E40 LS2 Cruise Tuning

[jmsmotorsport]

Playing with a E40 LS2 and am working on improving economy around cruise. What is to lean when it comes to cruise AFR and the only way I can see achieving this is by in the B0146 in the 30-65Kpa area at 144-176 degrees celcius IVT. Now I have gone to a factor .9 so when this is combined with the B0141 of 10.00 I get a EQ of .9 bringing the AFR to 16.40 is this to lean? Will doing this cause me any other issues in this map area when not cruising? or how do other people increase cruise economy without the lean cruise tables that we have in the aussie ls1 pcm.

[joecar]

Poat your tune.

~Moderator~

[jmsmotorsport]

20855

There you go Joe. I guess I'm trying to achieve the same as what the LS1 lean cruise tables achieve.

[joecar]

Yes, I see the same as what you said, manipulate B0146... or, B0148 might be easier, it gives you MAP vs RPM control;

it seems to me that you will also have to edit B0149.

It means you would run OL all the time.


I would try several factors in the range 0.90 to 0.95 to see which the engine likes better.




(( lol, it always freaks me out when I see B0141 set at EQR 10.0 in the E40 files, and then I remember that GM scaled this by setting B0146 to something like 0.10 ))

[jmsmotorsport]

Yes you would be right that B0149 would need to be modified, this would explain why when I tested I only got as low as EQ 1 and not into the .095 that I had put in B0146, B0148 I agree would be easier as it doesn't involve using the IVT numbers,

I didn't think about the OL part, what table would be used for CL cruise fuelling?

Yes it took me by surprise when I first set it up for OL VE tuning and it had 10s in there until I worked out the whole picture and how it works out AFR from the multiple tables.

[joecar]

That's the problem, when you use CL it will not be running from the OL fueling tables, so you wouldn't be able to do LC like that.


On the LS1B tunes, sometimes you could play with the O2 Switch Voltage (mV) table to achieve CL at leaner than stoich... but I don't see this table in the E40 tunes.