Lean Cruise Setup for Australia & New Zealand

[JohnL]

Can you increase the timing with the leaner AFR on the lean cruise tune?

The leaner mixture will want more advance. My wife's VS Ecotech V6 used to have a factor lean cruise AFR of about 17.6 IIRC and a heap of timing.

John

[The Alchemist]

One of my good customers has come back to report on an extra 100km per tank on a trip (550km PER TANK) from what he used to get and figures in the mid 10's per 100km on the fuel trip meter which is pretty good as he used to get mid 12's before the tuning.
Very happy

[Tordne]

Shit! I'm lucky to get 400 km per tank around town

[GMPX]

That much

[The Alchemist]

Well that was on a trip on the open road though......I'll ask him whats the go around town but its hard to get a good estimate as he travels a lot in his job you see. He is very happy with the mileage though, what do you guys get on the open road....apart from tickets ?

[macca_779]

Thought I would post up what settings I use for lean cruise on the cars I tune. I have worked up to these settings so its by no means a stab in the dark. I was running as lean as 16.1:1 in my car for 15000k's, I pulled out the plugs and they were in good condition, so now I'm running as lean as 16.3:1 I use b3647 in my car but here is a screen shot of a customers car utilising b3639. I've also attached an excel spreadsheet that I use to convert EQ to AFR for calculating these kind of things.

[The Alchemist]

Hey Macca, thats great.....very similar figures here. I use around 0.07 to 0.09 depending on the car and how good I've tuned the VE table Small changes makes a big difference to the AFR eh?
I run around 15.5 to 15.2 for lean cruise but I creep it up to 2400 rpm though. Cheers for that.

Mike

[macca_779]

yeah as you can see i don't bother with it above 2000. The way I see it, if your up there you aren't cruising anymore. Thats for an M6 anyway. You can go heaps leaner mate. Try 16:1 and add about 6 deg to the apporpriate segments in the upper timing table.

[The Alchemist]

will do, haven't played around with higher timing figures during lean cruise yet I run the usual 38 to 40 degrees. I see the newer E38's run up to 44 degrees at light cruise. \
With the more timing does this allow you to lean it out further without lean surge happening?

Mike

[macca_779]

will do, haven't played around with higher timing figures during lean cruise yet I run the usual 38 to 40 degrees. I see the newer E38's run up to 44 degrees at light cruise. \
With the more timing does this allow you to lean it out further without lean surge happening?

Mike

i havent suffered any surging from running this lean. But yes with a leaner mixture you can run more timing