How BLM's affect drivability?

[MNwe4]

Ok, so I think I have a good grasp on the BLM thing and when the computer is adding or pulling fuel. Question is, if the A/F looks good (cruising and idle) and the car is running fine, does it really matter where the BLM's are?

Example: Car was tuned with Translator BASE at 4 (10% rich @ idle), so it is running good, A/F is good, and performs well under WOT. However, the BLM's at idle are 106.

Now switch Translator BASE to 3 (std. setting) and let the computer re-learn. Car still drives good, but from what I understand, switching to BASE 3 will change the fuel curve, even under WOT, which I'd like to avoid. Now the BLM's at idle are 123, which is in the ball park.

Any thoughts on which setting to go with? How will the low BLM on BASE 4 affect the car?


P.S. - Eric if you are reading, this is not your chip that I just purchased. I'm playing with my old computer/chip combo just to have fun and try and learn some stuff. Your's will be back in shortly

 

[TurboDave]

I forgot to ask you in your other thread what chip has yielded these numbers.

the 105 number isn't terrible although it's further outside the norm than I like to see. Normally anything from 118 to 138 is considered good.

The 123 number is much better. How much has the fuel curve changed at WOT with the idle BLM at 123?

Long story short, unless you're running an extender chip, the WOT switch (which you had set at 8) is going to have little to no affect anyway.

 

[MNwe4]

Thanks for the great responses! To keep it simple, this chip I'm talking about now is a custom 512mb with 28pins I believe. So it has an adapter and was burned at a local performance shop a while back.

I haven't had a chance to make any full passes with the BASE at 3. I punched it a few times from 60mph and took it up to 75-80mph and it still responded well, but I assume you can't really gather good data from that short of a run. Being basically in Minneapolis, you have to drive a long way to get out to some country roads to make some good pulls.

I'll load the idle PL files when I get home from work if any more info can be gained from them. This is my first time ever tuning the car myself and I REALLY appreciate all the help I have received from various board members.

Thanks again, Dave

 

[MNwe4]

Ok, here are the PL files if anyone's curious. Also, I know to take recordings at idle and WOT, but are there other times that recording would be beneficial? Maybe a highway cruise at 60 or rolling from a stop sign up to 40 mph? Just thinking if any good info could be gained from that.