Knock at 60% throttle in 2nd gear and up around 4000rpms

[EfiniX]

I've got the guys at English Racing noodling this one right now, but I thought I would put it to the community as well as I'm very keen to learn more about how my car works and runs. I'm an engineer, but my computer+car experience is minimal. Right now I'm working with the following in terms of engine:

Rebuilt, hot tanked w/ .5 overbore and evo bits
3" exhaust Fujitsubo
Boost controller Hallman manual
Fuel Pump Walbro 255 Fuel pump
Intake K&N element with MAF adaptor
Downpipe 2.5" custom
Catalytic Converter high-flow/flanged
Manifold 2g ported
Turbo 20g
Camshafts HKS 264/264 Intake/Exhaust
Fuel injectors 1000cc
ETS Intercooler kit ETS GVR4 kit
DSMLink v3 DSMLink V3
Wideband kit Innovate

I'm running right around 20psi on 92oct. One thing that jumps right out is that I seem to be showing way more flow on my injectors then I would expect, given they are 1000cc. I'm guessing this is because the injector flow is a bit more nebulous than I'm expecting. Still, I'm out in the woods on all of this right now.

Thoughts?

 

[alansupra94]

What kind of fuel pressure regulator are you running? That 255lph could be overrunning it.

 

[EfiniX]

No, actually, and I've been wondering for months now if that's the next thing I should be looking at. Are you suggesting that this could be the cause of my injectors showing 1000cc+ output, the cause of my knock, or both?

 

[brisvr4]

Where is the knock starting? It looks to be starting around 3000?
Do you have link set to ignore knock under about 3000rpm and 30% throttle

Also, I believe that the fuel flow figure that you are seeing is the total flow for all 4 injectors.

 

[Dan D]

Anytime I've battled part/mid throttle knock it has been a problem with the transition from closed to open loop. What I figured out after a lot of head scratching and reviewing logs is when I would get into the throttle 40-50% from anywhere between 3K-4K rpm, the entry point into the open loop fuel table was too lean and my timing table had big jumps from the lowest two rows into the higher rows. Basically - with 9:1 compression and a small turbo (E316G) I had too much air too quickly and the fuel and timing didn't keep up fast enough.

This would result in spool, rpm climbing and then sudden knock in the high 3K to low 4K range. Once I pivoted a handful of logs and traced where I was in the map during the event and more importantly where I had just been in map before the knock started I realized the transition from closed to open loop was too aggressive

Solution for me: I lowered the close loop airflow points so I went open loop a little earlier and then touched up the timing and fuel maps to create a more gradual transition.

BTW: Is the wideband value shown in your logs valid? I see a lot of jagged line changes where it appears to go open loop and the wideband seems erratic and lean.

 

[EfiniX]

I don't have a reason to believe the LC1WB isn't putting out the right output. I did just have it installed and I trust the guys at English to,do it right, so if something is goofy, it's going to be on either the ECU-side (they did rebuild the harness, so I'm sure that's fine), or somewhere else.

Universally, I'm being told I'm too lean when my boost hits. What I need to do now is do some reading and watch some videos as I'm new to tuning and I'm going to have to know this stuff.

Any more pointers would be greatly appreciated.