NefMoto

Hey guys, just did my first log and the numbers are way off, are there some variables I missed? it's showing WHP and WTQ a lot higher than it should be. Same with actual BHP and Torque and it looks a bit all over the place on the boost.

.csv and image of log below. I've only just started using the logger so I assume it's my error somewhere.

Ok, I just changed expected drivetrain loss from 25% to 8% and it looks a bit more accurate. Am I really making 255 BHP and 305 ft/lbs of Torque? I expected to see around 230 BHP and 250-260 ft/lbs as I don't have an oversized tip and figured I'd have some fine tuning to do.

Here's the timing preset, not quite sure what to make of it.

Ignore crank HP, it is a worthless metric. wheel HP is all that matters. Also make sure your rpm/mph is correct and all of the other inputs (drag, etc) they are unique to each model car.

In general you don't care about HP when tuning btw, unless you are comparing back to back runs and want to know which is making more power. Even then small external changes (such as IAT) can have a huge affect on measured HP.

Absolute numbers are pretty much meaningless, and even relative comparisons can be misleading. The primary purpose of the logger is not to measure HP.

Thanks again for the helpful replies, always feel welcome on this forum.

I'm starting to understand the logs a little. I'm assuming that there is no knock as the graph shows them all moving together and no huge spikes.

I'm looking at Engine load and Maf values now. I've got specified load at 220% max which is the value in my LDRXN. Engine load caps at 135% request and requested and specified follow each other perfectly but cap at around 168% also my maf readings seem a little low with a peak of 125g/s

Just put the correct weight in and it's showing more accurate now at 200 bhp. I know this isn't important right now but seems a bit more reasonable. I just need to work out why Engine load never gets as high as requested and specified/corrected. Unless it's not supposed to on a flat road haha.

I think I need to go back to the wiki, but I'm working under the assumption that I'm being limited by KFLDHBN as my requested load doesn't reach my LDRXN specified load but is in line with corrected.

Bit of an update for you guys, I noticed BTS was kicking in at at 5250 RPM and it matched up with my IDC's spiking to 95% and beyond. I've tapered the boost off some more at 5-6.5k to try and work this out.

Just a quick question, my boost spikes at like 18 psi at 3k but instantly drops around 5 psi by 3.5k and then goes up again a few psi and does it in a few places, does this sound like it's pulling boost or is it an old actuator symptom?

Westgate duty cycle is low even up to 18 psi but it spikes at 95% right at the drop.

That is the PID trying to get boost to track requested.

Something is definitely wrong with load. Your MAF is either way underscaled or there is some other issue, leading to an abnormally low load and corresponding too much timing.

Could it be the fuelling presets in ECUxPlot? I've edited the maf to 68mm, but I don't know if the offset in g/s is right, it's set to 6.0 as a default
Also what would be considered a CF when it comes to knock and timing pull? would a single volt/degree count and need to be corrected, or is there a threshold that I should be keeping under?

I'll be logging again today after some adjustments, I'm going to start a bit more conservative and build up slowly.

The car feels really good and is pulling better. So either my maf presets are wrong or I've asked for too much boost too early and it's pulling timing to try and keep things in check. I've kept my changes to the minimum. raised LDRXN and 80-100% in KFMIRL, richer LAMFA and slightly lowered the values in KFMIOP on the last load lines.

No , the presets are for hp and tq and etc calculation, the maf values come straight from the ecu.. Knock voltages are useless, it doesnt correspond when you are getting knock or not.

Ok. So logging knock is useless? How would I know if I'm getting knock then?

From what I saw in the log it's pulling ignition timing from around 2k all the way to redline, starting at around 3-5 degrees and ramping up to like 12-15 degrees. I'm guessing that this is why I'm not seeing much load as it is being pulled due to timing.

I've lowered the boost quite a bit and tried to log again today but I'm having some problems with the logger. I've been starting the logger and then getting into third at around 1.5k rpm and holding a nice clean pull all the way to red-line, but today's logs aren't showing any data unless I turn off the filter. Not sure why it didn't get a FATS because it was fine yesterday.

But yeah, something is off, if the calculation is anything to go by 125g/s = around 150 BHP, and it's definitely faster than that.

You have this completely backwards. It is possible you are requesting too much timing because the ECU thinks the load is lower than it is.


You need to figure out why ECUxPlot isn't seeing the run as complete.


That is probably the worst way to estimate if your MAF readings are accurate.

No. The fueling presets are for estimating AFR for the AFR simulator and for measuring (real) flow for the compressor map graph if you have an underscaled MAF. Both are documented.

I'll know more when I get the log working. What would cause the car to see less load? I read your reply about incorrect maf scaling but it's a stock maf and I haven't changed any of the maf scaling maps.

I understand though. Timing increases as load decreases. So the car is seeing less load and adding too much timing. Could this be down to too high of an initial load request at low rpm in kfmirl and ldrxn?

I've been thinking about this load problem. It was my understanding that load was determined by mass air flow and relative manifold pressure. Does that mean I could be looking at a MAF problem, not seeing all the air that's coming in?

Yep, that is the most likely problem but you'd see fueling problems too (you should be running very lean if unmetered air is getting in)

The car is going really well though so it's quite surprising. My target AFR's looked fine on the log but injector duty cycle was spiking as bts was kicking in, I just put this down to maxing out the injectors by asking for too much boost.

Do you have a stock MAF sensor in the stock intake?

Stock MAF in stock housing. Silicone TIP and pod filter. I cleaned my MAF about 2 months ago. No fault codes and no issues, still spins the wheels into second if you hit it hard enough.

I guess just chalk up the very low load to exhaust restrictions and TIP

You'll probably want to pull timing accordingly, or maybe you have a bad batch of gas

It's got a 3" decat downpipe and back box delete. So I've opened it up a bit. It's leaking on a join near the back but I doubt this would adversely effect a turbo engine. 

Maybe the maf is degraded but not quite out of spec, either way it was perfect in stock form. I'll give it another clean and log maf values in vcds after I put the stock map back on. I'll keep you updated.

PS: I'll check the tip out as well, just in case it isn't seated on the turbo properly. I know this can be a good source for unmetered air, thanks.

Your MAF reads 125g/s with 1800mBar at peak RPM, if you haven't touched any of the MAF calibration values, you should know it's FUCKED. Stock MAF readings on an AUM are around 130-135g/s. You should be able to see this by looking at short term fuel trims on the stock file, and LTFTs should give it away too. That's what happens when you're a n00B and know nothing and think you can just go and mess with stuff and MAKE POWAR.

Not sure how that comment is supposed to be helpful. Like you said yourself I haven't touched the maf. And I've picked up that the readings are low. The changes I've made will make more power. I'm adding boost and targeting richer afrs. So I'm not sure how I'm a noob who is messing with the wrong files because I'm new to logging.

If my maf is bad or I'm sucking in unmetered air then I'll work from there. But my lack of experience at tuning has nothing to do with a maf issue.

Again, the question is why the problem isn't visible in the trims.

I've just checked the TIP and it's nice and tight on the turbo inlet, so it's not an intake leak after the maf. Not getting any codes on VCDS but I know these things can go bad before they go out of spec. I haven't had a chance to take it out and log again because I'm at home full time with my daughter during the week. I'll keep you updated.

@Nyet, I didn't think I'd logged LTFT's and STFT's on my run, are you saying that they look ok from what you can see?

You don't need to log them, you can just read them in VCDS with the ignition on.

http://nefariousmotorsports.com/forum/index.php?topic=837.msg7863#msg7863
http://nefariousmotorsports.com/forum/index.php?topic=837.msg8043#msg8043

LTFT
Group 032: 001F (rkat_w), 0021 (fra_w), 0020 (rkat2_w), 0022 (fra2_w)

STFT
Group 033: 001C (fr_2), 0025 (usvk ), 001D (fr2_w), 0026 (usvk2 )

Jeeeeeez, someone shoot me now

There is a reason I've posted in n00b questions. This is my first time logging a car. Obviously there is an issue with load which I'm addressing now. I'm not sure why your being so negative.

I've done a lot of work to the car and I'm not seeing any fault codes. It starts first time and idles fine and pulls very well. I wouldn't even know there was a problem if I hadn't logged the car in the first place. But your making out like it's because I'm new to tuning and don't know what I'm doing?

I'm working under the assumption that the maf is degraded, I've taken it out for a clean but it might just be on it's way out. I did pick up that my maf readings were low. All I know is take maf and divide by 0.8, I have since been informed by Nyet that this is a bad way to calculate it, but it would at least give me a rough estimate, and I expected to see 200 or so g/s. I realise that 145 g/s is lower than what stock would be putting out. I didn't think I had a problem because the car is going at least as well as it used to and I can hear more boost. I now realise that it will be making more boost with less timing and is probably around the same as it was before mapping. I'm also going back to stock until I get this maf reading sorted. Lesson learned. Getting there with the logs.

Don't get discouraged, this should be easy to diagnose. Start with posting LTFTs and try different MAF sensors if you can.

I wont. I know I'll get there, I'd just rather be back at stock if I'm running lean. I've given the MAF a good clean, I don't mind getting a new one if needed I just know there are expensive as it's not something you cheap out on :)

When I got the car it had been neglected and the coolant system was bodged, I've had the head skimmed and put it all back together with new timing kit and hoses, upgraded aluminium coolant flanges, the works.

If trims are in order and the MAF reading is low, then whoever put your engine together fucked up the valve timing.
Or your dump valve is fucked.

What prj said. Also log ps_w and compare with actual boost.

Or the MAF is so old and fcuked that no amount of cleaning will ever revive it. My advice? Buy a brand new OEM one from VW, NOT from Bosch or any aftermarket "OEM parts" suppliers (motor factors and so on), that have been selling an awful lot of chinese junk "remanufactured" MAFs that just are wrong.

Sorry I haven't been active in a while guys. Been busy with real world stuff. I unplugged my MAF the other day and it runs basically the same if not a bit smoother. Been getting some hesitation and surging here and there before I unplugged it so I'm pretty certain it's dying. Bit of a strange one though, I've driven the car a few times since I unplugged it and it still hasn't triggered the EML yet. I thought it should trigger as soon as I unplug it? Would explain why it hasn't complained about the MAF though if the EML for it doesn't trigger.

PS: I put the engine back together and the timing is all correct. I replaced the belt so I had the bottom timing cover off and made sure the witness marks were all lined up.
I'll plug it in to see if has developed any error codes. Everything else is fine. no intake vac leaks, most hoses replaced with silicone and a healthy new 710p dv from a trusted VAG supplier.

Edit: EML for MAF finally triggered. Just took a few runs out after unplugging it for it to come on. It came on when I went out earlier. I'm going to try and get a log later to see my fuel trims. I have free vcds lite so it only measures up to block 25. Does anyone know if the blue FTDI cable works with vcds?