all you programmers how hard would it be to do this? sure theres the $58 code, but i had no luck getting that to run on my car, $8D runs great except for the fmu and boost, is it really that hard to add code for a 2 bar map and a fuel multiplier table? and to increase the spark advance table?

 

I'm kind of curious as well. How would it work? 2D lookup table of MAP vs PW multiplier? Or maybe alter the PE desired AFR?

but then... I guess you'd have problems when you're not in PE.

 

There have been afew post in the past about 2bar 8D code But I think everone just used the $58 code.........

/N.

 

Could it be as simple as
1) stating your engine displacement is 2 times bigger displacement (or injectors are half as small).
2) Fixing something for baro check (disable adapt) (and anything else that might get screwed up).
3) Changing the XDF for the MAP multiplier for EVERYTHING (like DFCO, dMAP transients, etc...)
4) Changing the XDF for the VE to SHOW double VE (but not really in the code - where 255 = 100 still internally, but show 255 = 200 in the display).
5) Squeeze your VE into the 0-101 kPa of the new table, and extend it out to 200 in a similar fashion.
6) Squeeze the Spark advance table into the 0-101 kPa of the new table, and of course extend some new numbers out to the boost area.
7) Install 2 bar MAP sensor.

Any other catches???

 

RednGold hit on some of the "larger" issues. There's also the issue with transplanting the WG logic (if desired). The $8D mask (like just about all masks) is tight on RAM. So, just moving it over as-is takes some manipulation....

Based on some suggestions on this board and others, I started looking at the Turbo Grand Prix mask $8F. This ran in a 7727 ECM. I know the WG logic is identical to the $58 logic. Unfortunately, I haven't spent much time deciphering the tables/calibrations to get further. But, that might be a reasonable path to consider for your application....???

 

The 8F is about the most overly complex code GM's done. It's really no better then the 58, and is suffers from some of the problems of the 58. The boost multiplier way of accounting for adding fuel, is so primitive, as to almost be laughable. It really needs to be made into a 3D table.

What one might do is look at how the 58 code accounts for different MAP, and then patch that into the 8D code, if anyone looks at the 60 code floating around, you can see how to *stretch* it into a larger PROM, and then have all the room in the world for adding code. But first someone needs to work out source code for the 8D, and maybe first strip out the unesessary stuff first.

 

Let me throw out some things for informative reasons:
1.) MAP sensor voltage (As my brain sees it) doesn't change the way the ecm operates. Only the range of scaling to engineering units. What if there were "just" a multiplier factor installed for the VE table and then you could tweak the range up/down of the whole thing? Voltage to pressure is preset in the sensor so the appropriate table range scaling could be implemented.
That would let you run the std tables but they would output more fuel for the values.
1a) Does the MAP ever need to go negative to indicate decell?
Wondering if boost is "always" present.
2.) Boost to spark is the part I'm really unsure of. Do you need to reduce spark as the boost rises?
Maybe doing something as dumb as GM did and using a boost multiplier (fractional) to reduce the spark table output value. This would be after interpolation of the tabled value. Or as stated above use a factor on the injector constant.
3.) WG control. Is this a PWM control or direct solenoid/relay ?
Is it a normally "dumping" device?
Engaged to increase or to reduce boost pressure?
1981TTA, Do you have any snippets for that control that you could send me?
I have 8F but don't want to try and figure it out.
Even a text description of the desired operation would be nice, never worked with one before. Could just come up with a complete control code as we want it to be and then plunk it into the finshed product. Might be easier.
Would have to run in one of the slower loops if it gets to big though.
Does it need to be run at spark/fuel speed ?

If this is to go forward I don't see any way of maintaining the AIR, CCP, EGR stuff. That will just add unneeded complexity.
Just fuel, spark / w knock, MAP, TPS, VSS, IAT, CTS, (BARO ?)

Been wanting to remove all the emmisions code anyway.

 

MAP = Manifold Absolute Pressure.
0 = absolute vaccum.......
No there are no negative numbers in dealing with MAPs.

Yes, you do.
There's a HUGE difference from a 2D to 3D table to compensate for it. It's well worth the time to use a 3D.
BTDT

 

I've toyed with the idea of just wiring up a second 2/3 bar map sensor to a 730 and adding the boost code needed and a bit select. That way most if not all of the non boost stuff will work. Might need to add a few MAP quals. Been a while since I looked at the Emissions code. Not sure if this would save anything from a tuning aspect since the VE change from the blower/turbo drag will skew the NA tables you started out with. Been a while since I looked at the $60, but the 3d spark would make things much easier.

 

2 & 3 bar sensors go all the way to full vacuum?
I was under the impression they started at atmoshphere and went only positive psi.
I guess to restate that question, Do boosted systems cross back over the boost boundary back into pulling vacuum that often?
Seems to me the fuel and spark handling "should" be handled differently.
Maybe I'm just making more out of the transitions between PSI and VAC than I should be. If the table is setup to handle both ends of the scale it really shouldn't matter.

Hi Z' , its been a while

 

approximately.....
1 bar 0-5v = 0-100 kpa
2 bar 0-5v = 0-200 kpa
3 bar 0-5v = 0-300 kpa

0 kpa is still perfect vacuum with these sensors. Not all sensors work this way and can cause confusion if you are thinking of them instead. btdt...

So 2.5v can equal 50 or 100 or 150 kpa depending on the sensor.
Or 1v can be 20/40/60 kpa.

Back to the grindstone.....

 

I'd think the EGR code could be re-written to handle a wastegate or boost controller. Most SC guys don't use one (a wastegate or other boost control), though, right? (but maybe now they could use a boost controller - like use a better supercharger with high boost pulley, but reduce the boost at low RPMs as necessary, rather than messing with pulleys and impeller designs).

A 2 MAP sensor system would be really cool. Gets full resolution and drivability with the 1 bar MAP, and gets full boost control with the 2 or 3 or 4 or 5 bar MAP sensor. Not sure if the 730 hardware could support another sensor though.

What are the priorities for this (in no particular order)?
1) FMU Support (injector flow rate vs BOOST (relative to BARO)) - An FMU lets you use smaller injectors.
2) Wastegate or other boost control (based on RPM, TPS, and VSS??)
3) Maintain most $8D functionality
4) Closed loop and PE qualifiers modified to prevent lean boost
Any others??