Turbo knock during spool up

[yzf219]

Wondering if anyone can help me with this please,

My car is a 2013MY BO1C ROM, turbocharged (GTX3076R), DW700 injectors, GM 3 bar map, self tuned (Ecutek), 3port MAC, 93 octane shell (Canada), stock catback, stock front pipe.

I'm noticing that I have been getting knock in the 0.8-1.3 load range right when the turbo is spooling up. I've never noticed this before as I had a 3psi wg spring previously and I recently just installed a 5psi spring causing the turbo to spool up much earlier. I figured the knock was just from the earlier spool so I pull some timing from the effected knock areas, however despite the timing reduction in the ignition base map I am still getting knock, it seems to be slightly better after the timing reduction, but I am at the point where I have so little timing in this area and it still knocks. Tried adding some fuel and increasing the DI, still knocks, blended some ethanol into the gas to make an E30 blend, still knocks, knocks even when I am free revving it with the clutch in. I am at a complete loss on what to do next. Car runs great at full throttle no knock whatsoever. Attached is a copy of the datalogs with the car on 93 octane, I don't have logs of the car with e30.

Could this be low speed preignition? The current oil I have in the car is just API SN oil which isn't LSPI rated, and the oil has 5000kms on it. I am hoping that the knock is due to the oil I am using as the car didn't really knock before, perhaps the oil degraded a bit? When the car had no knock the ambient temps were also much colder, 0-5c, now spring is here the ambient temps 8-12c.

Can anyone provide insight please and thanks.

[yzf219]

Originally Posted by yzf219

Wondering if anyone can help me with this please,

My car is a 2013MY BO1C ROM, turbocharged (GTX3076R), DW700 injectors, GM 3 bar map, self tuned (Ecutek), 3port MAC, 93 octane shell (Canada), stock catback, stock front pipe.

I'm noticing that I have been getting knock in the 0.8-1.3 load range right when the turbo is spooling up. I've never noticed this before as I had a 3psi wg spring previously and I recently just installed a 5psi spring causing the turbo to spool up much earlier. I figured the knock was just from the earlier spool so I pull some timing from the effected knock areas, however despite the timing reduction in the ignition base map I am still getting knock, it seems to be slightly better after the timing reduction, but I am at the point where I have so little timing in this area and it still knocks. Tried adding some fuel and increasing the DI, still knocks, blended some ethanol into the gas to make an E30 blend, still knocks, knocks even when I am free revving it with the clutch in. I am at a complete loss on what to do next. Car runs great at full throttle no knock whatsoever. Attached is a copy of the datalogs with the car on 93 octane, I don't have logs of the car with e30.

Could this be low speed preignition? The current oil I have in the car is just API SN oil which isn't LSPI rated, and the oil has 5000kms on it. I am hoping that the knock is due to the oil I am using as the car didn't really knock before, perhaps the oil degraded a bit? When the car had no knock the ambient temps were also much colder, 0-5c, now spring is here the ambient temps 8-12c.

Can anyone provide insight please and thanks.

Update if anyone is interested, I put the stock avcs tables back in the rom and the knock correction is completely eliminated, I noticed with the old avcs tables when I was revving the car I could hear a metallic rattle that has been well documented on this forum, the rattle coincided with the knock corrections. My car also has stiffer engine and transmission mounts, I'm thinking that the stiffer mounts transmitted the noise from the avcs which tripped the knock sensor, going to try a softer trans mount.

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[DarkPira7e]

Originally Posted by yzf219

Update if anyone is interested, I put the stock avcs tables back in the rom and the knock correction is completely eliminated, I noticed with the old avcs tables when I was revving the car I could hear a metallic rattle that has been well documented on this forum, the rattle coincided with the knock corrections. My car also has stiffer engine and transmission mounts, I'm thinking that the stiffer mounts transmitted the noise from the avcs which tripped the knock sensor, going to try a softer trans mount.

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Stock AVCS tables from B01C? What's the name of the tables you changes exactly?

[yzf219]

Originally Posted by DarkPira7e

Stock AVCS tables from B01C? What's the name of the tables you changes exactly?

Yes I put the stock avcs tables from b01c.
Intake/exhaust cam advance angle high/low det was the name. Intake has 2 tables high det and low det. Same goes for the exhaust.

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[yzf219]

Just another update, the knock corrections are back, changing the vvt tables didn't help, changing to an lspi approved oil also didn't help.

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[tomm.brz]

try advance DI injection angle at low rpm high load
i put 320 instead of 300
try also advancing the PI angle under 3200-3400rpm with a custom map, PI timing is fixed at 360 but you can advance to say 380 or 390 or 400 with a custom map
Do not make it too rich at low rpm high load and when it is in spooling zone, it doesnt like when it s too rich
So if you lower ignition timings knock don t go away?

Sorry still haven t seen the log as it is too big to look at that with my phone at the mom

[yzf219]

Originally Posted by tomm.brz

try advance DI injection angle at low rpm high load
i put 320 instead of 300
try also advancing the PI angle under 3200-3400rpm with a custom map, PI timing is fixed at 360 but you can advance to say 380 or 390 or 400 with a custom map
Do not make it too rich at low rpm high load and when it is in spooling zone, it doesnt like when it s too rich
So if you lower ignition timings knock don t go away?

Sorry still haven t seen the log as it is too big to look at that with my phone at the mom

Hi Tomm,

I was actually just reading your post on you solving a similar issue.

I appreciate your suggestions, I'll try the pi and di angle changes. I actually just got done updating the tune and leaned the areas around 0.8-1.2load 2600-3200rpm to around 12.7 Afr, haven't test driven yet though.

And that is correct, altering ignition timings doesn't make any difference to the knock correction.

Thanks again for your help!

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[tomm.brz]

yeah this car doesn t have the ability to split DI into multiple injections which would help so theoretic goal is to advance PI angle so that it can sit more on closed valves and also more chances to vaporize better
Also the retarded DI angle that even oem tune has at low rpm high load causes more piston impingement and wall wetting and that s worse for lspi

interesting is subaru on late gen1 Euro advanced the DI a lot everywhere

Anyway also the opposite could actually work somehow, see Cosworth that for his auoercharger retards a lot DI angle ( like around 260-280 instead of 300) and also uses very low cam timing values and little overlap.... i guess what works, works.

How much PI have you setup? you can PM your tune if you want i ll take a look together with the log

[yzf219]

Originally Posted by tomm.brz

yeah this car doesn t have the ability to split DI into multiple injections which would help so theoretic goal is to advance PI angle so that it can sit more on closed valves and also more chances to vaporize better
Also the retarded DI angle that even oem tune has at low rpm high load causes more piston impingement and wall wetting and that s worse for lspi

interesting is subaru on late gen1 Euro advanced the DI a lot everywhere

Anyway also the opposite could actually work somehow, see Cosworth that for his auoercharger retards a lot DI angle ( like around 260-280 instead of 300) and also uses very low cam timing values and little overlap.... i guess what works, works.

How much PI have you setup? you can PM your tune if you want i ll take a look together with the log

Pm'd you thanks for helping!