Barry's Evoscan - Removing the Knock

[BraindG]

Now that i have evoscan installed, i have some questions, stupid as they may be...

On the Graphs and Maptracer menu, am i expected to input all the Power / Torque settings for the VR4? if so, what have others put in?

EDIT: now found this thread.

power torque.png

regarding knock count, i want to set an alarm (if recommended?) - What are other using here?

knock count.png

K, thats all for tonight

Thanks

EDIT: List of threads of relevance.

Evoscan Question - Discusses O2 Sensor reading 0.05856.
evoscan knock - anyone got some logs for comparison - discusses possible causes for knock.

[BraindG]

Graph question time...

Can someone explain to me why i jump to 15th gear at points?

weird gear graph.png

[BraindG]

Sorry, your going to hate me soon

Can someone explain why the fuel consumption is so erratic just before i start slowing? - is it cos i take foot of accelrator?

fuel consumption.png

[BraindG]

Sorry, your going to hate me soon

Can someone explain why the fuel consumption is so erratic just before i start slowing? - is it cos i take foot of accelrator?

fuel consumption.png

I've reviewed all 4 logs, what i notice is that when releasing the power (taking foot off pedal) there is a massive spike in fuel consumption - i'd have expected this for stamping on the pedal but not releasing - might have to start changing my driving habits..

[BraindG]

Last one for tonight, off to play with electronics now

i note alot of knocksum when flooring car as high as about 18 - is this the correct value to be measuring knock with? - and... should i be worried?

knock - speed - tps.png

[Kenneth]

Gear is usually calculated by RPM / Speed. It is only useful while in gear and the clutch engaged. As soon as that is not the case, the RPM becomes independent of speed and the gear calculation will be wrong.

Graph question time...

Can someone explain to me why i jump to 15th gear at points?

weird gear graph.png

[Kenneth]

How is fuel consumption being calculated? Do you have a VTA bov?

I've reviewed all 4 logs, what i notice is that when releasing the power (taking foot off pedal) there is a massive spike in fuel consumption - i'd have expected this for stamping on the pedal but not releasing - might have to start changing my driving habits..

[BraindG]

Gear is usually calculated by RPM / Speed. It is only useful while in gear and the clutch engaged. As soon as that is not the case, the RPM becomes independent of speed and the gear calculation will be wrong.

cheers Kenneth, very clear now - makes sense, thank you.

[Kenneth]

Yes, KnockSum is the correct value.

18 is bad. You should be aiming for 0. The OCCASIONAL count of 1 shouldn't be a problem though.

Last one for tonight, off to play with electronics now

i note alot of knocksum when flooring car as high as about 18 - is this the correct value to be measuring knock with? - and... should i be worried?

knock - speed - tps.png

[BraindG]

Yes, KnockSum is the correct value.

18 is bad. You should be aiming for 0. The OCCASIONAL count of 1 shouldn't be a problem though.

after some advise from Jason, i've been searching for "false knock" threads, found one here. Few things that could lead to false knock, dodgy clutch, maybe engine mounts (im changing both this weekend) also HT Leads and plugs, even possibly fuel filter or pump.

i'll lower boost tomorrow and do same experiment, then stay on lower boost for a while if it goes away.

[BraindG]

How is fuel consumption being calculated? Do you have a VTA bov?

[Speed]/(513*4*[InjDutyCycle]/100*0.015873)

[Kenneth]

Why does he think it could be false knock? If you are getting knocksum when flooring it, chances are that it is real knock. You should be trying to correct it as such. If you can't get rid of it, then start looking for false knock.

18 is high and about what you would expect if you put your boost up to 15psi with only a standard intercooler.

[BraindG]

Why does he think it could be false knock? If you are getting knocksum when flooring it, chances are that it is real knock. You should be trying to correct it as such. If you can't get rid of it, then start looking for false knock.

18 is high and about what you would expect if you put your boost up to 15psi with only a standard intercooler.

well in Barry's wee mind, dropping the boost may eliminate or rule this theory in? - if on lower boost im getting high knock, then i'd presume (under the same driving conditions, same stretch of road) its false knock.

p.s. im at 1.1 bar and on standard intercooler, 99 ron.

[Kenneth]

[Speed]/(513*4*[InjDutyCycle]/100*0.015873)

So I assume this is default for an evo and should be

[Speed] = RPM
513 = injector size (so not correct for a VR-4)
4 = Cylinder count (so should be 6)

I have no idea what 0.015873 is meant to be for though

I guess you will want to check that IDC and Speed are correct and are giving useful information. Might pay to log them next to your fuel consumption so you can bench check to see if the values are sane.
Also, if you are logging 2 byte values there is possible read errors (values change quicker than the MUT requests are sent so values can change between 2 different values being received to the logger)

[Kenneth]

1.1 bar with a standard intercooler and I can almost guarantee that it is real knock.

Yes, first step is to reduce boost. You can tune out the knock with ignition timing changes and/or fuel too.

false knock should NEVER be your first theory.

well in Barry's wee mind, dropping the boost may eliminate or rule this theory in? - if on lower boost im getting high knock, then i'd presume (under the same driving conditions, same stretch of road) its false knock.

p.s. im at 1.1 bar and on standard intercooler, 99 ron.

[BraindG]

So I assume this is default for an evo and should be

[Speed] = RPM
513 = injector size (so not correct for a VR-4)
4 = Cylinder count (so should be 6)

I have no idea what 0.015873 is meant to be for though

I guess you will want to check that IDC and Speed are correct and are giving useful information. Might pay to log them next to your fuel consumption so you can bench check to see if the values are sane.
Also, if you are logging 2 byte values there is possible read errors (values change quicker than the MUT requests are sent so values can change between 2 different values being received to the logger)

Ok so based on this thread, standard sizes are 390cc.

Im confused now actually, there are two calculations in evoscan.

29-05-2012 00-20-43.jpg

MPG (US) - [Speed]/(513*4*[InjDutyCycle]/100*0.015873)
Liters/100Kms - x*[InjPulseWidth]*20*6/[Speed]/1200

Firstly, i cant see how set one or the other as default and Secondly - neither much use to us here in the uk.

Anyone configured this for UK readings?

[BraindG]

Why does he think it could be false knock? If you are getting knocksum when flooring it, chances are that it is real knock. You should be trying to correct it as such. If you can't get rid of it, then start looking for false knock.

18 is high and about what you would expect if you put your boost up to 15psi with only a standard intercooler.

Tbh, we exchanged 2 text messages, wasn't really a full discussion

Anyways, looking closer, the high knock occurs after lifting of the gas to change gear and then it dissapears when gear engaged and i've floored it again - Having read Ben's thread (i'm no expert on detonation btw) i would have though knock occurs during load? - or am i looking at a build up of heat / sparks in bore between gear changes causing knock?

29-05-2012 00-25-30.png

Edit: Scratch that - i see now that there is a build up of knock leading up to the gear change, the slow decline in TPS is me easing off a little (chicken)

[Kenneth]

Injector duty cycle (IDC) is how much the injectors are open as a percentage. At 50% then the injectors are open 50% of the time, regardless of what frequency.

Injector pulse width (IPW) is how long they are open for this injector cycle. You need the frequency for this as it IPW * frequency is how much fuel get delivered in total.

IDC should actually be sufficient for tracking fuel usage changes. (Useful if you don't care about actual MPG figures)

[Kenneth]

If it is only on lift off, then it could be false knock. That graph resolution is much better than the first one

Do try reducing boost though as you want to eliminate that possibility first.

[BraindG]

If it is only on lift off, then it could be false knock. That graph resolution is much better than the first one

Do try reducing boost though as you want to eliminate that possibility first.

Will do, ill drop the boost to 0.9 and do the same run - so under "normal" knock conditions, would you expect to see them underload?

looking at those graphs, they come in as im easing off, but not dropping gas to change gear. looks like i wasnt planting pedal to floor between each gear change, rather slowly decreasing before gear change.