it might be obvious to some, and i have only just got my car running, but the order for tuning isn't totally clear to me.
1) turn ignition on (powers up MJ)
2) MJ reads FLASH that is already written
3) If you want to modify do you:
3a) open the tuning config file and edit then "put" to the FLASH BIOS
3b) read the current one (car is running at this point) and edit, then "put" to BIOS
4) aside from seat of the pants tuning - how is everyone tuning these? i've used DannyP's config as his engine is similar to mine.
Is this stuff written down somewhere? I've searched the "how to" wiki and the detailed info sort of drops off once you get the car running.
Thanks
Can someone walk me through the basic tuning procedure
Moderators: JeffC, rdoherty, stieg, brentp
Hi Paul,
Here's the operation guide that outlines how to retrieve, edit and write back the values to the controller.
http://www.autosportlabs.net/MJLJ_V4_Op ... figuration
(this is for V4, there's a corresponding version for the V3 controller).
In a nutshell:
1. Read values from MJLJ (with MJLJ powered up).
2. Edit ignition map / bins as necessary
3. Write values back to controller's RAM as you tune
4. When complete, FLASH values to controller's non-volatile memory- so values are retained when power is turned off.
Reading/writing files on your computer is an optional step- used to save your ignition config to your computer, or load someone else's ignition config.
As for actual tuning- we do need an article in the wiki on ignition tuning theory. Very broadly, the basic principal is to dial in ignition advance such that peak cylinder pressure occurs right after TDC on the power stroke.
In reality, this varies based on engine design, cylinder head design, spark plug location, fuel mixture, etc. etc.
This is a good article discussing the art and science behind the tuning process:
http://www.highperformancepontiac.com/t ... index.html
Many will take the vehicle to a dyno and perform an iterative tuning process under a watchful eye of the experienced operator, finding the ignition advance which safely yields maximum torque under varying operating conditions (high / low load, high /low RPM). Others may interactively tune on a track or empty road- a more crude process but can still be effective.
Hope this helps,
Here's the operation guide that outlines how to retrieve, edit and write back the values to the controller.
http://www.autosportlabs.net/MJLJ_V4_Op ... figuration
(this is for V4, there's a corresponding version for the V3 controller).
In a nutshell:
1. Read values from MJLJ (with MJLJ powered up).
2. Edit ignition map / bins as necessary
3. Write values back to controller's RAM as you tune
4. When complete, FLASH values to controller's non-volatile memory- so values are retained when power is turned off.
Reading/writing files on your computer is an optional step- used to save your ignition config to your computer, or load someone else's ignition config.
As for actual tuning- we do need an article in the wiki on ignition tuning theory. Very broadly, the basic principal is to dial in ignition advance such that peak cylinder pressure occurs right after TDC on the power stroke.
In reality, this varies based on engine design, cylinder head design, spark plug location, fuel mixture, etc. etc.
This is a good article discussing the art and science behind the tuning process:
http://www.highperformancepontiac.com/t ... index.html
Many will take the vehicle to a dyno and perform an iterative tuning process under a watchful eye of the experienced operator, finding the ignition advance which safely yields maximum torque under varying operating conditions (high / low load, high /low RPM). Others may interactively tune on a track or empty road- a more crude process but can still be effective.
Hope this helps,