HELP: Knock from Cyl 2 from maps

FlashPro questions & answers specific to the 2006-2011 Americas Civic Si
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Barq
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Joined: Thu Aug 27, 2009 8:36 pm

HELP: Knock from Cyl 2 from maps

Post by Barq »

My only mod is a T1R intake. I've tried a bunch of the AFM and MAP tunes on the car and they all seem to be causing cylinder 2 to knock and sometimes cylinder 3. Something like 20 knocks in 5 minutes.

It happens during acceleration from low rpms, if I feather it it does not knock. When I give it more gas it knocks.

I then used the AEM SRI MAP tune and trimmed the cylinders ignition individually in the calibrations tab to -5, -9, -8, -5. This got rid of most of the knock. Did a 10 minute datalog and only counted 2 knocks from cylinder 2. However, the car vibrated a bit when I turned it on the first time but went away. I also get this gut feeling that something is not right by doing this.

However, I'm not sure if this is an indication of a deeper problem and I am not sure if it's safe to reduce the knock by that much individually.

Is there a better way of getting rid of knock from cylinder 2? I'm trying to get rid of the knock before I touch the fuel tables, then advance the ignition again to tune the knock out from the ignition tables after.

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Hondata
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Post by Hondata »

Cylinder #2 & 3 always produce more knock than the others. 20 knocks in 5 minutes is acceptable. You should not need to retard the ignition 9 degrees to remove the knock.

Make a datalog and find where the knock count increases. Decrease the ignition timing for the tables just in those areas. Also consider your intake temperatures - how much above ambient are they?
Hondata

Barq
Posts: 9
Joined: Thu Aug 27, 2009 8:36 pm

Post by Barq »

The IAT was at around 89 F to 100 F. The temperature outside was around 24 - 26 C which is about 78 F.

Taking out the knock from certain areas was my original plan, but I just freaked out when I could actually hear the pinging everytime I accelerated from a stop.

Which basemap would you recommend I started from? I'm not sure if this intake behaves like a SRI or a CAI. The T1R intake is just a smoothed out airbox with a different charge pipe and a intake scoop that replaces the resonator.

Edit:I also made some slight modifications to the intake. I cut out the veins in the lower portion of the airbox (stock lower portion of airbox was reused for this intake), and I put a rubber spacer on my upper radiator hose because it was touching the charge pipe, the charge pipe is cool to the touch now at all times.

Barq
Posts: 9
Joined: Thu Aug 27, 2009 8:36 pm

Post by Barq »

Just an update.

Started off with the K&N SRI MAP tune since I had logged a previous 3rd WOT and the AF was close to optimal. Fixed the knock by datalogging and retarding the ignition knock by knock. My near final tune, I logged about 10 knocks driving accross the entire city with everything from hills and A/C to 1500 rpm 3rd gear acceleration.

A lot of the knock was coming from 0 degree and 15 degree tables. I also had to stop about every 2 blocks for the first 7 trials because it was that bad.

Thanks Hondata for the quick replies. Although the tune seemed to lose it's bite every time I retarded the ignition, it still felt great in the end!

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