Odd timing

Hi, I'm in the process of remaping my car and I'm trying to get the timing table smooth.

But I'm getting knock around 5500rpm and have to retard the timing to 1 degree so it doesn't knock. I know that the engine is sensitive to knock, but the timing is at about 9-7 around 4000rpm (where the turbo is almost at its peak boost), and 7 about 7000rpm but I have to retard the timing down to 1 at 5000-5500rpm to not get knock

The car is an EU Mitsubishi Colt with a 4G15T engine and a stock ECU that is reflashed via ECUflash. The JDM or ADM has an ECU that is a bit different compared to the EU Colt.

Some would say that it might be running lean at around 5500rpm but it was actually running very rich (10.5 AFR) and now 11-11.5. So it is not the fueling. When I have asked around, 7 in timing advance at around 7000rpm seems where it should be.

My question is what could cause this issue and what could be done?

The fuel I'm using is 98 octane

Josef,

Running the turbo agressively, causing high compressor outlet temperatures which the intercooler may not be able to keep up with would be my first guess, but have you confirmed there's actually knock present?

Does the knock go away if you drop the boost say 5 psi?

the turbo is not that big so it should be able to handle more because I'm not pushing the turbo either. However it is not like the engine cannot handle more timing, it's just the timing is very low as 5500rpm, before that where the cylinder pressure is the highest it has more timing and after that it has more timing. It's just at 5500rpm that I have to run low timing.

Have you verfied that there is zero timing drift and that base timing is correct, by the use of a timing light?

Not sure what you mean by base timing, but I think the table from the beginning was based on the stock oem timing and then reduced in order to start conservative. But I got higher number in knock sum compared to the timing advance, the thing is that my car was remaped earlier with ecutek bit that software doesn't support higher power which is why I switched to ecuflash. Since then I have a bit bigger turbo.

Hi Jora

By Base Timing I meant, does a timing angle of ie. 10 degrees in the software actially show at 10 degrees at the crankshaft when checking it with a timing light?

And when you lock those 10 degrees in the software, does that angle stay rock Solid when you rev up the rpm to ie. 4000 stationary?

10 is only an example. Use whatever angle you consider safe for this test.

Ok, not sure as I don't have that kind of equipment.

But it should if the it is hardware dependent as my car was remaped before and didn't have the issue I'm having.

And shouldn't this be visible in the logs?