SAFC + 2GMAF + 680cc's + LM1 Wideband: Tuning and the right 0/2 voltage?

[turbo95dsm]

Ok, I have installed my LM1 and my 0/2 at idle and low throttle cruise are 14.5 to 15. I'm told that 12.4 is perfect and below 12.4 would be rich where as above 12.4 would be lean. I adjusted my AFC all the way up to +20% for 1k, 2k, and 3k RPM at low throttle. The wideband displayed the 0/2's drop down to 13.9 but then they raised right back up to 14.5 to 15. When i go to like -7% the 0/2's shoot up to 16.2%. At WOT my 0/2's are like 10.1 with an EGT of 800. My EGT's at 3k low throttle cruise are 740 and 500 to 550 for idle.

I know all cars are different but here's my questions:

~ Is there something that the car is doing to stop the fuel from being added? (20% makes no difference?)
~ What should be good 0/2's for idle and low throttle cruising?
~ Am I correct about the lower the number the richer and the higher the leaner?


Thanks

 

[kpt4321]

Whoever told you how to tune is wrong wrong wrong, you're not allowed to listen to them anymore.

At cruise, you want it to be 14.7:1ish. The fuel trims will try to keep it there, which is why you're having trouble changing it. You don't want to use the wideband at cruise, you want to use the fuel trims on the datalogger.

At full throttle, 12.5:1ish is the best A/F ratio for power. However, it's very doubtful that your particular car will make the most power there. Especially on pump gas, you will usually end up down near 11:1 or richer.

Don't just use A/F ratio to tune, use knock/timing as well.

 

[turbo95dsm]

Originally posted by kpt4321
Whoever told you how to tune is wrong wrong wrong, you're not allowed to listen to them anymore.

At cruise, you want it to be 14.7:1ish. The fuel trims will try to keep it there, which is why you're having trouble changing it. You don't want to use the wideband at cruise, you want to use the fuel trims on the datalogger.

At full throttle, 12.5:1ish is the best A/F ratio for power. However, it's very doubtful that your particular car will make the most power there. Especially on pump gas, you will usually end up down near 11:1 or richer.

Don't just use A/F ratio to tune, use knock/timing as well.

Ok so basically the LM1 should only be used to tune at WOT with will put the car into open loop and the ECU wont check the stock 02?


Thanks.

 

[kpt4321]

That is correct.

 

[turbo95dsm]

Originally posted by kpt4321
That is correct.

Ok, last question. Is there a point at low throttle that the car will enter open loop? Lets say 4k rpm at 10% throttle or something like that?

Basically is there an RPM I should start tuning the SAFC for low throttle or should it be left alone all the way to 6k?


Thanks.

 

[kpt4321]

Originally posted by turbo95dsm
Ok, last question. Is there a point at low throttle that the car will enter open loop? Lets say 4k rpm at 10% throttle or something like that?

Basically is there an RPM I should start tuning the SAFC for low throttle or should it be left alone all the way to 6k?

I think you are a little bit confused. You want to tune the SAFC at low throttle too, you just don't want to use the wideband to do it. You want to use the datalogger, and try to get the fuel trims as close to 100% (1g) or 0% (2g) as you can.

Then use the Wideband and the logger and full throttle.

The car will switch into open loop a little bit above 4k rpm, or around 50% throttle. Maybe 60%. I can check that out to be exact later.

 

[chaye]

so, will 12 to 1 apply when using dsmlink
i just started tunning for regular driving. My first log was around 19 to 1 wich was too lean cause i was getting bout 3 degrees of knock
i did some tuning, added some fuel at certain rpms and got down to about 16 to 1 on the a/f readings from my DSMLINK
thanks guys

 

[turbo95dsm]

Originally posted by chaye
so, will 12 to 1 apply when using dsmlink
i just started tunning for regular driving. My first log was around 19 to 1 wich was too lean cause i was getting bout 3 degrees of knock
i did some tuning, added some fuel at certain rpms and got down to about 16 to 1 on the a/f readings from my DSMLINK
thanks guys

Crazy. My AFR's are 10.1 to 10.9 under full throttle. Have you done anything or is your car bone stock?

 

[kpt4321]

Originally posted by chaye
so, will 12 to 1 apply when using dsmlink
i just started tunning for regular driving. My first log was around 19 to 1 wich was too lean cause i was getting bout 3 degrees of knock
i did some tuning, added some fuel at certain rpms and got down to about 16 to 1 on the a/f readings from my DSMLINK
thanks guys

Your A/F ratios are NOT 19:1 or 16:1 at full boost, it's just not possible. The car would either explode, or more likely, not run.