ECUflash SD confusion

[smills1840]

First things first, I don't have anything needed to run SD yet with ecuflash because I'm not sure if I'll be able to figure it out. This may be part of the problem, since I can't see logs and try things out.

I've been researching SD using ceddymods for a while, but I've been experimenting in ecuflash with a rom I found on his site and I've practiced changing the scaling for the 4 bar MAP sensor, and messing with it's calibration. I've got that down, but I am completely and totally lost on the VE tables.

I know I'm going to need to log with the MAF and MAP sensor, but I'm not sure what I'll need to do from that point on. I know I'll need to build the SD map from the MAF log, but I don't know how I'm supposed to do that.

Does anyone have a link to a good tutorial (besides ceddy's) or some pointers before I spend all this money and get in over my head? Thanks!

 

[tkelly27]

It's really great that you have found out how to scale for a 4bar map sensor. I have had to help a lot of people do that.

I have always found the usage of VE to be a pain in the rear. You have to tune the maf, tune the engine on the maf, and then you finally get to tune the speed density. No stand alone or true speed density code ever makes you do this. You don't tune an AEM with a MAF first, you just jump straight into tuning the injector pulsewidths based on pressure and RPM.

On a DSM that still calculates load you are supposed to adjust the VE so that you are getting the same calculated load from the MAP sensor as you get from the MAF sensor. The goal of this is so that you can then tune the AFR tables and the spark tables based on calculated load you get from your logger.

What you would do is log real load, calculated load, boost, and RPM. You'll have a spot in the VE table with boost and RPM, and you'll know how far off you are with real load vs. calculated load. You can just solve for new ve with the following formula

newve/oldve = measured load/ calculated load.

if the measured load is bigger than calculated load you'll need a larger VE. If the measured load is less than calculated load you'll need less VE.

The other way you can do it is to flatten out the fuel table to something like 11.5 and match the AFR at all the load points using a wideband. This is a way to do it if you don't have a MAF installed.

Make sure you have the IAT set up too. It should effect calculated load. I have dealt with a few cars tuned without using them. You can do it, but it is better to have it.

I've never used either of these methods. I always flatten out the AFR table all to 14.7 in all maps and then tune using the VE. So instead of having an accurate load and going to look what AFR it should be I have it thinking it is getting a lot of load for rich, and less load for lean. I just can't stand tuning with the load table. The problem then becomes the spark lookup. If you're changing fuel by changing calculated load then the spot it looks up in the spark table changes too. You have to adjust spark through logged load values at a given boost and RPM.

I hope that makes sense.