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BL of 105 at 60 MPH

465 Views 5 Replies 3 Participants Last post by  Steve Wood
Somewhere out there in the vast world of TRs is a list of optimal numbers for the various readings pulled from the computers in our cars with scanners such as scanmaster and turbo link. I would like any help from anybody in tracking down this info.
I thought that a BL of 105 was good. But apparently it means something is not right.
I thought an INT of around 128 was good.
But mine jumps from (EST) 109 -130.
Should be steady right or wrong.
As stated earlier.
Any info on an article or whatever with the (This is what it should be numbers) would be appreciated.
Thanks in advance.
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BLM should be close to 128-no more than 10 off in either direction.

Int is a short term correction-pay more attention to the BLM.

Ken Mosher provides an excellent set of instructions online that you may download for Turbolink which discusses many of these issues.


I respect your opinion highly - especially since you are not afraid to say "we've heard of these magical numbers but there is no reason, etc." IE< tps at 4.6 for wot.

For blm - do you look at idle or wot? if both - do you give a higher importance to one or the other?


Then I guess I have to tell you that I am not qualified to fully answer the question.
I use MaxEffort chips that are completely open loop and the blm cells do not apply. Therefore I don't pay too much attention to the blm discussions.

TurboBob, Dave Huinker, Jim Testa, or Todd King can do a far better job at explaining this one.

If you look at a Direct Scan playout, you will see that there is a matrix displaying BLMs and this matrix is composed on 16 cells numbered 0-15. Each one of these cells is designated by an rpm range and maf flow (may actually be load-it gms/sec anyway.

The top left of the matrix would represent an idle condition with minimal load and the bottom right hand corner of the matrix would represent wot and high load.

Some of the cells are hardly ever used because they represent near impossible conditions such as 600 rpm and 255 gm/sec.

The blm we see on ScanMaster or Turbolink represent the number in the cell that is being used at the moment. If at idle, it may be cell 0 or 1. If at brisk acceleration, it might be cell 15 which is the same one used for wot.

In practice the most used cells are the ones that fall adjacent to a line drawn from top left to bottom right thru the matrix.

When we start with a cleared ecm, these cells are blank for a few minutes of driving but the ecm learns what was required under each cell's conditions and stores that fueling information into the matrix so the next time that conditon is encountered the ecm supplies that amount of fuel automatically and looks at the results for further fine tuning.

I don't recall what determines when the learn mode is on and off at the moment.

In theory, I think, we should try to achieve numbers near 128 in all the commonly used cells. Having said that, the chip maker may make that hard to do. Some may try to make the idle cells of 0 & 1 ultra lean to improve turbo spool or some other favorite tweaks.

Cell 15, as it learns during brisk acceleration has some affect on wot fueling. I am not comfortable with trying to explain what happens at wot when the ecm ignores the o2 and acts like an open loop chip because I don't really understand the hand off from closed to open.

I do know that on a lot of the older chips, that when one raised the fuel pressure, the ecm would try to learn the new pressure and therefore reduce the delivery of the extra fuel thru adjusting the blms to keep the number in the 128 range. Then we learned to lock cell 15 so that it would not adjust the fueling and ultimately remove the fuel we tried to add. I don't know if most burners lock the cell or if it is an option.

Again, I don't have to worry about such stuff.

I don't think I have answered your question but I got in some good typing practice. Hopefully one of the chip guys will explain better and offer some solid advice.

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So what would a number of 105 mean?
When warmed up at idle. It's 105.
When cruising at a steady speed... 105.
Does it mean it's lean or what?
What can be done to correct it?
Also. Should the INT. number be a steady number or should it jump around as posted in my opening post?

I do know the chip is not updated to the new parts. I plan on getting that done soon.
May go with a Red Armstrong chip or a J.T.
Heard both of these chip makers are on the up and up.

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It means it is a bit rich and the ecm is pulling fuel out to bring it into line. The INTs jump around more.

Red's chips are notorious for being rich. Give Jimmy a shot but tell him to not correct Zap anymore on Hot Earred Missile tech stuff.

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