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Knock review

Posted: Mon Jun 06, 2022 12:15 pm
by finsky
Hello,

I'm very new to tuning but have been following courses intensively for the past few weeks and finally jumped into Kpro. I'm looking for some advice about my current logs.

I bought my EG with the following setup:
- K20A2 (PRA)
- Drag Cartel 2.2 cams
- Bosch 550cc EV14 injectors
- ACL Trimetal conrod bearings
- NGK Iridium spark plugs
- RRC manifold with CAI intake
- 76mm ... exhaust
- Walbro 255LPH fuel pump
- Hybrid Racing fuel rail
- IACV delete
- Exedy Hyper Single clutch with lightweight flywheel
- stiffer Hasport engine mounts
- ...

The car was tuned exclusively for E85, but I was told the tune was not finished and the car was running rich/safe on open loop only with no ignition timing added vs. regular gas. My goal is to make it flexfuel and finish what I can, so basically what I did is I plugged an ethanol sensor, I drained the car and put 98 octane fuel in it, I opened the current tune and adjusted fuel trims, and then later added closed loop and flexfuel in the parameters.

I noticed the knock sensor was disabled. When I enabled it, I started seeing the knock count increase in the following scenarios :
- somewhat randomly on part throttle at 2000-4000 rpms.
- every other time when going WOT to 8k rpm and right when I let off the gas to decelerate or switch gears.

I tried pulling a lot of timing, running the stock tune... no change. Should this be considered false knock ? I suspect the previous tuner disabled the knock sensor on purpose because of this, and I've started adjusting the knock sensor sensitivity for part throttle knock, but I'm especially worried about the knock spike I get at WOT. What do you think ? I lack the experience. Also, I do not currently have access to a dyno.

Thanks a lot :)

Re: Knock review

Posted: Wed Jun 08, 2022 8:26 pm
by CalibratEd
I looked over the datalog and see where you are getting knock. If you have reduced timing in that area and knock has not been reduced it is likely that it is false knock. If you briefly search the cams you are running, they have been shown to cause false knock. I assume the tuner turned the knock sensor off so knock would not show. Was there any reason the tune was not completed?

-Ed

Re: Knock review

Posted: Thu Jun 09, 2022 8:50 am
by finsky
Hi Ed,

Thank you for your input, it's really appreciated and reassuring.

The previous owner sold the car before the tune was finished for unrelated reasons (or at least so I was told).

I guess it's best I check with a det can just for peace of mind. I'll update this post if there's anything new.

Re: Knock review

Posted: Fri Jun 10, 2022 7:56 am
by CalibratEd
finsky wrote: Thu Jun 09, 2022 8:50 am Hi Ed,

Thank you for your input, it's really appreciated and reassuring.

The previous owner sold the car before the tune was finished for unrelated reasons (or at least so I was told).

I guess it's best I check with a det can just for peace of mind. I'll update this post if there's anything new.
No problem.

-Ed