Mechanical Rev Limiter VE - Explained

Hello,

I'm having a "problem" with my 1.7-liter Opel engine (engine code 17D).
Normally, the car would typically run at speeds of 150-160 km/h according to the speedometer, depending on the route.
While more power would be available with a steeper incline, at 160 (presumably referring to a power setting or speed), my foot lifts off the pedal because I don't want to overstress the old tractor.
The speedometer should register approximately 140 km/h. Since the speedometer is always inaccurate anyway, that seems about right.
Last weekend, I replaced the timing belt and sealed the water pump, adjusted the fuel pressure to 1.05-1.1 bar, and then adjusted the fuel injection quantity to minimize smoke. I should mention that I'm running rapeseed oil (rapeseed methyl ester) in a two-tank system.
Now, regarding my "problem":
Yesterday, I was in a bit of a hurry on the highway, so I was driving fast, even though there was a slight downhill slope. I quickly glanced at the map, and then my eyes drifted to the speedometer...
180, and increasing.
I then shifted into a higher gear and managed to maintain a speed of 160 km/h while only partially pressing the accelerator.
Even on inclines, where the car usually drops to 120 km/h, it reached 150 km/h.
I've had the chance to test this setup several times, driving the A3 between Nuremberg and Deggendorf, both ways. The whole thing is running on PÖL (presumably a specific tuning or fuel type), but it's still lacking about 10% in "performance."

Since I only had to make a minimal adjustment to the idle speed, which is normally affected by the fuel-oil mixture, I'm ruling out the possibility that the throttle lever is misaligned. I also made a mark before disassembling it.
I also wouldn't consider limiting the gas flow, as I would have to adjust it too much, and then I wouldn't be able to achieve any acceleration at all.

I have to go on sick leave now, and I'm worried that the engine might explode during the maximum RPM test, or that if I ever lend the car out, someone might accidentally rev the engine too high.

How do I limit the maximum RPM, or is there a speed limiter in the ESP system that I may have inadvertently disabled while sealing something?

Regards,

Hopel.

Hi there,

My 1Y (1.9L naturally aspirated engine) in my Audi 80 also produced 174 horsepower at the end, instead of the advertised value.
According to the GPS, the speed was 164 km/h. The flow rate and control parameters were also adjusted.

The valve lift determines the valve spring package in the ESP.
The maximum travel of the gas lifter, should come apart there.
but even with over 5000 calls per minute, there's nothing.

Best regards, Michael.

Hello,

I haven't made any changes to the throttle linkage. The throttle lever should be in the correct position as described.
I'll measure the wheel circumference tomorrow and then calculate the speed based on the gear ratio.

Regards,

Hopel.

Hello,

Today, I measured and calculated the dimensions of a wheel.

At 160 km/h, the engine is running at 4300 RPM.
At 180 km/h, the engine is running at 4840 RPM.

So, overdoing it won't do anything.

The only question that remains is why the oven suddenly seems so eager to rotate.
Is that only due to the early start of feeding and the higher feed intake?
Based on my feeling, I would say that before the ZR (likely referring to a timing belt or similar component) change, the ignition timing was slightly more advanced. However, I didn't measure it; I just adjusted it based on what I heard.

Regards,

Hopel.

I would just say that it's probably set up correctly now. ^^

Hello,

hopel wrote:

Only one question remains: why is the oven suddenly so eager to spin? Is that only due to the early FB and the higher FÖM?

You've had the same experience as many other people. Our van ran 137 km/h on the speedometer with diesel, and 143 km/h with Pöl. The Toledo, with its original 75 horsepower (AAZ) engine, ran 170 km/h with diesel and 185 km/h with Pöl. The engine's rev limit remains where it should be, but these cars simply pull better at the top end. Your pump setting was probably suboptimal before, and I suspect that the car now emits some smoke when running at full throttle with diesel.

Best regards, Uli.

Hello,

The car never runs at its maximum speed using diesel; it always runs on gasoline.
The car is mainly used for long distances, and if I'm driving short distances during the week, like to work, I don't bother with switching modes. I think it's okay to use "Dino" fuel about once every three months, considering I drive around 4000 km per month.
"Therefore, I've never tested it. However, I would say that it has a bit more "oomph" with diesel. I definitely notice the 10% difference, and with 57 horsepower, every little bit of power makes a big difference, especially when cornering."
The valve clearance is already quite tight, it's supposed to be 0.9mm originally. I hope the head gasket will hold up in the long run.

Regards,

Hopel.

Hi,

hopel wrote:

I would say that the Diesel engine has a bit more "oomph." I definitely notice the 10% difference, and with 57 horsepower, every little bit helps, especially when taking turns...

What about 10%? Pöl is not biodiesel. With Pöl, it's only 5% at most, theoretically. In practice, I've noticed more power in all areas of operation with Pöl, even my girlfriend notices the difference. If she has to use regular diesel for some reason, I can hear her complaining afterwards: "When will we have Pöl again? The car doesn't have enough power and it's smoking."

Quote:

The font size is already quite small, the original specification was 0.9mm.

I hope the print head seal will last in the long run. }

"The head gasket might be okay, but the pistons will shrink if the engine doesn't have piston cooling. They'll get hotter than normal, expand more than usual (as much as they can, since they're constrained within the cylinder), and then shrink back down. Over tens of thousands of kilometers, they'll slowly become thinner. You'll eventually notice this in the oil consumption if that's the case."
I experienced that with my "1er Sauggolf" because I was running it near the soot limit, or slightly beyond it.

Best regards, Uli.

Hello,

I'm expecting around 10% in terms of P-value. If it's only theoretically 5%, that's fine too.
"At the very least, I need 6.0 liters of diesel or 6.5 liters of heating oil per 100 kilometers with the same driving style. So, a 10% difference wouldn't be that surprising."
For me, the performance is better with diesel. At least the low-end torque. So, the power you need for city driving in stop-and-go traffic.
I can't really detect any significant lag. But I usually just quickly jump onto Dino, then onto the highway with Pöl, and then I drive 800 km straight through.
I use Dino for the rest of the short trips because otherwise, the Dino tank would get too dirty and would never be completely empty. Every 3 months, I also want to put in some fresh fuel.
It's probably a matter of modifications, or rather, how much optimization has been done in the direction of using a wood-burning stove. I haven't changed anything on the engine itself, except for the fuel burner and the fuel oil meter.
The nozzles are still the original ones with an unknown number of operating hours, as they came from a vehicle that was used for scrapping.

The mention of piston shrinkage makes me think, because KBK definitely didn't have that engine (MKB 17D). And the 16DA that was in it before certainly didn't either.
The 16DA has been removed due to compressor surge.
The problem appeared relatively suddenly and was accompanied by a sharp increase in oil consumption. It went from almost nothing to about 2 liters per 1000 kilometers.
I attributed it to age, or I thought it might be due to a broken oil scraper/piston ring or something similar. The machine's mileage was also unknown.
Piston shrinkage introduces a new aspect.
I also upgraded the engine to a level that was still somewhat acceptable in terms of fuel consumption (FÖM).

Will the sudden realization of worn pistons occur abruptly, or is it preceded by symptoms like difficulty starting/increased oil consumption (due to loss of compression) over a period of several thousand kilometers?
Tell me more...

Regards,

Hopel.