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Username Post: New Accel thruster software question        (Topic#194277)
AZDoug 
Member
Posts: 48

Loc: Arizona
Reg: 07-07-06
07-15-08 04:48 PM - Post#1478496    

I have a new Thruster box and harness sitting in a box here in my office.

Loaded the Thruster software to get a feel for itand look around and see what is different compared to my MEFI software.

Thinking I would simply grab a typical calibration off the Accel database supplied,and modify it based on my current MEFI fuel, IAC, spark, etc tables in the comfort of my office using the OFFLINE function, i find that the software will not save any changes except for a X multipier function created change, no manual changes, no bracket up/down changes, no interoplation changes.

I don't want to sit in a 100 degree garage for 6-8 hours learning and programming this, i would like to pre program a calibration so i can load it right into the Thruster ECU after I install it on my vehicle.

Why won't the software record any modifications to a calibration other than the X multpier inputted changes?

I selected a 383 crate motor calibration, and saved it under a different name,and am using that to try and experiment with, but I cannot modify anything in either my renamed copy, or the original file.

How do I get this to record my calibration parameters on my office/laptop computer so i can be up and running in a few minutes once the new ECU is installed in the car?

Or does my officeor laptop computer have to be plugged into the ECU so they can talk to each other once, before the software will let me change and save calibration data?

Thanks,
Doug

 
Bullshark 
Member
Posts: 95
Bullshark
Loc: St. Charles, Mo.
Reg: 06-15-06
07-16-08 07:09 AM - Post#1478823    
    In response to AZDoug

Doug, be sure to hit return after changing an entry followed by a F10 to simulate sending it to the ECU. You should then be able to do a "Save Global Calibration to a File" under the File drop down header.

Bullshark

Edited by Bullshark on 07-16-08 07:10 AM. Reason for edit: No reason given.

 
AZDoug 
Member
Posts: 48

Loc: Arizona
Reg: 07-07-06
07-16-08 12:22 PM - Post#1479033    
    In response to Bullshark

Thanks,

That solved that suituation. I can cahnge stuff now.

Now,a nother question: I powered up the ECU and changed the system and configuration data in the ECU, that went smoothly, and then downloaded the whole ECU program to my computer and saved it.

Now, trying to reprogram everything,

I have all the pulse width table and spark tables from the MEFI that I have programmed on the street and dyno.

The Fuel, and VE table calc estimator gives me funny results.

I have a 427 Chev SB, i have programmed the injector size into the ECU, they are 50# GM high impedence injectors. I have entered all the correct data in the VE table estimator utility, cam closing angle of 44 degrees, .541"lift, 4.190" bore, 3.85" stroke, 8 cylinders, 9.65 CR, 43 PSIG fuel pressure, etc

The VE calc utility gives me a VE table, and the corresponding pulse width utility gives me a pulse width table with pulse widths that are WAY too wide, i.e, I have been running ~6.1 to 6.4 msec pulses on the MEFI at 100% MAP from roughly 1600-5400 RPM, and have from 400-430 lb-ft of RW TQ in that RPM range at about 12.9 AFR, so i know the fuel was OK in the MEFI program.

The VE calculator/pulse width utility says I should be running 10- 11 msec pulse width at 100% MAP, which is way, way too wide. When I manually change the fuel pulse width in the pulse table, then the VE table gives me values of about .5 VE in the 100% MAP range, or about half of what it really is.

What is causing this, and should I just program all my old pulse width table values in and ignore what the VE table says?


Other suggestions?

Thanks,
Doug

 
Bullshark 
Member
Posts: 95
Bullshark
Loc: St. Charles, Mo.
Reg: 06-15-06
07-16-08 01:04 PM - Post#1479055    
    In response to AZDoug

Doug, The VE table numbers from the MEFI do not correlate to the Accel Gen VII. I would do what you suggest and key off the injector pulse width. Send me or post a copy of the Calmap VE table when you are done and maybe we can do a sanity check and compare it to a similar engine's VE table. I have one from a SB 408 that we have run on an engine dyno. This engine had a Holley Stealth intake with 45lb injectors. I still think you will have to do some tweaking on the tune since different algorithms are used.

Bullshark

 
AZDoug 
Member
Posts: 48

Loc: Arizona
Reg: 07-07-06
07-16-08 03:25 PM - Post#1479158    
    In response to Bullshark

This has me stumped.

It will be trial end error.

Accel just sent me some calibrations of various engines by e-mail,and most in my size/HP category show 100% MAP VE of around 90+% and pulse widths of 10-12 msec in the 3000 RPM range at that MAP.

Now why my MEFI fuel pulse width has 6.3 msec pulse widths at the same MAP and RPM, I do not know. I know the motor runs good, it's not like it is way too lean.

I am sure the base MEFI table topography will be an almost exact match for the Thruster base Fuel map/VE topgraphy, I just need to translate MEFI pulse width into Accel pulse width,and use the same ratio everywhere.

I would have thought pulse width in msec was pulse width in msec, no matter what controller is being used, but it would seem this is not so.

I ordered an LC-1 UEGO cable, so at least once I get this set up most of the way, I can just turn the wideband on and let that do the rest.

Thanks,
Doug

 
Bullshark 
Member
Posts: 95
Bullshark
Loc: St. Charles, Mo.
Reg: 06-15-06
07-16-08 07:40 PM - Post#1479367    
    In response to AZDoug

Doug
Are you comparing like fuel injection modes or strategies for firing injectors? i.e. sequential, staggered batch etc. I don't recall how many times injectors are fired per engine cycles by the MEFI Bank to Bank strategy.

I opted to use sequential on my 502 and we also used that on the 408 sb.

Bullshark

Edited by Bullshark on 07-16-08 07:57 PM. Reason for edit: No reason given.

 
AZDoug 
Member
Posts: 48

Loc: Arizona
Reg: 07-07-06
07-16-08 09:57 PM - Post#1479417    
    In response to Bullshark

MEFI fires each bank once, every 720 degrees, 360 degrees apart.

It is not multiple pulse per revolution.

Doug

 
AZDoug 
Member
Posts: 48

Loc: Arizona
Reg: 07-07-06
07-16-08 10:08 PM - Post#1479420    
    In response to AZDoug

I am not sure what to make of the Accel supplied calibrations.

on one hand, they have a 427 SB, 540 HP, 48# injectors with 12 msec, 100%MAP, 3000 RPM pulse width, and another calibration claims 454 BB, 480 HP, 30# injectors, 10 msec, 100% MAP, 3000 RPM pulse width.

Note the diff in claimed injector size.

30# injectors if replaced by 50# injectors on the 454, would need about 6 MSEC pulse width.

Doug

 
Bullshark 
Member
Posts: 95
Bullshark
Loc: St. Charles, Mo.
Reg: 06-15-06
07-17-08 03:40 AM - Post#1479470    
    In response to AZDoug

My experience is that Accel's calibrations are fat. For my RamJet 502, the VE table after some street tunning was ~ .2 lower across the map. The calibrations were supposedly for identical engine setups and injector size with one exception. I am running stock sidepipe exhaust.
It will be interesting to compare the two end results when you are done (MEFI vs Accel). Keep us informed.

Bob

Edited by Bullshark on 07-17-08 03:41 AM. Reason for edit: No reason given.

 
AZDoug 
Member
Posts: 48

Loc: Arizona
Reg: 07-07-06
07-17-08 09:20 AM - Post#1479625    
    In response to Bullshark

It wouldn't surprise me if they are fat calibrations, too rich doesn't burn holes in pistons and keeps the liability down.

I suspect their VE table is not real VE of the engine, but an ersatz table that they ahd to call soemthing, whose final output is pulse width, but it calculates pulse width based on air and water temp correction, injector size (or size change), air density, etc.

The program so far seems more versatile than the MEFI software and perhaps more sophisticated, it is just taking me some time to figure out where evrything is,a nd how to convert from one to the other.

As far as the VE table, I will simply make it have the exact same topography as the fuel pulse width table in the MEFI, and then, if it is too rich, or too lean, I can change the whole table up or down at once using the X multplier function until I get a close A/F ratio at a known cruise condition,and it should be real close to what i have.

Probably be a couple weeks before I do the install, I will post what i find with the pulse width correlation

Thanks,
Doug



 
Bullshark 
Member
Posts: 95
Bullshark
Loc: St. Charles, Mo.
Reg: 06-15-06
07-17-08 10:29 AM - Post#1479658    
    In response to AZDoug

That should be pretty easy to do. Once you get your LC-1, you should be able to drive around in closed loop stabilizing at a few key cell points around the map and just hit autocal radio button on the Base VE screen. That will automatically adjust each of the cells to the proper VE setting based on the corresponding A/F table set point. Then just curve fit the rest of the cells as you point out.

Bullshark

 
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