Tuning

VE Tune | Spark Tune | Transmission Tune | Minor Tweaks | Data Logging

| Readiness Sensor Tuning |

Contained in the pages above is my findings and my own personal tune data for the 3800 v6 (my camaro) using Hp Tuners software. I take no responsibility should you choose to follow all of or part of my advice, use this information at your own risk.

Below is a list that I have put together over the years of meanings and explanations for Hp Tuners to make it easier to reference information for myself with regards to making changes. It contains some of Hp Tuners own definitions with some of my own explanations or further descriptions.
**This list is not complete, and will continue to be added to as the years go on. If you have something you would like to add, feel free to email me and I will gladly include it providing the information is accurate.

ENGINE
General
EGR
Min IAT this is the intake air temperature requirement that must be met in order for the EGR to be enabled. Below this temperature EGR is non functional.

Idle RPM
Target idle speed This is the idle speed that your car attempts to achieve when the following conditions are met.

P/N (park Neutral) have the desired rpm settings in relative to the engine coolant temperature.
In Gear the same applies. This gives you the option gives you flexibility in your tune of having two different desired idles for the same temperature, but dependant on if you are in Park/neutral or in gear.

Fuel Control
General
Stoich AFR- This is ideal air fuel ratio in which you will get the fullest combustion during cruise. Stoich from the factory is set at 14.7 (14.68), however the stoich afr changes based on what is added into your gasoline. The more ethanol present in your gas, the lower your stoich point will be. 0% ethanol in your gasoline yields a 14.7 afr as stoich, while 10% ethanol in your gasoline yields a 14.1 afr as stoich. Adjust your tune accordingly. I currently have my tune set to 14.4 stoich as I feel this is a good medium as you are guaranteed to have ethanol in your gasoline these days.

Injector Control
Flow rate vs KPA- This is your injector sizing table. It lets the pcm know what size fuel injectors are running in the car at any one given time. Since the fuel pressure in your car will change at different manifold vacuum pressures (AKA when under load such as at wide open throttle as opposed to at idle or cruise) the table allows you to adjust the “true” size of the injectors throughout that range.

Skew vs Cylinder- This allows you to skew the amount of fuel into any cylinder in your vehicle. You can either add more fuel to particular cylinders, or subtract fuel. This function is more for independent cylinder tuning.

Fuel Cutoff
RPM limits, Cutoff RPM Vs. Gear- You have both a cutoff and resume table here. Cutoff is the rpm threshold that the car will cut the fuel supply going to the cylinders for the respective scenarios: PN- Park/neutral, Reverse, In gear.

Resume is the point in which the car will begin to add fuel back to the cylinders once the cutoff has been initiated.

Open Loop & Closed Loop
Delay- this table is used to set how much time the car delays in seconds after startup before it will enter into closed loop. The delay time is based upon your coolant temperature. Usually the warmer the coolant, the less of a delay time will be needed to enter into closed loop.

Coolant Temp- The coolant MUST reach this temperature IN ORDER to go into closed loop mode. This temperature must be met, regardless if the delay time above has passed. In order to force your tune into Open Loop you would set this temperature at an unattainable number

Power Enrich
PE Enable, Delay Vs. TPS- This is a delay in seconds that you can implement to prevent entering PE mode after achieving a certain throttle position. Example- if you have PE set to come on at 25% throttle, but you accelerate at 25% throttle regularily, you may set a certain amount of seconds that would delay the car from going into power enrichment mode once you hit 25% throttle. The throttle increments go in 5% throttle increases. 0’s mean no delay in entering Power enrichment.

PE Enable TPS, Hot- We do not have a table for “cold” so this is not coolant temperature dependant. This table is where you set when you want power enrichment to be enabled via Throttle position. The numbers inputed into the table are Throtte %, and it is relative to your engine RPM. This allows you to set power enrichment at lower RPMs to come on at a higher throttle position, while you can still set power enrichment to enable at a lower throttle position at higher engine RPM’s.

Base AFR vs ECT- This table is what your default air fuel ratio will revert to when you enter Power enrichment mode. This table is based off of you engine coolant temperature. This allows you to set richer/leaner values for different weather inclements.
This base table is what will be used for the Add vs RPM, and Add vs TPS tables. You usually set this table richer then what your stoich afr is set at.

Add vs TPS- This table is used to LEAN out your power enrichment table at desired throttle positions. It will not allow you to put a negative number, therefore it does NOT allow you to add fuel to your tune.

Add vs RPM-
 This table is used to add fuel based on RPM when in power enrichment mode. The seconds that are present in the table are so that you can add more fuel (if you wish) the longer you stay within PE mode under a certain rpm load. This table adds fuel based on your base afr vs ECT table afr.
For example in your tune if you know that you want to command a leaner mixture except in certain situations such as when the motor is under extreme load for a set amount of time (think climbing a steep hill) you can add a little bit of fuel when the car detects that you are at a certain throttle percentage (your PE enable Hot, and the determined number of seconds that you have been present at that load)

Spark Control
Main spark advance
High Octane- This is your spark advance timing that the car will attempt to utilize until it detects knock. If the car detects knock it will revert to the low octane table. Cylinder airmasss (g/cyl) is basically the load present on the engine. 0.92 cells would be hit at wide open throttle, while the ones in the middle will be hit at cruise.

Low octane- This is your spark advance timing that the car will attempt to utilize after it has detected knock. Again 0.92 cells would be hit at wide open throttle, while the ones in the middle will be hit at cruise.

Spark limiters
RPM Threshold- This is the RPM at which you will enable your rev limiter. At this threshold the pcm will cut the spark to the “commanded spark”

Commanded Spark- This is the specified spark that the pcm will cut to when the above RPM threshold has been met.

MPH vs Gear- When the following speeds have been reached in their respective gears, the “command spark” will be initiated to cut the timing (rev limiter)

ENGINE DIAGNOSTICS

Air flow
Maf sensor, Maf fail high- at this specified Hz frequency or higher, the pcm will automatically fail the Mass airflow sensor. If you have a tune that you would like to disable the MAF sensor, set this parameter to “0”

DTC’s

– This table is a list of all possible engine light codes. You can set which ones will enable the engine light to come on, and when/how the light will come on.
SES enable- This determines whether or not the engine will check for the code.
0- you will get an engine code the first time a fault is detected.
1- You will get a fault code the second time this error is reported
2- No engine light will be displayed in the dash.
3- No code will be retrieved and no error reported.

TRANSMISSION

Auto shift speed
Part throttle shift, Normal- This table is used for part throttle shift parameters. The numbers in grey going across the top are your throttle position, while the left top 3 coloumns are your upshifts, and the bottom 3 are the downshifts.

For the 1-2, 2-3, 3-4 shift your 100% throttle position should be set at the maximum mph/ km/h that your car should see in that gear.
For the first few cells (0, 6, 12) throttle position on the upshift, you should have the minimum speed inputed in which you will shift into the next gear. Example, if you have your 2-3 shift set at 30 mph for 6% throttle, then when you are traveling at 30mph and at 6% throttle, your car will upshift into 3rd gear.

For the 2-1, 3-2, 4-3, downshifts, your 100% throttle position should be set at the maximum mph/ km/h that you will be at prior to going into that lower gear. Example, if on the 2-1 downshift your 100% throttle is set at 30mph, then at 30mph or slower you will downshift into 1st gear, anything above 30mph you will downshift into 2nd, or 3rd gear respectively depending on your speed and table settings.

Performance- This is not used on the F-bodies, it is only if you have a “performance” select button (no not that nitrous button) on your transmission selector stick.

Hot-
 this table should be set the same as the normal table, unless you wish to change the settings slighty for a limp mode when your transmission runs in “hot mode”

Full throttle shift speed
Normal- this is the maximum speed you will be doing for your 1-2, 2-3, 3-4 upshifts, and the maximum speed you will be doing for your 2-1, 3-2, 4-3, downshifts. These numbers should correspond exactly with what is in the “100% throttle position” in the part throttle tables.

Performance- Again we do not have this table as F-bodies, you only have this if you have a performance button.

Hot- again this table should be set the same as the normal table, unless you are reducing numbers for a “limp mode”

Full throttle shift RPM
Normal- this is your max rpm that you will shift at at wide open throttle respectively for each upshift of gear.

Performance- We do not reference this as we do not have the performance buttons.

Hot- again this should be the same as the normal table, unless you are settting up a reduced speed/rpm limp mode.
***** ALL 3 TABLE CONDITIONS MUST BE MET IN ORDER FOR A SHIFT TO TAKE PLACE…THIS IS WHY IT IS IMPERATIVE THAT YOUR 100% THROTTLE POSITION BE THE SAME AS YOUR FULL THROTTLE SHIFT SPEED TABLE AND CORRESPOND WITH THE CORRECT RPM IN THE FULL THROTTLE SHIFT RPM TABLES.*****

SYSTEM

Fans
Fan 1 on Temp- This is the minimum temperature that must be reached by the coolant in order to turn fan 1 on.

Fan 1 off temp- When the coolant reaches this temperature, Fan 1 will turn off (but will come back on when it reaches the on temperature again)

Fan 1 enable speed At this speed if you have the A/C turned on, fan 1 will automatically be enabled.

Fan 1 disable speed- At this speed the fan will be disabled if you have you’re a/c on and are going faster then what is specified here.

Fan 2 on temp- This is the minimum temperature that must be reached by the coolant in order to turn fan 2 on.

Fan 2 off temp- When the coolant reaches this temperature, Fan 2 will turn off (but will come back on when it reaches the on temperature again)

Fan 2 enable speed- At this speed if you have the A/C turned on, fan 2 will automatically be enabled.

Fan 2 disable speed- At this speed the fan will be disabled if you have you’re a/c on and are going faster then what is specified here.

Ignition off
Disable Temp- If the car has this specified coolant temperature when you shut the ignition off, your fan will continue to run for the specified “run time”

Run Time- Is a time in seconds, when you turn your ignition off the pcm will reference the table above for the “disable temp”…if the coolant is hotter then the specified temperature, your fans will run for the specified number of seconds once the ignition is turned off.

A/C
General
Enable Min IAT- The intake air temperature must be above this temperature in order for the AC to enable.

Disable TPS- At this throttle position or higher, the A/C will be disabled.

Re-enable TPS- If the A/C was disabled, this is the throttle position that the car must fall to in order to re-enable the A/C

Disable ECT- At this engine coolant temperature the A/C will be disabled.

Re-enable ECT At this coolant temperature the A/C will be re-enabled.

Disable IGNV-
 At this ignition voltage the A/C will be disabled. You use this so that when the car is dropping in voltage (due to a failing alternator, or battery, whatever) it does not have the extra load from the A/C

Re-enable IGNV- The A/C will re-enable itself at this ignition voltage.

On Startup delay- This is the delay time in seconds that the A/C will not engage once the engine is fired up.

RPM disable- This table covers both park/netural, and In gear. The Ac will be disabled at the specified or higher RPMs, and it will re-enable at the specified and lower rpms.

SPEEDOMETER

Speed limiter- This is another speed limiter in which fuel/spark will be cut off at the specified speed per gear selected.

 

 

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