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Re: tuning questions

Subject: Re: tuning questions
by djxib on 2013/5/15 16:45:50

Quote:

bam wrote:
Quote:

djxib wrote:

Great question. I did it initially so I could get a true read on the AFR at idle and part throttle cruise (i.e. without the ECM screwing with BLMs). However, when I started testing I realized that the driveability was so much better so I decided to keep it permanent.

Do you mean the BLM's were all over the place so you could not get a clear reading on actual A/F as a basis to start changing the VE table?
How did you set the prom to stay in OL move the temp up where CL kicks in so that the 02's would never come on?
Your wide band 02 is in only one side right? Or do you have two wide band 02's one in each bank of the exhaust, if not then how do you tune the "other" side? Or do you just figure it's not really a problem having one fueling for both banks?
How exactly do you tune your car in constant OL? Do you take the readings of your wide band combined with rpm, KPa data from data master and use that to adjust for lean/rich conditions? How do you know how much to adjust the VE numbers if your data comes from the WB 02?

Great Questions.

From memory (I'd have to check in the tune) I simply changed the block learn enable threshold to a coolant temperature of 300 degrees or something - so it never gets enabled. I might be getting the terms wrong I can check on my tuning laptop at the weekend.

WBO2 only on one side. I assumed it would be fine for initial tuning, I may add another in the future. Even with Block Learn disabled you will still see the millivolt output from the other O2 so you can crudely correlate what the WBO2 is saying and what the stock O2 sensor is saying. (For the stock sensor it's a little inaccurate but pegged above 900mv is definitely rich, pegged close to 100mv is definitely lean - you can draw your own conclusions).

In terms of adjustment of the VE tables (or % fueling) you still use RPM/KPa in the log. If you are datalogging the wideband you need to work out the percentages. So for example if you see 10:1 on the wideband you have 1 part fuel for 10 parts air. You need to get to 14.7:1 (1 part fuel for 14.7 parts air). Fractional math needed which isnt my strong point so I built a spreadsheet for it. If you are not datalogging the wideband just use the stock O2 millivolts as your guide. Not an exact science but you'll feel it (and smell it) if you are on the wrong track.

Hope this helps!

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