I've been datalogging since i've gotten my AP, hoping to post on to here or cobb forums for someone with the knowlege to be able to diagnose my car. I look at the charts and have no idea what i'm looking at.

It would be nice if somebody would do a 'Datalog tutorial for dummies' or something like that. From the searches i've done, tuners (or the people who have the ability to analyze these charts) tell you what's wrong, but rarely explain their reasoning, like which parameters showed a bad value, how it relates to the other parameters, etc.

I know probably the most important thing to keep an eye on is knock. One of my datalogs showed a knock of 2 on WOT at high RPM. I know that .35 = 1 so i've got like 6 i guess? What exactly is normal knock? Bad knock?

If someone with the knowlege can shed some light and do a little bit of explaining, it could eliminate the countless 'do my logs look right' threads around here.

My main question right now is, is my knock normal?

 

i know my knock isn't bad at all, i've been seeing posts of people up to 10 counts and people saying it's normal. But i still haven't had a definite answer of what values i should be seeing. People are also taking into account that the AP sometimes shows false knock values?

Is the datalog on the AP at all reliable for diagnosing knock issues?

 

anyone? With all these people running the ap and datalogging, i'd expect someone to at least know the basics... can't be that complicated no?

 

likewise! any n00b tutorial on what knock is acceptable etc?

 

are you using an OTS tune? which stage? from casual observation i hear stage 1 knocks, check updates on cobbs site or go to stage 2 instead. please verify that by searching here and checking requirements first.

i dont know about the AP's knock numbers but personally i wouldnt like to see more than the occasional 1-2 count knock sum on open source. if your knock count is 6, i would want to address that. especially if you have good gas and are still knocking because what happens if you get bad gas. that knock count is going to go up!

as far as what items to log... that is heavily dependent on what you are trying to address. you typically always log RPM, LOAD, and TPS otherwise you have no point of reference.

In your case you might be trying to pinpoint knock so you should log KNOCK and TIMING ADVANCE since timing most directly impacts knock you should also log AFR (wideband) if you have it since fuel controls the severity of knock. it's a shame most folks don't have that. I would log BOOST as well for good measure.

 

if you want good reading material, download Merlin's Guide to Tuning . it is based around EcuFlash rather than Cobb but the practices and fundamentals of tuning are sound. You can download the EcuFlash application and play around just to understand.

I know you can download AccessTuner if you own an AP as well so you should be able to make the correlation between the two programs pretty easily.

 

I'm using the most updated version of stage 1 93 on a bone stock evo. Momo, do you know how the AP's 'knock sum' value correlates with the opensource values? My AP shows 2, but i read somewhere to multiply that number by 3, or maybe that was for earlier versions of the AP... anyone know?

 

oh, then i believe it was updated if it is 'knock sum' and if so i would think it is the same as the open source counterpart.

i think the old value was .33 because it was 'knock retard' and each 3 counts of knock means reduce timing.


edit: this thread has some good points about stage 1 and knock that might relate to you.
https://www.evolutionm.net/forums/co...ccessport.html

 

Thanks for pointing me in the right direction! i'll read through it