing when driving normally. You are close enough that it should be able to add plenty of fuel (max is 25%) and achieve proper values (so stoic when cruising). If normal driving is fine, then you don't have anything to worry about. I assume it can't be bad, b/c you haven't said anything about it. I had no issue whatsoever.

95naSTA

iTrader: (10)

There are base fuel maps, short term trims or corrections (STFTs) and long term corrections (LTFTs). Your ECU starts off with the base maps and the narrow band O2 input will generate STFTs that will either be above 100% if it's running lean (adding fuel) or below 100% if it's rich (removing fuel). This feedback only happens when the car is up to operating temp and in closed loop. When the coolant temps are low and at WOT, the car is in open loop and doesn't look at the narrow band O2 for corrections. The STFTs will eventually change the LTFTs to establish a new effective closed loop fuel map that's the original map scaled by LTFT corrections.

If you're driving around and you're logging 120% LTFTs at x MAF signal, your ecu is adding 20% more fuel at that MAF signal to get to where it wants to be. So, you would increase the MAF signal at that point by 20% to make the ecu think that that much more air is coming in and it needs that much more fuel.

To get started, I would just get a general average of what the LTFTs are and scale the whole MAF curve based off that number. Drive around for a while so the STFTs change the LTFTs. From there you need to log various static points by driving at the same speed/rpm/throttle input (including at idle) to get an average for the same LTFTs at x MAF signals. If you can MAF scale off TPS or RPM, you'll want to scale the same signal under those different inputs accordingly. Then scale the MAF signal points as required, drive around again so the STFTs change the LTFTs and repeat the log/scale process again. It'll take more than a few tries to get it dialed in. You can reset the ECU after every re-scale to reset the fuel trims quicker also. On my piggy-backed 4th gen ecu, the fuel trims relearned pretty quick.

Yes, the ecu will learn and compensate in closed loop but it's only really designed to do this +/-10%. The car will run best the closer you get the LTFTs to 100%.

After your fuel trims are settled in, then you would log WOT AFRs and recale the MAF as required. This way the fuel trims won't change and run the risk of impacting your WOT AFRs.

MAF scaling only works so well because you can be under various load conditions for the same MAF signal but it'll get you close enough.

Slamrod

iTrader: (11)

Funny that you say that. Did a few more pulls, 2k-redline in 4th gear. I seem to be flattening my AFR - still rich (low 11s) until 4kish, then it jumps up (now in the mid 13s where i want it), then starts going rich again in the 11s. Before, it would be in the low 10s, up to the 15s in the 4k range, then back to the 10s. In any case it seems im making progress in the WOT category.

However, the car is very erratic while cruising/light throttle. AFR is jumpy, car doesnt run smoothly, basically it just does not want to be there. Itll be near stoich and then the AFR just starts climbing to where I have to give it more throttle or else it gets way too high and starts bucking. I have no problem stating that I think thats because i am tuning incorrectly with the NEO. Maybe yall could shed some light on this?

So on the NEO there is 16x2 RPM points, one LO, one HI. Currently i have both maps sharing the same points (1000, 2000, 2400, 2800, 3200, 3600, 4000, 4200, 4400, 4600, 4800, 5000, 5400, 5800, 6200, 6500). I am also adding/removing fuel equally across both maps. I suspect this last sentence is *WRONG*

My LO/HI setting is at 49%/50. Does this mean at anything under 49% throttle, it will use the LO map, and above 50% use the HI map? Under that logic, it makes sense why my WOT output seems to be improving (since im tuning at WOT), and my partial throttle output is so messy. The fuel corrections are different between partial/WOT, thus I should be tuning separately for each map. Is this train of thought correct? Or am I so lost I dont even know how Im lost?

Going from there - The car seemed to cruise just fine before I started mucking with the NEO. Should I negate all my LO fuel corrections back to 0? Next, i cant see being at partial throttle anywhere above 3k rpm. Is the idle-3k rpm range the only spot I should focus on the LO map?

Really, my confusion here is stemming from my ignorance on how to use the NEO correctly. Im going to go ahead and wait for you fine folks to help shed some light here before I do any more pulls.

Im also still fuzzy on the LTFT topic; this is “A/F ALPHA b1” and “A/F ALPHA b2” in NDS2? Or is it “A/F ALPHA b1 s” and A/F ALPHA b2 s”? What do the numerics mean? Am I trying to get it to 100? I suppose I can probably dig up this info myself lol. Really my main issue right now though is using my NEO correctly - Ive searched endlessly and im just not finding the specific information i need to continue, at least not in a way im understanding.

Thanks guys! Having a blast doing this even though Im still not quite sure what im doing. Going from just wrenching to tuning feels like Ive finally entered the big leagues lol

95naSTA

iTrader: (10)

So yeah the NEO looks like it has two sets of correction maps based off that threshold Lo/Hi setting. That will let you scale open and closed loop signals that way. But, everything I said about getting the closed loop fuel trims right first still applies. I would probably keep the low map populated up to 4500/5k. If the car runs and drives with the low maps all zero'd out, I would start like that then do what I said above about getting an average LTFT, scale then go from there.

A/F ALPHA b1” and “A/F ALPHA b2

These are the long or short term fuel trims for each bank. You should have 2 sets of these, one for short and one for long. The shot term ones (STFTs) will bounce around a lot even at constant speed or conditions but the LTFTs won't change as quickly. You want to be as close to 100% for LTFTs as possible.

Slamrod

iTrader: (11)

Im still not understanding what you mean. Like im getting the concept of LTFT, but i dont know what you mean by “getting them right”. If the ECU learns LTFTs on its own, how do i affect that? Like Im not understanding what I am supposed to do in order to get them at 100. Is there like a setting im supposed to modify? also not understanding what you mean by “scale” in regards to LTFT. Sorry if im circling around the same point over and over but its not clicking for me just yet.

How about the NEO stuff? Are my presumptions correct, ie; do i understand how the LO/HI functions? Or am i off? Again, im assuming that LO is only active under 49% for me, and HI above 50%. I assume this, because i have been doing my corrections for WOT pulls, which have been getting better AFRs, while my cruising went from decent to really choppy. In a nutshell, I *SHOULD NOT* have the same corrections at each RPM point between LO and HI, correct? As in, i should only be touching the HI map when adjusting my WOT AFRs, and LO map when adjusting AFRs while cruising? Probably a really simple point but I need to be sure im correct before moving forward.

95naSTA

iTrader: (10)

The NEO scales the MAF signal in order to correct the fueling then therefore changing the fuel trims. If you change the NEO settings (scale the MAF) on the low settings like you have been for the high settings, only basing it off AFR, you may never get the corrections right. Because, like you said, the ecu is making it's own corrections.

This means if your long term fuel trims are making corrections over 10%, like LTFTs at 80% 85% 115% 120% etc. your ecu is straining to get the fuel right. How you avoid this, and get them right, is by logging and changing the NEO low set points so that the ecu doesn't have to compensate as much.

Yes. Correct.

Slamrod

iTrader: (11)

Ok! I think im starting to follow you here. So step one moving forward, I should reset LO map corrections to 0. From there, I should monitor what the LTFTs want to do, and then correct the LO map where needed.

As a hypothetical, say the LTFT wants to add 10% fuel - am I adding 10% on the LO map to “beat the ECU to the punch”, so to speak, so It doesnt need to make the adjustment itself?? Or am I removing 10% to counteract what the ECU is trying to do, to maintain an equilibrium of my choosing (ie; 13.5 AFR)? Basically, do I mirror the LTFT with corrections to prevent those trims from even needing to happen? Or do the opposite of what the LTFT is trying to do? Logically, the first scenario seems correct to me, but I just want to be certain.

I understand this is probably braindead simple stuff, and I have no shame admitting I just dont get it, yet. Just trying to hammer this out, piece by piece, that way I can 100% be sure Im tuning safely. Also ive found threads like this where people who are knowledgable are willing to spell everything out for dunces like me are super helpful for those who use the search engine. Anyways, once again, THANKS!

Edit: I think i got it. Reset ecu, see what the LTFTs are trying to do, adjust corrections until the LTFTs are close to neutral as possible, then i should be able to make adjustments more accurately. Whats the fastest way to get LTFTs stored into memory? Just lots of driving?

95naSTA

iTrader: (10)

Tuning fuel is not hard but if you've never done it, it'll take more than a few mins to wrap your head around it. Once you start doing it and it makes sense, it'll stick. I've tuned EFI 6 different ways on 4 different platforms but it's all been the same concept from the start.

So yes, if you're seeing 110% LTFTs (it adding 10% more fuel), you will want to add 10% so the ecu doesn't have to. The ecu will always try and get around 14.7 AFR partial throttle, what most cars try to run outside of any power enrichment mode, rare lean-burn cycles or high content ethanol mixes. Generally for WOT on a n/a engine 12.5 AFR is safe and 13.0 is pushing it.

Yeah, the quickest way to get the LTFTs stored or set for anything outside of idle is by driving. Idle of course is just letting the engine run to let it figure out it's fuel trims.

Basically there's a Load vs. RPM fuel table in the ecu and each time the engine is in one of the cells in the table it looks at the NBO2 voltage to see if there's too much or too little fuel. It's only a switch: high/low, too much/too little. It has to cycle through the different cells to populate the fuel trims or corrections. STFTs are the short term memory that bounces all over and LTFTs are the average the long term corrections.

Slamrod

iTrader: (11)

Alrighty. Pretty straight forward stuff. Im still unclear on how to develop my LTFTs though. After doing an ECU + idle reset, I took her out and drove around for a little while.

I understand what the Y-axis for the trims are (+/- fuel), but whats the x-axis that it gets compared to? Rpm? Afr? Like how do i interpret the data so I can correct accordingly? So far my LTFTs are showing +4%, but only at idle. STFTs on the other hand are also +4% at idle but spiking all over the place, down -20 to -25% while cruising in lots of spots but more mild in others. Almost entirely in the negatives though. Im assuming only idle got saved to LTFT because thats the only area that had consistency, but I dont know how I can tune idle off of a NEO, especially when the ECU seems to be keeping it around 14.7 well enough.

Anyways, I guess im supposed to just pot around for a while, if I cant tune accurately until I have LTFTs? How do I tell when my LTFTs are developed? Is this something I do over an afternoon? A week? A month?

Also, side note - is there a way to change the Y-axis scale inside of NDS2? My AFRs are on a scale of 0-140, which is retarded considering they only can range from like 7 to 23 or something like that. Theyre being squished into a tiny part of the graph which makes it practically impossible to read.

Slamrod

iTrader: (11)

Here are two graphs from the latest logs I took of me driving around aimlessly.

Log 1 - Much longer session



You can see that while cruising, the LTFT is pulling -17% fuel at its lowest point. Seems like a lot to me, shouldnt my LTFTs be much more narrow? Isnt that part of the 4" intake +560cc injector gimmick? Idk honestly, you guys tell me. I also dont know what to make of the square waves that the LTFTs are displaying on the graph. Am I supposed to take the average value of that wave? How do I decide how much correction to do if the wave is fluctuating a lot? Or, does the square wave mean that the ECU still has not learned a stable LTFT yet - thus I should keep driving till the square wave flattens out? Basically wtf do I make of these graphs lol.
Edit: It just occurred to me that I was often letting off the gas, or giving it a little more gas, at various points while trying to cruise at a set speed - my AFR would behave erratically and the car would drive a little choppy - giving it a little gas or letting off the gas before continuing smoothed it out. Maybe this is the explanation behind the square wave Im seeing?

Log 2 - Much shorter session but easier on the eyes



More or less the same as the first log, just a smaller data set. Ignore the part where I stall, LOL - still having issues with returning to idle after going into neutral, very rare she stalls but the rpms are still bouncing around below idle before they settle where as before the idle reset it would stall practically every time.

Anyways - what can I do better for collecting data? Should I drive at a set rpm for a while (ie; 1500, 2k, 2.5k, 3k) while at partial throttle, so I can see what the LTFTs are doing at those rpms, and therefore be able to adjust corrections at those specific RPM points? So far I just drove around normally. Another thing - Do I clear/reset my ECU data once I see clearly what my LTFTs are, and then correct from a 'blank slate'? Or do I leave those LTFTs active on the ECU and tune around them?

Child_uv_KoRn

iTrader: (7)

Hmmm, I don't recall what mine looked like. I can tell you that I just view the data in real time. What were the AFRs while cruising? Something seems ****y, regardless. There's no reason to have any issues other than slightly lean. Are you sure that maf isn't ****? Crappy maf would have a very hard time reading such low airflow rates.

Cruising looks pretty okay to me, though. The variation is only 11%. It's correcting it and it's well within the margins...I wouldn't worry about it if AFRs are ok. If not, then there has to be a maf issue. There's no reason for normal driving to vary wildly. Who knows what the actual result of that fuel trim fluctuation even is. It could be reading it funny or really doing a kind of averaging method...**** if I know.

If you can't fix the stalling (without a reflash), then you could just suck in unmetered air. Put a breather filter on the driver's VC port and drill out the pass's PCV valve. It'll suck in a little air and keep RPM from falling. You can relearn/adjust idle if it goes too high. I run stock DEs like that (with catch can).

Slamrod

iTrader: (11)

Well according to the graphs, if its pulling fuel, that means it wants it to be even leaner - which makes no sense considering I should be already running lean with the 4” intake. At least thats how I thought it would go.

AFR was all over the map. Constantly fluctuating between rich in the 12s and then lean in the 15s. I would have included it on the graph, but for some reason NDS2 isnt capping the values that can be presented for AFR; full lean on my gauge shows 22.1AFR or something like that where as NDS2 allows that value to go all the way up to 140. This makes no sense, since any data outside the 7-22 range is unusable - but since NDS2 displays AFR as 1-140, all the data points are being squished into a sliver of the available graph space, making the AFR a scraggly unreadable line rather than letting it spread out nicely across the space available so I can actually read it. Anyways - AFRs were extremely inconsistent. They definitely averaged in the ballpark of 14.7, but they would fluctuate constantly even when I didnt change speed/rpms at all.

Maybe i do have a failing MAF? I did actually have some hesitation and bucking issues over the summer that went away after i cleaned the MAF... I always thought it was fine since i never got stuck in limp mode. Dead MAF is easy, but how do i determine if its simply ‘not quite dead’? Is there a dataset in NDS2 I can look at? Whats the best option for MAFs these days anyways?

EDIT: Heres the 2nd graph with AFR added.


Note how the scale on the Y-axis goes up to 140. I cant find any option/setting to stop it from doing that dumb crap, so unfortunately you cant really see the true scale of the AFR fluctuations since NDS2 insists on squeezing it on the very bottom. According to the graph, it seems I am indeed running a little lean - I monitor my AFR gauge while driving but it has a lot of latency and doesnt really seem to be accurate. The sections where I am cruising, AFR fluctuates from very high 13s, to very low 15s. It is operating almost entirely in the 14.x range. I think the fluctuations are just the STFTs going haywire because the ECU doesnt know wtf Ive done to it lol. I checked the longer graph also - pretty much the same pattern.

95naSTA

iTrader: (10)

Ignore decel fuel trims and zero throttle.

Child_uv_KoRn

iTrader: (7)

Oops, I had RWD on the brain describing PCV crap. Same thing just not in those positions.

Slamrod

iTrader: (11)

Dude im sorry, you straight up spoon fed me and I didnt even realize. Didnt really know what you were talking about when I originally read that post and I guess I just forgot about it. Looking back its pretty much clear as it can get, so thank you for that. Ill update later today with how all this goes.

Slamrod

iTrader: (11)

Really narrowed down the LTFTs today. Spent a few hours holding different RPM points in different gears and watching what the trims were doing, and adjusting accordingly. Should have them nailed down completely by tomorrow, or at least enough to my satisfaction, and finally get to WOT tuning. Im still having issues with going back to idle, although I think I know a solution. Currently my lowest RPM point is at 850, which is where my idle is. My idle itself is fine, but returning to idle, especially when dropping from a higher RPM, usually caused the car to almost stall before recovering a stable idle. I suspect this is because the RPMs are going past my lowest corrected RPM point, where nothing is tuned, and the ECU doesnt know what to do down there, causing it to stumble for a moment. Im going to sacrifice another RPM point and put it around 600ish RPM, to see if it works as a 'safety net' when the gauge briefly dips below idle. I figure if i temporarily set my idle to 600rpm and let it sit for a couple of mins, it should give me a LTFT for that point and let me know what to correct for down there.

AFRs seem stable while cruising (average is close to 14.7), ride has gotten much smoother than initially, definitely more torque - im concerned about my timing curve though. I honestly have absolutely no idea what is considered normal or even safe. My initial WOT runs that i logged (with no real tuning done yet) seemed to line up with charts ive seen on google images (20s and low 30s BTDC), so I dont have any concern there. But my cruising/partial throttle ignition timing is in the mid to upper 40s BTDC. Is that sketchy? This is taking place at very low throttle imput, just highway cruising, 2400-2800RPM. I am pulling 15%-20% fuel on average across my LO map, which in turn would advance timing. Just want to make sure I am not inadvertently doing anything dangerous that will pop my motor. Engine load seems to be directly contrasting with timing, with timing being at its highest point when load is relatively low, and sharply dropping when load spikes. If anyone can shed some light on what I should be watching in regards to timing, things to be careful of, etc etc, it would be greatly appreciated.

Child_uv_KoRn

iTrader: (7)

Timing is completely normal. It's adding a little as you said, but stock ECU is already detuned enough, so it's fine (although some 1st gens do ping stock). You're not going to hurt the engine, regardless. You'll hear it pinging if knock sensor doesn't catch it, which I wouldn't expect to happen at all except in summer heat. Also, I heard HR heads can handle more timing.
If you go on a long highway drive, do a fill up before and after to calculate the MPGees. I bet it's pretty good.

Slamrod

iTrader: (11)

Ok, cool. I was worried that timing would be an issue since I cant modify it directly, but its good to hear that I dont need to worry. I did more snooping around the internet, and while every motor is different, I read from a few different sources that modern engines regularly can go into the 50’s with ignition timing BTDC when cruising under low load/light throttle to improve MPGs. Ironically, as you implied, I should be getting pretty good gas mileage, as least when my fuel trims are nullified. Itll be hilarious to me if my mileage is better than stock - probably would be if i stuck strictly to cruising but i think WOT is going to chug gasoline like crazy even after I tune for it. This whole thing really has come along - I think I should have it finalized today. Going to finally be doing some WOT runs that I can get solid data from!

On a side note, Im starting to appreciate the shortcomings of going the piggyback route, even though im not even done using it yet. Theres a lot of quirkiness and rough edges the car has now, that I just dont think a piggyback has the complexity to tune and smooth out. For example, having 16x2 maps - should be excellent for WOT tuning since those conditions dont change much. But theres so much variation in partial throttle conditions that giving it just one map for all those various conditions just isnt enough. It of course runs and drives well enough, but its kinda feels like Im using the “free trial version” of tuning - theres too many variables my NEO isnt built to handle and you can definitely tell while driving. In any case, its a massive amount of motivation to start learning how to reflash using RomRaider/NisProg/etc so I can nail this sucker down to perfection. I think now that Im getting the very basic fundamentals down from this piggyback crash course, that getting into reflashing should be straight forward - last summer or so I shelved it because it was too much to take in at once.

With all that said, wish me luck. Ill be posting back later this afternoon with the results from today’s tweaking.

Slamrod

iTrader: (11)

Alrighty guys. I think I have more or less run my course with this whole debacle. The car has its full bolt-on setup and tune, all by yours truly. Definitely can clean it up a little more - couple of minor peaks and dips in my AFR but overall shes pretty stable. Im going to need to redo all my RPM points again to place more in the 4k-5k range, since the combination of the power curve being there, having VIAS open around 4.4k, and being somewhat close to where i land with upshifts, means there is a lot of things going on that require much more defined tuning points. Im also still having the idle issue. I tried placing an RPM point below where my idle is, but that didnt help. For some reason it hits idle, stays there for a few second, and then starts struggling to maintain idle before a few before fixing itself. Cant figure out why, but obviously it has to do with the oversized 4” intake.

The car is faster, no doubts about it. Not really noticeable driving around normally (why would it be?) but at full throttle the difference is huge. My overall impression though? I really hate to say it, but Im just not feeling fulfilled by this one. Sure, we all like a fast car - but not having the “OEM” drivability anymore has already gotten old. Nothing major, just little things - falling flat (sometimes) when taking off from a stop, idle issues (sometimes), the motor stumbling when feathering the throttle (sometimes)... no amount of time (or power) will make me not notice those issues.

I knew coming in that piggybacks have their limits, and now I understand fully what exactly those limits amount to. It absolutely has been a blast to work with, and invaluable towards my effort to learn more about automotives, but at the end of the day, I feel like Im still at square one. Its like trying to paint a masterpiece but you only have the 6 colors to work with. Sure, you can do a whole ton, and improvise here and there, and you might have surprisingly respectable results - but its never going to look as good as the one done by a full palette. What makes tuning off a piggyback so appealing is also precisely the same thing that makes it unappealing - its simplicity. Its easy to pick up and learn and quick to give decent results. Its also just as quick to give you a dead end brick wall in functionality.

With all that said and done, I think this is pretty much the end of the road for me and this thread, in terms of updating it with stuff. I can tweak things all day and tinker, but at the end of the day, my NEO aint going to satisfy me - no sense in wasting additional time and effort on something that has no future for me. More than happy to share what I learned and discuss anything people have questions about though!

At some point in the near future Ill be reviving my RomRaider thread and continuing my tuning efforts there. Should at the very least make for some much more interesting discussions! Thanks again to everyone who lended me a helping hand with all my questions and concerns.

95naSTA

iTrader: (10)

I'm pretty sure I ran a 3.5" intake on a 4th gen ecu with a VAFCII, basically the same thing. That was with a Q45 MAF too. I was already running E-manage Ultimate when I switched to a 4" intake. E-manage is a true piggy back though. VAFCs NEOs etc. are really just MAF translators.

I know it's a different scenario because you're drive by wire but IMO you should be able to get the idle to work with your NEO. It's not like your ECU has multiple load cells around idle. The resolution you're working with should be fine.