I have an EDM '06 GSR in Dubai. Max air temps in my log show 46 deg C / 115 deg F.

I'm running 20psi, 98ron.

ZT2 used to log boost & AFR (sensor in rear 02).

Restrictor mod done to raise boost, otherwise the car is bone stock.

The below are the changed cells after working out most of the knock, the rest is purely the stock map.

AFR map as yet untouched from stock (I figure keeping it rich will help with cooling).

The modified JDM RS MIVEC map (from this forum) is used.

Even with the below timing map I get occasional, but consistent knock, mostly 1's and 2's, and primarily under partial throttle stuff (which is very annoying). Normal 3rd/4th gear pulls usually pull cleanly.

My question is that I seem to have to run far more retarded timing than I generally see other people are running on the same fuel and boost. I know comparisons aren't easy, but as a general trend it seems that way.

Is this purely because of the heat?

The car feels ok, but a bit flat.

I thought perhaps turning off lean spool and getting a bit more fuel in at spool/partial throttle might allow me to run more timing.

I want to run more boost, but want some assurance first.

Any ideas/tips/tellings-off welcome.

 

I've carried on pulling timing to work out knock in low load, partial throttle areas, but doesn't seem to make a difference. Reading a few other posts it potentially seems like phantom knock.

Went back to stock timing map, with lean spool disabled, but no change. Still strings of 1's, 2's and some 3's, always in the range 2-3k, partial throttle.

Pulling 3rd or 4th gears is usually knock free. It seems only to happen on cruise, say 50%TPS, 5th and 6th gear stuff or from standstill.

Any ideas? Phantom?

I'd post on the uk MLR (I'm English), but they don't post timing maps like you guys do.


Cheers

Toby

 

Have you read merlins tuning guide? He has some stuff on partial throttle knock.

Higher ambient heat can cause more knock.

What loads are you hitting at 5000 rpms and above?

 

Above 5k rpm it hits 220/230, pretty much knock free (even on the stock timing map).

I've read some people having similar issues - particularly when pulling away from standstill. When I pull away from lights, going from 0-3k rpm slowly at no more than 50% TPS the below strings of 1's,2's,3's and 4's pop up.

Agressively retarding the timing will get rid of the 3's and 4's, but the 1's and 2's seem here to stay.

I'd ignore them if there weren't so many hits of knock, i'm getting a months worth of 'harmless' knock in a single drive...

 

well alot of times the car will knock the first run, then the second and third runs it will only have 1 or 2 counts.

are you doing 3 consecutive runs?

i wouldnt worry about the the knock below the 50% load. its such low load its not really doing any damage unless your getting 9 or more counts

 

Are you pulling advance from the first spark map, or the second, or both?

 

I make all 3 high oct timing maps the same. I've even tried making all 6 maps the same, just in case.

At 2.5-3k the knock alarm on the laptop chimes away, I can almost play tunes with it...