95 replies to this topic

[Johnboyhgt]

Have you got an image of the knock from logging session we can see ?

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[Fordy]

If you want to look at any particular sections in more detail or any other corresponding data then let me know

Attached Files

•  Knock Retard Log.JPG   53.79KB   7 downloads

[Johnboyhgt]

a close up of the cluster around 1500 would be useful.

[Fordy]

Anything else then please let me know

Attached Files

•  Knock Retard Log 2.JPG   42.58KB   8 downloads

[Johnboyhgt]

Yep that's definitely knock, can you don the same with the intake temperature, same point please.

[Fordy]

Intake Temp

Attached Files

•  Intake Temps 2.JPG   40.05KB   8 downloads

[Johnboyhgt]

Ok so looking at those two thinks occur.

 

1. Your inlet temps are high and to deal with this the ecu first reduces ignition timing and then as a last ditch effort adds more fuel to reduce temperatures, hence you need some head height on your injector duty cycle.

 

2. You have actual knock, as it builds up just as your  image shows. any other triggering of the sensor would be a spike over a short timeframe. a tuner will say the same.

 

 

[smiley]

Can we have the full log, so we can recalculate the spikes back to the rpm/pka location in the map.

If hosting is difficult, ping me for your email, and i will host it for you.

[Fordy]

Ok so looking at those two thinks occur.

 

1. Your inlet temps are high and to deal with this the ecu first reduces ignition timing and then as a last ditch effort adds more fuel to reduce temperatures, hence you need some head height on your injector duty cycle.

 

2. You have actual knock, as it builds up just as your  image shows. any other triggering of the sensor would be a spike over a short timeframe. a tuner will say the same.

 

Thanks for that mate.

 

1. Based on those temps what pulley size would you use?

 

2. Just to confirm, are you saying that the knock is being caused by the inlet temps?

[Johnboyhgt]

Based on you're current mods I'd say you're future direction is either 3.0 or 3.1" pulleys, LSJ throttle body, bigger injectors and stage 2 cams. that will give you 300-315bhp. Any smaller on the pulley produces heat and gains no more volumetric efficiency on the m62sc.

 

You could fit one of those pulleys and limit max rpm so you don't top out the injectors.

 

I cannot conform that the knock is caused by the heat or injector sizing without physically testing the engine myself - you may have piston slap for all I know. However my assumptions are based on what appears to be a mismatched set up and personal experiences.

 

Also I'm assuming that you have done a good fuel learn, and given your ignition problems ignition learn too.

 

Feel free to send Smiley and myself you're calibration to see if we can help further.

[Johnboyhgt]

Also, Peter does a fantastic job with base maps but he is to some degree taking an educated guess when building a base map, that job in this case is harder because of you're unusual set up. 

 

Also transient settings wont help your cause, if its fluffy or hesitant on initial wide open throttle then they might, but that,s not what you describe.

[smiley]

The full log.

http://www.speedster...mages/fordy.zip

 

[Fordy]

The full log.

http://www.speedster...mages/fordy.zip

 

Thanks Stefan

[Johnboyhgt]

Having looked at this. Fuel learn then Ignition learn. You'd be surprised that lowering ignition by a few degrees sometimes less prevents lots more knock being created.

[Zoobeef]

Most has been said but I echo up the injectors, I maxed out blue vxr ones at 250+bhp. Even after cleaning and flow testing to make sure they were right.

The bigger ones than that are cheap enough.

 

Bigger pulley, a 3 or 3.1 is good enough for over 300. Again cheap fix.

 

Bigger TB, again cheap fix.

 

Cams and porting would be the other things but the cost goes up.

 

I'd change those first things though and see what happens before trying to fix something that may be a result of one of those.

[smiley]

This is where the knock is happening.

 

Your fuel is only at 90% on 2 of the 19 knock spikes from your log.
The rest is way below. So injector size is better for future usage, it does not seem to be the root cause.
 

Either this is false knock, or when looking at how early in rpm (2600-4400) it happens, but on impressive boost (0.5 to 0.8 bar) your system is not happy with to much pressure.

 

If it is false knock, one of the Dutch conversions used a very very thin gasket on his knock sensor to overcome that.
Not sure of this could be an option. Let's park that as plan C for now, and give some other time to go over your logfile.

 

Edited by smiley, 07 July 2020 - 05:13 PM.

[chris_uk]

i can't see it being the injectors, i used VXR blue injectors and was getting over 300bhp (albeit at 100% duty, luke got 316bhp) 

 

[smiley]

Peter once explained to me that injectors cannot see beyond 90%, and are just fully open  as from there.
Hence the preference to stay way beyond that.

[chris_uk]

yes that is correct, i seem to recall on the stage 2ish conversions i did the injector duty sat around 60/70%. 

im trying to find a log.

[chris_uk]

yes that is correct, i seem to recall on the stage 2ish conversions i did the injector duty sat around 60/70%. 

im trying to find a log.