Who here tunes without a WB O2?

[ChiGGz]

I wanna tune my car so badly with my DSMLink, but I hear people saying that I shouldn't without a WB 02 or at the very least an EGT (both of which I don't have)

Can I rely on the Rear O2 voltage to do ballpark tuning?
What should I be watching out for on the DSMLink?

 

[Coup D E'Tat]

No, you do not tune off of rear O2. Tune for no knock.

I've never touched a wideband - it's a great tool, but isn't neccessary at all.

 

[ChiGGz]

Which brings me to my next question, if I'm not knocking, should I really be worrying that much about a/f ratio and EGT?

 

[keymaster]

If you're not knocking, you have no worries. The common procedure is lean it out little by little until you start to knock, then richen it until the knock goes away. Then you can add timing a degree at a time until knock, then take it back a degree or two.

 

[ChiGGz]

How about when I'm tuning my LTFT mid and lo values...instead of running the car, can I just park it in neutral and keep the car revved at say 2.5 k with the fan on the whole time? Or would there have to be an actual load on the engine? I don't hit boost until 3.8k anyways

 

[SolidBoostTSi]

If you have a datalogger, Do a 3rd gear pull from 2K log it and see where your O2, injector duty cycles, Timing, and fuel trims are. Like ^^^ said, tune for no knock (start rich) then lean it out until you have little to no knock at all. Usually you want your IDC's at about 80-90% and 02 values close to factory spec after all your tuning is done. An engine makes the most horse power right at the edge of detonation.




Solid

 

[ChiGGz]

If you have a datalogger, Do a 3rd gear pull from 2K log it and see where your O2, injector duty cycles, Timing, and fuel trims are. Like ^^^ said, tune for no knock (start rich) then lean it out until you have little to no knock at all. Usually you want your IDC's at about 80-90% and 02 values close to factory spec after all your tuning is done. An engine makes the most horse power right at the edge of detonation.




Solid

I know its been discussed in seperate threads, but to consolidate it into one, what are the values i should be watching for?

O2 below 1v?
IDC ~80-90%
Timing @ idle 5-15
@ WOT 20-30?

 

[FORMONTOYA]

How about when I'm tuning my LTFT mid and lo values...instead of running the car, can I just park it in neutral and keep the car revved at say 2.5 k with the fan on the whole time? Or would there have to be an actual load on the engine? I don't hit boost until 3.8k anyways

the first thing you should do is the base settings...get ltft lo/mid correct (you should do it as stated...up to operating temp then cruise for 10-15 minutes, then idle for 5-10 minutes so you have stable readings), dead time and global are just ballpark and probably will need a little tweaking. then just tune for no knock as stated. if you want to run closer to the ragged edge, then go pick up a wb and possably a gm maft.

jim