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Author Topic: Nefmoto Community Project: Large Turbo 1.8t ME7.5 A4 (8E0909518AK-0003)  (Read 12464 times)
Mike Tries
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« Reply #45 on: February 17, 2026, 11:25:09 PM »

OK, gang. The car is off-road is only now. Race car only mode. I have a dyno day scheduled next week. I'd like to develop a strategy to maximize the utility of the dyno. I'm not chasing numbers per se, but we do need hp to be as close to 285 as possible. The main objective is leaving with a car that behaves predictably and that can put down whatever power level we end up with safely, for extended periods of time, and in any weather condition or altitude. Frankly, if it gets terrible has mileage on the highway or behaves funny at very low throttle settings, I probably don't care too much... you know what I mean? We can compromise on streetability because it's not even possible anymore. (It doesn't mean we should throw that away, especially if this tune can be used by other people here.)

What would you guys recommend I spend the time doing? Should I attempt the pre-control linearization? Nyet, it doesn't appear as if you're a fan in a big turbo car. I worry about breaking rods during the higher WGDC runs.
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Mike Tries
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« Reply #46 on: February 27, 2026, 03:01:37 PM »

Alright, so I ran the car today. It did alright. There are so many internal limiters built into it that keep shutting things down before they get "fun". A great example is the anti-judder limit (KFDMDARO). It serves a purpose, but when you change things, it screws up your day.

KFDMDARO was already moved out of my way, so it wasn't an issue today. Just an example of the comfort and safety things that are in there that you have to know about before you can get rid of them.

We took the first couple of hours to get fuel and timing straightened out. Fuel was almost perfect, except for this goofy peak where it would jump from 11.5:1 (approximately... I'm just trying to get this written down) to 12.1:1, and then return. A killer? No, but it wasn't doing what I commanded right there.

Timing was being pulled--about 3 degrees, so I went into KZFW and KZFW2 and pulled three degrees out of both tables in the offending regions. I massaged that here and there until it wasn't pulling any timing. I'm running 93 octane, but at the track, I'll load in a few gallons of 100 octane just to keep it safe.

I am going to post an image of one of the dyno graphs. This one shows us 255 hp and 230-ish ft-lbs of torque. This is an improvement over where we were before. It's hard to tell how it's going to drive, so I'll try to bring it to the drag strip to get my butt in the seat once more before our first race, but it was OK. This particular graph is a bit goofy and has a massive oscillation in the AFR, but that's not how it's running now--we just pulled a graph off of the computer as we were finishing for the day and that was it.

I think that a lot of my issues with airflow might have to do with an apparently-damaged MAF housing. The straightener screen (the square-holed screen in the leading edge of the MAF) is a bit melted. That likely happened when something came loose and I didn't have a heat shield last summer. It is CERTAINLY making things challenging. Also, you need to have a straight section of pipe ahead of the MAF to allow the airflow to smooth before it hits the sensor. I had a filter parked on the end of it. That big oscillation might have been when we took the airflow straightener screen off to try running it. Don't.... do that.

The logs are messy. They were being generated and consumed rapidly today, so I didn't even bother renaming them. I just didn't have time when I was rapidly burning through time. We got boost to stabilize, but we kept running into an annoying limit up top that would bite me when I pushed too hard. Perhaps it was KFLDHBN? I bumped LDRXN while we were there, but I think I forgot to bump KFLDHBN.
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