Difference between revisions of "Engine Control"
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* open v closed loop tuning<br /> | * open v closed loop tuning<br /> | ||
open loop tuning is doing it yourself, run the engine and check the outputs. closed loop tuning is usually done to a specific lambda and is handled by the ECM.<br /> | open loop tuning is doing it yourself, run the engine and check the outputs. closed loop tuning is usually done to a specific lambda and is handled by the ECM.<br /> | ||
| − | * dynamometer (should have its own page also | + | * dynamometer (should have its own page also |
| − | == | + | ===Spark Tuning=== |
| − | + | * mbt | |
| − | * mbt | ||
[diagram of spark timing on torque] | [diagram of spark timing on torque] | ||
* Knock is typically not an issue with a stock 4cyl. Not sure how to convey in 10 years of this I have never seen or heard evidence of it. | * Knock is typically not an issue with a stock 4cyl. Not sure how to convey in 10 years of this I have never seen or heard evidence of it. | ||
| − | == | + | ===Fuel Tuning=== |
| − | + | * duration | |
| − | * duration | + | ** lbt |
| − | ** lbt | + | * timing |
| − | * timing | ||
| − | ==Tuning | + | ===Tuning for Startup=== |
| − | == | + | ===Tuning for Idle=== |
Run lean, at least in the case of the 4cyls they do not seem to mind being 15+ | Run lean, at least in the case of the 4cyls they do not seem to mind being 15+ | ||
| − | == | + | ===Tuning For Quick Rev=== |
| − | =Closed v open loop engine control | + | ==Closed v open loop engine control== |
| − | * short term factors | + | * short term factors |
| − | * long term factors | + | * long term factors |
| − | * place in motorsport | + | * place in motorsport |
| − | =Data and Data Collection | + | ==Data and Data Collection== |
| − | * stuff needed to run the engine | + | * stuff needed to run the engine |
| − | ** cam sync | + | ** cam sync |
| − | ** load (alpha, map, maf) | + | ** load (alpha, map, maf) |
| − | ** rpm | + | ** rpm |
| − | * stuff needed for compensations | + | * stuff needed for compensations |
| − | ** IAT | + | ** IAT |
| − | ** map (for alpha-n) | + | ** map (for alpha-n) |
| − | * stuff you should get so you can figure out wth ur doing | + | * stuff you should get so you can figure out wth ur doing |
| − | ** oil pressure | + | ** oil pressure |
| − | ** coolant temp | + | ** coolant temp |
| − | * cool data so you can do custom engine stuff | + | * cool data so you can do custom engine stuff |
| − | ** cylinder pressure | + | ** cylinder pressure |
| − | ** knock sensor (cyl pressure can handle this if you have it | + | ** knock sensor (cyl pressure can handle this if you have it |
| − | ** fuel flow meter | + | ** fuel flow meter |
** cyl temperature | ** cyl temperature | ||
I'm sure there's stuff im forgetting | I'm sure there's stuff im forgetting | ||
Revision as of 13:09, 16 May 2020
Engine Control - put under engine or leave separate?
- Theory - spark, fuel control
- passive v active (wasted spark and carbs v PFI/DFI and spark control)
- passive v active (wasted spark and carbs v PFI/DFI and spark control)
- Tuning
- alpha-n
- common ecus
- alpha-n
- Custom cams
Contents
Theory
Passive
It is possible to run an engine without an engine control module.
Wasted spark such as yamaha wr450 before 2010
cbr is carb stock
Active
control spark - timing
control fuel - timing, duration (can't really change angle or placement so we put that under fuel system design, not here)
control air - throttle
control temperature - radiator redirect valve, fan control
control valve timing, valve lift (not electronically tunable, but still control, i'd be willing to put this under intake if that's a better place)
Tuning
Engine tuning is the idea of changing the independent inputs to the engine to achieve a desired goal. The inputs available to tune depend on the engine control strategy. Usually this goal is peak engine torque at every operating condition.
- engine control strategies
The most common engine control strategy (at least in fsae, not sure about the galaxy brains across the pond) is alpha-n.
There is also speed-density.
Not sure if there's a fancy name for maf control, not sure if anyone uses it either.
Theory
- dithering
need to make this clearer
Since the engine torque output is a non-linear function of many variables, and the resultant surface isn't analytically determinate, the torque surface is navigated by dithering. This involves running the engine on a dynamometer and, for each engine control variable, taking small steps in a direction and determining the effect the small step has on the torque. If the result is a decrease in torque, another direction is pursed. By chasing the direction of increasing torque for every operating condition, the engine control is optimized. this is just one big gradient ascent, but very badass.
- open v closed loop tuning
open loop tuning is doing it yourself, run the engine and check the outputs. closed loop tuning is usually done to a specific lambda and is handled by the ECM.
- dynamometer (should have its own page also
Spark Tuning
- mbt
[diagram of spark timing on torque]
- Knock is typically not an issue with a stock 4cyl. Not sure how to convey in 10 years of this I have never seen or heard evidence of it.
Fuel Tuning
- duration
- lbt
- timing
Tuning for Startup
Tuning for Idle
Run lean, at least in the case of the 4cyls they do not seem to mind being 15+
Tuning For Quick Rev
Closed v open loop engine control
- short term factors
- long term factors
- place in motorsport
Data and Data Collection
- stuff needed to run the engine
- cam sync
- load (alpha, map, maf)
- rpm
- stuff needed for compensations
- IAT
- map (for alpha-n)
- stuff you should get so you can figure out wth ur doing
- oil pressure
- coolant temp
- cool data so you can do custom engine stuff
- cylinder pressure
- knock sensor (cyl pressure can handle this if you have it
- fuel flow meter
- cyl temperature
I'm sure there's stuff im forgetting