BPC question. Can you check my math? 7060 $85

[chevmasta]

Sooooo,

After reading some more about TBI tuning my 7060 $85 PCM 454 93' K3500, I realized I haven't probably set it up exactly how I should. It runs good but still needs tweaking. So I'm starting over.

Can you check my BPC math please?
From davew's calculator I checked the BPC for the stock truck.......his calculator says 134. MY OEM BANC.bin has 142. thoughts? This is for 80lb injectors.

Only mods the truck has is a set of JBA headers and a 3" exhaust with a fuel pressure increase to 16lbs.

Using this formula: NewFlow = OldFlow * (SqRt(NewPsi / OldPsi))
I get 92lb injectors.

Plug that into davew's calculator spreadsheet and I get 119 BPC value.

So would you suggest one of the very first things I change in the .bin is put the BPC at this 119 value?

Thanks,
Ryan

[EagleMark]

BPC or in other masks BPW is 134 for 74lb injectors and 140 for 80lb injectors.

I get 92.38 and BPC of 120.41 so now we are splitting hairs, but yes 119 would be the first thing to do in bin file.

Before retuning off BLM/LTFT disconnect power to PCM to loose the BLM learn and let it relearn.

[chevmasta]

Thanks Eagle,

Can you give me a sanity check for initial parameters to change? Here's what I believe I should start out with:

Initial advance: 4* (set to match dist)
WOT delay: zero'd
Base Pulse Width Constant: 120 (calculated above)
Min Coolant temp to Enable EGR: set to max value
Fuel Cut Off Engine Speed: 4200 (max oil pressure it 35psi hot. I never go over 3600 or so in this truck anyway)
Fuel Resume Speed: 4100
Max spark Advance: 42*
EGR Flag: unchecked
ERR 32 Flag: Unchecked
Power Enrichment Spark Table: zero'd
EGR Spark Advance Correction Table: zero'd

Are there any other item's that you would recommend I start out changing first thing? Before I start tuning VE and Spark Advance tables?

I have the G3 selector with the EX switch so I can have 16 maps. I currently have a map for towing, and for high idle (runs my winch).

Help is appreciated,

Ryan

[EagleMark]

Looks sane.

Usually no reason to change MAX spark.

I have 2 EGR Flags, neither turns it off, both change how EGR works, so look at that one.

Smoothing the VE table makes it easier to start adjusting IMO...

http://www.gearhead-efi.com/Fuel-Inj...Information-85

HTH!

[chevmasta]

I think I misspoke. I went and looked at my BANC.bin and it had max spark at 41.84*. But the spark table has many 45* cells.

I'll just change those cells to match the maximum spark value.

Ryan

[EagleMark]

41.84 is where it's supposed to be. 45.00 in max decell minus the Intial spark advance 3.87 = 41.13

Normally you should leave all the decell spark advance alone, especailly when they are that high, you don't know what Decel, or DFCO spark adders or subtractors are going to do. This mask is not complete, but by the looks of those decel spark advance numbers I'd say there is none. From left to right about half the table and bottom to top about half the table as long as it does not interfere with your acceleration and cruise spark areas.

Hmmm... BANC is an Export bin! May be open loop? Lots of exports are OL leaded fuel. Did it come with the truck? Here in US?

[chevmasta]

Do you know if this PCM has a parameter to set the "target" or "desired" AFR for WA state 10% ethanol Fuel?
14.13 vs 14.7?

All I see is OPEN Loop parameters in the .xdf? I ASSUME this would be a closed loop parameter?

[EagleMark]

It was not there? I added it...

[chevmasta]

41.84 is where it's supposed to be. 45.00 in max decell minus the Intial spark advance 3.87 = 41.13

Normally you should leave all the decell spark advance alone, especailly when they are that high, you don't know what Decel, or DFCO spark adders or subtractors are going to do. This mask is not complete, but by the looks of those decel spark advance numbers I'd say there is none. From left to right about half the table and bottom to top about half the table as long as it does not interfere with your acceleration and cruise spark areas.

Hmmm... BANC is an Export bin! May be open loop? Lots of exports are OL leaded fuel. Did it come with the truck? Here in US?

Yeah I found this out the hard way. in the 1000, 1200, 1600 rpm cells and the 30 and 35kp areas I had pulled out some timing to help decel. Well, at very light cruise (25-35mph) on certain situations I found myself in those cells with my decreased timing. So I bumped them back up the the BANC levels.

I'm pretty confident this truck was purchased at Hall Chevrolet in Prosser, Wa. It was a farm truck with a very large sprayer in the bed for 77k miles. My dad had the truck prior to me getting it with 202k miles 5 years ago. It has 216k on it now. Original engine. 3rd Transmission (hopefully last. 40k GVW cooler, transgo shift kit and some of my sweet ass tuning) LOL!
Build date is 02/93
3.73 gears
SRW

I'm pretty confident nothing has ever changed with the truck as far as the PCM or Memcal is concerned. Just me fooling with it is the only time.

How did you know BANC is an export bin?

[chevmasta]

AWESOME!

Thanks for adding that EagleMark!

the .xdf I had been using was called $85sort.xdf
I'm not sure where I got it from (I think on here though) when we were going thru all that stuff about the two different masks.....???

Tomorrow is playtime! Gonna go tweak my VE table for awhile! :)

[EagleMark]

BCC Find says it has With NM8 EMISSION SYSTEM, LEADED FUEL

http://www.gearhead-efi.com/BCCFind/...shtml?BCC=banc

As long as it's going closed loop, BLM Learn your fine.

[EagleMark]

There's a spreadsheet in the $85 thread Dave made for me when I was tuning one of these and I did some work on the ADX and added a history table for BLM.

[chevmasta]

Yeah it's going in closed loop BLM learn.

Hopefully in a couple weeks I'll be installing my LC-1 to refine the tune even more. For now the stock narrow band will have to do. I also plan on adding a 3 wire AFS74 O2 at the same time.

[chevmasta]

There's a spreadsheet in the $85 thread Dave made for me when I was tuning one of these and I did some work on the ADX and added a history table for BLM.

uhhh, you're starting to talk over my head! LOL
Did you mean you added a history table for BLM in the adx?

I have the link to the $85 thread and the VE correction table in excell.....but I have ZERO idea how to use it. Is there a link to a thread that explains how to use a VE correction table?

edit:
I think I found something on this....I found the "history table" button in tunerpro.....
....this could get moAr fun...(I'm still learning!)

[chevmasta]

Had a good day tuning. Figured out the VE spreadsheet. What I found was even though my fuel pressure has been increased.......I was globally lean starting over with the stock VE table and a BPWC of 120. I had values of over 100% in the table.

After tweaking a few times using the spreadsheet......I went back to the stock BPC settings of 142 and uploaded my old VE table. I typically see 127-132 on the BLM's.

I was wondering how the JBA headers I put on it were gonna effect the VE and it really doesn't look like it much. I, however, don't hot rod this thing. :lol:

This is how my VE and Spark tables look:
BTW, I only post this because I cannot mind much info/help on how other people have their 454's tuned to...and I really don't know if I'm doing this stuff right. haha












Here's the stock spark map from the BANC.bin