Chip tuning - non PE mode

[dennisL]

I'm trying to tune the chip to match my car and I could use so help from anyone with experience doing a similar thing. I started with the idle and have that nailed. Smooth as glass!

Next I want to get the BLMs in-line during normal driving. Right now, most indicate lean and 1 or 2 indicate rich. Here's where I am:

I set the Injector Constant for the injectors I'm using (ie, 30lb green-stripe = hex 43). This number matches the flow rate at 45lbs psi (30 lbs/hr). Now here's the dilemma, if my BLMs say the mixture is lean, do I change the MAF tables to report less air or do I change the Inj Constant to add more fuel?

I'm leaning toward changing the MAF tables because they problably should be "tweaked" anyway to reflect K&N filter, solid MAF pipe, 1 screen removed, etc. I just don't know a scientific way to go about it, and I'm tired of guessing. Any help would be appreciated.

 

[TurboDave]

Cruise BLM cells usually always are lower than all the others. Haven't really looked into why, it's just the way it is.

But, if you want to tweak on something it would be best to try the MAF tables, since changing the injector constant would affect fueling "everywhere".

Changing them to report "less" air would reduce the fuel demand and lean it down a little (I hope I have that right).

Just make sure you get good data on where your at when you make the changes. One thing that would help is to set up your DS.ini file to display raw maf data with the b0(zero) parameter on.

Create a DS.INI file and have the following line in it:

0xb0 2 d

those are zeroes on oh's. noice the spaces also.

 

[bruce]

Originally posted by dennisL
I'm leaning toward changing the MAF tables because they problably should be "tweaked" anyway to reflect K&N filter, solid MAF pipe, 1 screen removed, etc. I just don't know a scientific way to go about it, and I'm tired of guessing. Any help would be appreciated.

Piece of cake.
First off you need the right tools. A scanmaster and WB will save you more then there costs in fuel.

Once you change anything in the intake tract the MAP tables and scalers are no longer accurate references for the gm/sec.. BUT, in doing the math, they give you reference points.

Soooo,

The math for the gm/sec is table entry times table scaler, divided by 255.

Just to use numbers that are easy to manage.

Say at 20 MPH you're running 10 gm/sec. You look at Table one and see the scaler is 10, and then in the table the last entry is 255. That would be where the frequency of the MAF correclates to 10 gm/sec. From there depending on if you were rich or lean you'd want to change the reported air flow to change the mixture.

The low speed stuff is fairly forgiving in slight errors, as you get to the larger values things get more critical.

But, having it all right is worth it.

After some playing with it, it gets real easy.

 

[dennisL]

Hey, thanks guys!

Dave, I wasn't aware that DS could be changed to report raw MAF. I'll try it this weekend. Thanks for the tip.

Bruce, I've got Direct Scan but the prices I've seen for a WB are pretty steep. Do you recommend a source?
Thanks though for reinforcing my thinking of leave the fuel alone, and change the air (for low and midrange of course). When I start on PE, I'll let you know.

This might be naive but has anybody figured out, lets say for just MAF table 1 and 2, what the changes should be if all that was done was replace the stock air filter with an open K & N? For the moment, I'm trying to stay focused on idle and non-PE driving.

Oh, one other thing. Do you guys recommend "tweaking" the MAF correction for MAT table? Since airflow is also an index to this table, and we're changing the reported airflow ....

 

[bruce]

Originally posted by dennisL

Bruce, I've got Direct Scan but the prices I've seen for a WB are pretty steep. Do you recommend a source?
Thanks though for reinforcing my thinking of leave the fuel alone, and change the air (for low and midrange of course). When I start on PE, I'll let you know.

This might be naive but has anybody figured out, lets say for just MAF table 1 and 2, what the changes should be if all that was done was replace the stock air filter with an open K & N? For the moment, I'm trying to stay focused on idle and non-PE driving.

Oh, one other thing. Do you guys recommend "tweaking" the MAF correction for MAT table? Since airflow is also an index to this table, and we're changing the reported airflow ....

For a WB, WWW.DIY-WB.COM , costs about $20 for the heater, $35 a nice LED display, and $130 for the sensor. For under 200 you can build your own. There are others but they all start at like $500.

I just grab a stock .bin, hook up direct scan, the WB and start.

Have two chips, one stand by, and then the one you're working on.

On the working one just set the C/L to some rediculous number for the temp enable, and start in. When you're using a WB all that BL stuff is immaterial, and just wastes your time.

Stoic is just a reference, for the emission folks. You might find that your car gets along just fine without it.

The Temp correction stuff for the MAF can be left alone.