How do chips work?
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Joined: Jan 2000
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From: Lima Oh
How do chips work?
Ok so I know how the computers work with BLM and INT values and all but I can't figure out how "chips" or reprogrammers work. Does the reprogramming input new blm and int values into the computer? Or does it modify the outputs of the computer with it's own values. I.E. does it intercept the outputs to the injectors and distributor and feed out it's own values or does it modify the ecm's internal values? If that's what happens how does the computer deal with feedback that would be the result of the chip and are not what it commands-richer or leaner a/f than commanded? If the chip inserts new blm values in to the ecm what prevents it from relearning the values it originaly stored? It got them because they are what worked best for the engine.I can't imagine the intergrator is disabled. So what's the deal? Help me comprehend!
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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter
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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter
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Joined: Dec 2000
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From: Southern California
Hi,
The chip contains run-time code, which is the instruction set for the processor, and lookup tables. Generally we do not alter the run-time code, only the lookup tables. The lookup tables contain all the fueling, EGR, spark, BLM and INT min's and max's, etc. HTH's
-Carl
The chip contains run-time code, which is the instruction set for the processor, and lookup tables. Generally we do not alter the run-time code, only the lookup tables. The lookup tables contain all the fueling, EGR, spark, BLM and INT min's and max's, etc. HTH's
-Carl
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From: Lima Oh
I understand how you can change the lookup tables but what keeps the computer from relearning the values it had previously stored? Or do you lock in the table values to a limited min and max? Or does the computer not see a need to change these values? Also how come the computer won't "learn" the best way to operate the engine after a big upgrade(cam,heads...). Is it because the computer sees a need for a change that is to great? i.e. a few microseconds injector pulse width increase out of the blue?
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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter
------------------
82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi, manly b&m megashifter
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Joined: Jul 1999
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From: The Bone Yard
Car: Death Mobile
Engine: 666 c.i.
Because you have completely changed the air flow characteristics along with the Volumetric Efficieny over the power band.
MAF will help to a point, but if you increase the air flow by 50% (and haven't exceeded the 256 gm/sec constraint), you'll have to change your injectors to get the proper amount of fuel. Then let the PROM know or it will have the incorrect pulse width to fire the injectors at a given time.
MAF will help to a point, but if you increase the air flow by 50% (and haven't exceeded the 256 gm/sec constraint), you'll have to change your injectors to get the proper amount of fuel. Then let the PROM know or it will have the incorrect pulse width to fire the injectors at a given time.
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Joined: Jun 2000
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Originally posted by 82z:
I understand how you can change the lookup tables but what keeps the computer from relearning the values it had previously stored?
Just say you richen the VE for fuel x%. The ecm in closed loop will try to correct that so it will be 14.7. There is only a limited amount a ecm can correct before a code for rich or lean sets.
Or do you lock in the table values to a limited min and max?
There are limits to the BL, and Int range.
Or does the computer not see a need to change these values? Also how come the computer won't "learn" the best way to operate the engine after a big upgrade(cam,heads...). Is it because the computer sees a need for a change that is to great?
Computers have no sense of drivibility. The lasted PCMs, have some clever learning ability.
I understand how you can change the lookup tables but what keeps the computer from relearning the values it had previously stored?
Just say you richen the VE for fuel x%. The ecm in closed loop will try to correct that so it will be 14.7. There is only a limited amount a ecm can correct before a code for rich or lean sets.
Or do you lock in the table values to a limited min and max?
There are limits to the BL, and Int range.
Or does the computer not see a need to change these values? Also how come the computer won't "learn" the best way to operate the engine after a big upgrade(cam,heads...). Is it because the computer sees a need for a change that is to great?
Computers have no sense of drivibility. The lasted PCMs, have some clever learning ability.
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