MS tuners, what are your cruising AFR's?

[deadly_sleeper]

So I've been using Tuner Studio, put in my target AFR's and have let it tune my map for me, only thing I'm concerned about is that I think since I have the free version, it's tuning my map on the deceleration also. At idle my AFR's are 16-16.5, which not too concerned with since it has no load on the motor, but cruising, where you have a very slight load on the motor, I'll still seeing 16-16.5 AFR's with about 12-14 inches of vacuum. Is that too lean for cruising? On the freeway, at higher speed with a bit more load on the motor, I'm around 15.2-15.7 or so. I remember talking to Jon once, and he said you can lean it out a bit more for cruising since there is not a big load on the motor.

The moment I get close to 0 vacuum or build any bit of boost, it immediately will go to the appropriate AFR's and stay there throughout the rpm range when doing a pull.

Now the paid for version will allow me to put in perimeters that will stop it from tuning on deceleration, correct?

Should I redo my light load section of my map?

[mx-3_4evr]

I have my idle in the 14-15 A/F, during cruise is 15-16 A/F, and deceleration goes all the way lean as you don't need too much fuel during deceleration.

[Lex]

The target for stoichiometric burn is 14.7 AFR. This creates the least amount of pollutants. You can go leaner and it will run hotter and create more NOx emissions.

I find it that my car doesn't like dipping into the 16s. It starts to miss at that point so I tune for a cruise between 15 and 15.5 as after a sustained cruise some fairly high EGTs are also achieved.

Do you have an EGT gauge to watch?

You should be able to set some boundary conditions for the MAP reading for the autotune feature so that you can avoid taking deceleration values into consideration.

[deadly_sleeper]

Yes, I have an EGT gauge to watch. When I'm cruising on the highway or around at higher rpm, I'm anywhere from 800-900. Usually if it's a light load, I'm around 800 in town. But also, I still have my stock downpipe, so there is a good amount of restriction there.

So my next question, I have the latest tunerstudio and was trying to get back into the auto tune function and I can't find it. I haven't used it in several months so I don't know if they changed it to a different spot or if they just got rid of it in the free version. Does anybody know? I am eventually going to buy the full version, just have other things I need to spend the money on first.

[b-potent]

For cruising i run around 14.7-15.5, for deceleration i use the "overrun settings" to cut fuel during deceleration and i've been able to get some really good gas mileage. Its sort of a sacrifice because if you want a silky smooth tune, crusing should be 13.5-14.0, but im more intersted in gas mileage which is why i run leaner.

[deadly_sleeper]

Ok, found one of my problems. In the new versions of the free TunerStudio, they have locked out the VE Analyzer Live so you can't use the auto tune function at all. I purchased that today and am going to set it up and see if I can't correct some of my problems.

[scortadict]

i'm running around 14.3 to 15 for cruising. if i hit 16 its start to miss. in deceleration i have around 20.

[Lex]

On decel there is no reason to not use the Over run settings completely shutting off the injectors. No popping from the exhaust and you save some fuel. The engine braking is also more effective.

[323driver]

I run around 16 in cruise, I don't have any issues with the spark but that could be different depending on what coils you use.

[deadly_sleeper]

I just have the stock ignition for now. I know at idle with the high AFR's, it was missing. I thought it was my coil or wires, but now I just need to get a better tune on it during vacuum. While in boost, I have the correct safe AFR's.

[Lex]

It also depends on the size of your injectors. If your injectors are larger (550cc+) then you will have a harder time keeping a smooth lean idle/low load because the injectors must open for very short periods of time and the discrepancy in fuel injected from 1 cylinder to the next can vary enough to make a cylinder miss at 17 AFR and another run fine at 15 AFR while the average AFR is 16.

On stock 230cc injectors, it is very easy to maintain a nice stable lean idle.

[deadly_sleeper]

Yes, and I think it's about time I did a free air calibration on it also. It's been over a year since the last one.

[nos92mx3]

Well you also have to remember running that lean at part throttle and cruise you should also advance the ignition timing to compensate.
A leaner afr's flame front in the combustion chamber actually moves slower than a richer one.
Advancing the timing will acutally help with the cruise conditions, you wont get the surging and as much popping through the exhaust

[BoostedTrixx]

Well you also have to remember running that lean at part throttle and cruise you should also advance the ignition timing to compensate.
A leaner afr's flame front in the combustion chamber actually moves slower than a richer one.
Advancing the timing will acutally help with the cruise conditions, you wont get the surging and as much popping through the exhaust

^^^^ Good note to add about flame front speed vs mixture, also do use timing adjustments as noted above to help with cruise conditions, helps also with idle adjustments too, more so then fuel adjustments at idle do.

My idle is a little rich on 460s, around 14.0-14.3. Not too bad but could save some more gas there. Cruise AFRs are 15.0-15.6 around 10-13 inches vac. with EGTs in the 800 range. Thats on a 2.5inch exhaust. Obviously different cars and setups offer different possibilities, but for reference, my buddies EVO 8 was tuned at 16.0-16.3 at cruise (same amount of vac as me).

14.68 being official stoich, just means in basic terms that equal amounts of gas and air were burnt up to leave no leftover mixture of either (extra air or fuel) obviously you can go leaner for better gas mileage and what not...

My autotune on tunerstudio is setup for target AFRs in voltage, idk how yours is but if same, best off to find a voltage chart for AFRs (AEM widebands come with one).

[yunvmyegt]

eric what are you using for overrun settings i never did set mine up either... i know this is old, but im not the one who bumped it...lol...

oh and hes using normal afr values, not volts.... you can go in and change things...