What’s the best way to fine tune the target A/F ratio table in XFI? I’ve used the recommended settings from the chart in the help file but I would like dial it in for my motor. My motor cruises fine at 14.7 and even at 15.0 but how do I know if that is to lean or not lean enough. Could I use EGT readings or is there a cheaper way?
What’s the best way to fine tune the target A/F ratio table in XFI?
- Thread starter Cobia245
- Start date
- Joined
- May 28, 2001
How about reading the plugs??
Reading plugs is fine at the track but it’s hard on a daily driver you’d have to run the car at a low cruse speed read the plugs, mid speed read the plugs, and so on and so on. I was thinking with all the technology out there now there’s got to be an easier way.
generally when tuneing for lean cruise @ a light load you can get away with 14.7-15.7 with no problems. The best way to find out what ypu car like at a light load it to try it. If the car starts running rough or has a fish nibble feel to it. you too lean. I wouldn't worry to much about melting anything by running it lean @ a light load. I have measured EGT's and after 14.5 they actually start to cool off due to there not being much fuel there to burn to get hot.
Also one thing to note as well when doing the lean cruise you might need to add some more timing to give the leaner charge a chance to light off in the cylinder. thus it helps makie the engine run smoother as well.
I have my timing in 40 degree range @ light cruise with A/F 15.5. another thing you can look at is the vac gauge.
Your right reading plugs is great @ the track but @ cruise rpms and stuff that will do ya no good.
Also one thing to note as well when doing the lean cruise you might need to add some more timing to give the leaner charge a chance to light off in the cylinder. thus it helps makie the engine run smoother as well.
I have my timing in 40 degree range @ light cruise with A/F 15.5. another thing you can look at is the vac gauge.
Your right reading plugs is great @ the track but @ cruise rpms and stuff that will do ya no good.
Thanks SloGn.
When tuning with the vac gauge are you tuning to highest vac at that load?
Also would you recommend a real vac gauge or would reading the map sen. work just as good?
you can use the map or the vac gauge on your boost/vac gauge. yes i would tune to the highest reading @ a given load.
DiverDavies
Diver Davies
- Joined
- Sep 10, 2008
me too me too.
I also have the fast sys , ta49,and pretty much the same comb. 1 ect. 43.5 (009) inj. Im also trying to tune my car for daily driving. are you running alcohol?My car is dieing when i shift from gear to gear sometimes. other small things id like to tune out but i love the fast sys.
I also have the fast sys , ta49,and pretty much the same comb. 1 ect. 43.5 (009) inj. Im also trying to tune my car for daily driving. are you running alcohol?My car is dieing when i shift from gear to gear sometimes. other small things id like to tune out but i love the fast sys.
UR50SLO
The Reaper
- Joined
- Jun 12, 2001
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What's nice about the XFI vs Classic FAST is the ability to skew the load scaler.
(Move the left side of the table up/down)
On our classic you have basicly -15 to 0vacc then 0 to 15psi then 15 to 30 (Load on left)
On your XFI you can enter in where you want the load to be... (meaning if you desire more numbers/load map you can choose to make alot of them for -15 to 0 then from there you can really dial in your fuel table for drivabilty.
I need the Easter Bunny to drop me off a XFI to replace my Classic.
~Scott
Slow GN is exactly on the right track for drivabilty.. and good MPG.
What's nice about the XFI vs Classic FAST is the ability to skew the load scaler.
(Move the left side of the table up/down)
On our classic you have basicly -15 to 0vacc then 0 to 15psi then 15 to 30 (Load on left)
On your XFI you can enter in where you want the load to be... (meaning if you desire more numbers/load map you can choose to make alot of them for -15 to 0 then from there you can really dial in your fuel table for drivabilty.
I need the Easter Bunny to drop me off a XFI to replace my Classic.
~Scott
Slow GN is exactly on the right track for drivabilty.. and good MPG.