[b]tuneing Help[/b]
Thread Starter
Teching In
Joined: Dec 2004
Posts: 8
Likes: 0
From: Orange County N.Y
[b]tuneing Help[/b] TUNEING HELP
HI GUYS
I am new to the site and need some help. I want to tune my own car (03 ZO6) unfortunatly I have no clue about computer tuning. I am a street guy from the 60's so I am at home with four bbl carbs, duel point dist, and lumpy cams but computers I am at a loss. That being said how do I learn to do this stuff, from books or what? If from books maybe someone can recommend some HELP an oldguy out here THANKS
HI GUYS
I am new to the site and need some help. I want to tune my own car (03 ZO6) unfortunatly I have no clue about computer tuning. I am a street guy from the 60's so I am at home with four bbl carbs, duel point dist, and lumpy cams but computers I am at a loss. That being said how do I learn to do this stuff, from books or what? If from books maybe someone can recommend some HELP an oldguy out here THANKS
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
Well to start you wanna get yourself familiar with how EFI works ...
Corvette Fuel Injection and Electronic Engine Control
http://www.amazon.com/exec/obidos/tg...glance&s=books
Excellent book... Good read too
Chris Endre's book Chevy LS1/LS6 performance is good too but not much on the PCM portion, the Corvette book above deals just with how EFI works, closed loop, open loop, what sensors do what etc...
Also http://www.hptuners.com/ if you go to the Products page you can download the manual for HP Tuners PCM tuning software... it describes all the tables, good read
This forum also contains alot of very useful info about VE (volumetric Efficiency) tuning, IFR (Injector Flow Rate) scaling, PE (performance Enrichment) adjustments, setting the MAF (Mass Air Flow Sensor) tables, etc...
Basic rundown of EFI on our cars
Air enters at the MAF , the mass of the air entering is measured and the air Temperature of the intake charge is measured.
the MAF measures the amount of air using resistors, it maintains a constant temperature of the resistor, the more air that passes through the more electricity is required to keep the resistors at that temperature
Once in the Intake Manifold the MAP (Manifold Absolute Pressure Sensor) can also measure the pressure in the intake manifold.
The PCM looks up to see how much fuel to add, it opens the injectors for xx millisecond pulses spraying fuel in with the air. The oxygen sensors (pre Cat) then measure the Air Fuel Ratio... the oxygen sensors on our cars are Narrowband O2 sensors
Narrowband = Very accurate at 14.7:1 AFR, but much less accurate before or after that AFR
Wideband = Very accurate from 10:1 to 20:1
The PCM uses the measured AFR to determine if you're running rich or lean, the short term fuel trims are constantly being updated, these in turn update the long term fuel trims ... these trims (long term) are used to determine how much of a correction is needed to maintain 14.7:1 AFR.
Now this is just for part throttle driving
At WOT the car does not use the Oxygen sensors, and relies on the data it receives for how much air is entering the engine, and then uses the Performance Enrichment table to richen the fuel mixture up... this is how at WOT you can get 12.8:1 but at partial throttle you should be at a constant 14.7:1
There's obviously alot more to it, but that describes the basic sensors (timing is also modified based on several parameters, coolant temp, incoming air temp, etc... )
the HP Tuners forums also contain alot of good info.
But I think that corvette book I mentioned is a good read for anyone... contains alot of useful stuff for people new to the tuning world (not so much how to tune, but as mentioned, it describes how all the sensors work together) Once you know how this all works then you can start to understand what the various tables in the PCM do and what making changes to them does.
Corvette Fuel Injection and Electronic Engine Control
http://www.amazon.com/exec/obidos/tg...glance&s=books
Excellent book... Good read too
Chris Endre's book Chevy LS1/LS6 performance is good too but not much on the PCM portion, the Corvette book above deals just with how EFI works, closed loop, open loop, what sensors do what etc...
Also http://www.hptuners.com/ if you go to the Products page you can download the manual for HP Tuners PCM tuning software... it describes all the tables, good read
This forum also contains alot of very useful info about VE (volumetric Efficiency) tuning, IFR (Injector Flow Rate) scaling, PE (performance Enrichment) adjustments, setting the MAF (Mass Air Flow Sensor) tables, etc...
Basic rundown of EFI on our cars
Air enters at the MAF , the mass of the air entering is measured and the air Temperature of the intake charge is measured.
the MAF measures the amount of air using resistors, it maintains a constant temperature of the resistor, the more air that passes through the more electricity is required to keep the resistors at that temperature
Once in the Intake Manifold the MAP (Manifold Absolute Pressure Sensor) can also measure the pressure in the intake manifold.
The PCM looks up to see how much fuel to add, it opens the injectors for xx millisecond pulses spraying fuel in with the air. The oxygen sensors (pre Cat) then measure the Air Fuel Ratio... the oxygen sensors on our cars are Narrowband O2 sensors
Narrowband = Very accurate at 14.7:1 AFR, but much less accurate before or after that AFR
Wideband = Very accurate from 10:1 to 20:1
The PCM uses the measured AFR to determine if you're running rich or lean, the short term fuel trims are constantly being updated, these in turn update the long term fuel trims ... these trims (long term) are used to determine how much of a correction is needed to maintain 14.7:1 AFR.
Now this is just for part throttle driving
At WOT the car does not use the Oxygen sensors, and relies on the data it receives for how much air is entering the engine, and then uses the Performance Enrichment table to richen the fuel mixture up... this is how at WOT you can get 12.8:1 but at partial throttle you should be at a constant 14.7:1
There's obviously alot more to it, but that describes the basic sensors (timing is also modified based on several parameters, coolant temp, incoming air temp, etc... )
the HP Tuners forums also contain alot of good info.
But I think that corvette book I mentioned is a good read for anyone... contains alot of useful stuff for people new to the tuning world (not so much how to tune, but as mentioned, it describes how all the sensors work together) Once you know how this all works then you can start to understand what the various tables in the PCM do and what making changes to them does.
Last edited by horist; Dec 18, 2004 at 05:41 PM.
Thread Starter
Teching In
Joined: Dec 2004
Posts: 8
Likes: 0
From: Orange County N.Y
Thanks for the info HORIST I will order both books in the morning. Went to HPTuners and poked around and yes that site is loaded with info my head is spinning but most of it seamed to be quite logical it's just a lot to absorb and retain I guess I will just have to get the HPTuner and take one step at a time . Hands on was always my best teacher thanks again
PS corvette fuel injection & electronic engine control is for 1982-2001 will that be ok for my 2003 ZO6
PS corvette fuel injection & electronic engine control is for 1982-2001 will that be ok for my 2003 ZO6
Last edited by OLDGUY2; Dec 18, 2004 at 10:36 PM.
Originally Posted by OLDGUY2
PS corvette fuel injection & electronic engine control is for 1982-2001 will that be ok for my 2003 ZO6
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
^^^ yup you'll be ok... the book even applies to F-Bodies 
The book is an excellent GM EFI book... describes the sensors and how the PCM uses the sensors. Excellent Gen III GM EFI book
The book is an excellent GM EFI book... describes the sensors and how the PCM uses the sensors. Excellent Gen III GM EFI book
