Weird dyno output: APR Stage 1

[wuta3]

Hello all,

I did some dyno runs yesterday which produced the outputs below. There was an odd dip in power/torque at around 5000rpm, which then recovered to where you'd expect the curve to end up.
Regardless of any other variables, it always did the same thing, in the same way (stock map, APR stage 1).

Boost, fuel, lambda, temps and everything measured was absolutely fine and showed no weirdness at this point in the run.

The only thing spotted was a deg of timing added at this point, and then backed out again. Logging resolution wasn't great as I was using VCDS.

I'm going to ask about on the APR forum too, but thought I would post here too.

 

[8YARWY]

Hello all,

I did some dyno runs yesterday which produced the outputs below. There was an odd dip in power/torque at around 5000rpm, which then recovered to where you'd expect the curve to end up.
Regardless of any other variables, it always did the same thing, in the same way (stock map, APR stage 1).

Boost, fuel, lambda, temps and everything measured was absolutely fine and showed no weirdness at this point in the run.

The only thing spotted was a deg of timing added at this point, and then backed out again. Logging resolution wasn't great as I was using VCDS.

I'm going to ask about on the APR forum too, but thought I would post here too.

View attachment 270234

Have you unplugged exhaust valves by any chance ?


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[wuta3]

Have you unplugged exhaust valves by any chance ?


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Nope they were plugged in, but on a valve controller. I watched back some footage, and they were set to open at 4k (as stock), as full-open mode mustve got bumped off when the operator disabled traction control (valve controller uses TC switch for mode select)

 

[8YARWY]

Nope they were plugged in, but on a valve controller. I watched back some footage, and they were set to open at 4k (as stock), as full-open mode mustve got bumped off when the operator disabled traction control (valve controller uses TC switch for mode select)

I’ve seen this on a Dyno run before when the valves were unplugged, they were then plugged back in and the dip went away.

Car pulled power to protect the engine as it thinks the valves are closed and doesn’t receive any signals to say any different.


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[wuta3]

I’ve seen this on a Dyno run before when the valves were unplugged, they were then plugged back in and the dip went away.

Car pulled power to protect the engine as it thinks the valves are closed and doesn’t receive any signals to say any different.


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Ah that'd make sense if the CETE valve controller got confused, as there was some rapid fire ESC button mashing before the runs, which may have confused the controller seeing as it piggy-backs that button signal for disable/always-open actuation. Usually it stores states based on drive mode.

If the CETE controller was in a weird state, perhaps though the valves opened at 4k (which I am 100% sure they did), the controller reported on CANBUS that the valves were closed (or didn't respond to requests).

I would've expected an error code of some kind with this though. Hmmmm.

 

[wuta3]

OK, so it turns out this is probably a combination of the APR map and CETE valve controller.

The APR map has different valve-open RPM points than the CETE controller when it "fakes" OEM mode or "off" mode. So the APR map is optimised for shift points earlier than standard, and the valve controller hijacks the APR lower valve-open points and moves them up the RPM range.

This results in similar engine protection kicking in as if your valves were stuck closed or the ECU gets confused or finds discrepency because valves don't open when it is mapped to expect.

I need to hit the dyno again and test this out.