Any idea why nitz's timing is always 1 or 2 degrees off from the timing in his ignition map? It seems to be 2 degrees off in the areas of the 1 count knock sums.

 

Ummmm....

 

Umm.. check the log. 1Byte Load is being used. Unless that's off and RPM is off I don't see how we are looking at the wrong cell.


When you say MUT33 is post map, does that mean interpolated timing and not just the timing value from that single cell?

REF:

 

We are using 1-byte load but... does it even matter what load we are using if we are logging the two MUT addresses for timing from the table and then actual timing? Doesn't what load/rpm we log become irrelevant because we are reading the "timing from the ignition table" value from a MUT address? Forgive my ignorance if I am incorrect.

I guess our question is, why and exactly what are the MUT 6 and 33 values a reading of specifically? And why are they different? (see the log nitz posted)

 

i think fosty was refereing to the bit about corrections...

its probably a iat correction, when its super cold OR hot you will get a reduced timing...

 

Do we know the algorithm for this correction? And you wrote previoustly "etc" when speaking about corrections. What other corrections apart from IAT is there on ignition timing?

And by IAT are you referring to the temp recorded at the MAF?

Nitz and I are in the Caribbean... so it is about 30c always.

 

there are a couple of maps - no algorithm...

just look up a thread by mattjin

 

MAF based IAT ignition correction.

 

You guys are stars!

So if my buddy was getting some heat soak, I can see at 34c he'd be having a degree pulled which look like what is happening in his logs.

Another question! Why are we seeing a degree of timing pulled for 1 knock sum? Does it round up?

 

Internally the calculation is to 0.35 degree based on the knock sum. What you put in the maps and what is in the logs is to the nearest degree.

I think actually getting the timing to align with what we can actually find tables and explanations for is great for an OEM ECU, even some aftermarket ECUs I had didn't align, just tuned on the trends anyway as we all usually do. I'm planning to desert to a 911 Turbo, but the understanding of their ECUs to enthusiasts just isn't there, and I'll miss that, but I don't want two cars and the Evo's manners and boy racer image are finally getting to me as a daily driver.

 

Understood John and thank you. Enjoy the 911T.. sounds lovely.

 

oooh nice.

yeah +1 on the community..

 

maybe you could just take the rear spoiler off, change the bonnet, and stay?

 

I don't really know what I want to be honest! I chose the Evo from an E46 M3 which I hated because of the lack of suspension travel on bumpy roads, but liked everything else. Before that I had a Scooby that I tuned hard, but the EJ257 was unreliable. I've considered everything from keeping the Evo and then getting a wafter for when I'm in that mood, to getting an all rounder like the 911, but I'm also slowing down, a few times a week I hit a twisty road with a 60 mph limit that when it is empty you could go much faster, but it risks police interest and consequences. Part of me just thinks I should buy a 530i and grow up, another keeps the Evo, and another blows a wedge of cash on a 911!

If they made the 335xi in right hand drive, I'd get one of those, but as it is, I have to handle the snow and farm tracks, so FWD or AWD is the way to go for me. You just can't get decent priced winter wheel and tyre packages here, and runflats on the 335i complicate it more, but that is still a tempting option that is cheap to run and can have a bit of fun without being insane like a fast Evo.

 

not my favourite evo, but if i were looking to tone it down while still keeping most of what i like about an evo i'd prolly go for a X. the black makes the gaping front grill a little less pronounced and with the right wheel & tyre package it could look very civilized. additionally, you know there will be many years of ecu disassembly to come which will keep you busy at night and us smiling by day.