Hey,

Some of you - I am sure - have seen my plethora of threads trying to fix my extremely split, and extremely ****ed BLM's. Apparently a 108LSA and .600 Lift just don't jive well with the oxygen sensors under normal idle and cruise RPM's.

After consulting several professional tuners, the general consensus is that with this cam and my current set up - I need to just run an Open Loop Tune.

I have zero experience with this.

I know I need to set my Coolant Temp for Closed Loop cut in to 150* C. but ...

What tables adjust AFR in Open Loop?

I can run Open Loop and still use my MAF right? It just omits any BLM's ... ... ?

I have a wide band and plan to use it to keep an eye on my AFR.

I did a search. It is overwhelming with conflicting information. If you don't know what tables are accessed for fueling in OPEN LOOP (as in, you have never made an OPEN LOOP ONLY tune) please do not guess, say what others "say" is used, etc. It's rediculous after searching 100+ threads that I have found no concrete information on this





Thanks all,

Joe

 

Right ... guess everyone is sick of me posting in the Computer Forums ...

Long story short - I am taking a stab at it on my own since there are so many conflicting opinions.

Basically - I am dailing in the Open Loop AFR Table to 14.0 then scaling my MAF Tables til it matches for all given RPM's/Loads based off my wideband. Once these #'s are in agreement - I will then crank my Open Loop AFR Table down to around 13.0-13.2 in the normal operated temperatures and 90-100kPa range and see how she looks on my wideband at WOT.

I am hoping that IF the MAF tables are calibrated correctly, the Open Loop AFR Table will correlate nicely and show very similar numbers to my Wideband.

I am doing NOTHING with:

% Change A/F vs. RPM @ WOT
% Change A/F vs. Coolant Temp

From what I have read, MORE people have had these tables do NOTHING for an Open Loop Only tune than the people that have. Of the people that have, oddly, I noticed several were "achieving" open loop by Unplugging the O2's rather than setting the Min. Coolant Temp for Closed Loop from 32.75*C to 151*C. Maybe this is why some have luck with the two % Change tables while others don't.

Either way, after (2) nights of searching the boards and Google, and having no solid evidence - I went with my best judgement. If it doesn't work - I have a wideband that will tell the rest of the story and point me to the % Change tables.

Hopefully this information can help others as it oddly, is difficult to find any information on doing an Open Loop only tune. Which is weird because there are enough idiots out there with the Bigger = Better mentality. I would have thought more guys would have HUGE cams that can't be accurately accommodated for via Narrowband O2's.

Weather is dick right now but hopefully by the weekend I can run her and post back on here.

Later,


Joe