Lean Burn Cruise Step on in!

[Daniel Jost]

Ok guys last year I started doing some Lean burn cruise tuning on my car just screwing around. With the MS3x I am able to switch tunes on the fly so I can run a pretty lean AFR and higher timing on the highway. I road trip my car a lot so I could find this to be pretty beneficial for highway MPG.

Has anyone else screwed with this? Just wanted to start something up here and get some of our experienced tuners opinions on what they found to be a good AFR/Timing?

IIRC I was running somewhere in the area of 15.8-16 AFR and mid-high 20's for timing and was not picking up any detonation or poor running and EGTs were around 1000*. Most people say to keep on going until you expecience pinging, power loss, or high EGTs.

Opinions, Bad/Good Experiences anyone?

,Dan

 

[kidglok]

ive lean cruised at 16:1 a/f and 40* timing, but i do not have an egt meter and was a little nervous about the temps getting hot.

 

[Jerryl]

Just looked at an old log with TT SD Chip, May 2008
Cruising at 64 mph, 16.5-18.1 AFR, about 8.5“ vacuum, TPS 1.01V, 39-42.7 timing, no EGT at that time.
As flat as a road I could find . . . .Vehicle speed very steady for about 45 sec.

 

[Rafs-T-Type]

I run around 18 AFR and leaner and don't have any EGT issues.

 

[Daniel Jost]

I have heard of many others on the MSextra forums running in the 18's as well, but with turbo buicks being what they are I didn't know if they would like that.

,Dan

 

[SloGN]

from what i have found is the leaner the charge with low loads the timing needs to be advanced more to help with the fish nibble /nervous feeling out of the engine.

Also as you lean out the engine / advance the timing the EGT's should go down.

In my FAST i run in the ball park of 16.5 with timing in the mid 40's and it has no problems with tipping the pedal and going.


The fast wideband stopps reading at 15.97 A/F But i also have a AEM wideband so i can read the A/F in car without the laptop. so i use that on my lean cruise set-up.

 

[Daniel Jost]

This is good info guys, good input.

,Dan