Megasquirt Saturn

Update your progress on your various car projects.

Moderators: MostMint, wxo, Fred32v, Basement Paul, ttamrettus

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MostMint
Posts: 2714
Joined: Thu Jul 21, 2005 12:11 pm
Location: planning a race

Re: Megasquirt Saturn

Post by MostMint »

On 12/30 I visited Tiresmoker central. We were able to fix the fan relay so now Dave can proceed with getting that connected to the Megasquirt. We also took the car around the block a few times to help the new ECU learning. That was made entertaining by the inch of snow on the roads and the summer tires on the car. I don't know if we ever exceeded 25 mph vehicle speed though there were several time I opened it up through 3rd gear. Learned some things about the new ECU and a list of little things to address. Good progress so far.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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MostMint
Posts: 2714
Joined: Thu Jul 21, 2005 12:11 pm
Location: planning a race

Re: Megasquirt Saturn

Post by MostMint »

Tiresmoker piloted the Saturn through the bitter cold on its return trip home on the Megasquirt today. I got a 101 primer and my PC is now set up. Yikes I have to learn how to make this thing work. Dave has us at a good starting point. I have to learn to speak Megasquirt before I will be able to make much impact.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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MostMint
Posts: 2714
Joined: Thu Jul 21, 2005 12:11 pm
Location: planning a race

Re: Megasquirt Saturn

Post by MostMint »

So I am a few days into this I have learned to speak the language a little.

The first thing I did was set the timing table to best match my understanding of timing roughly translating my mechanical understanding into a table. I quickly learned it liked more initial lead at low RPMs and WOT so I made some adjustments there.

There are so many things to control, it's like old school tuning on steroids!

I developed a system to keep track of the tunes and major adjustments I made in each tune.
V1 = as delivered from Tiresmoker
V2 = updated timing table and changed lower RPM air fuel ratio target to 14.7
V3 = started working on cold start and the warm up cycle. Our baseline settings are quite rich to where I would have to crack the throttle to let air in. Brought this down better but at the end the car would not idle. Still did not have ability to control idle air.
V4 = adjusted idle air control, reduced flood clear TPS% to 80% - this give operator ability to stop incoming fuel if you push the throttle down 80% or more. Also adjusted maximum lead from 38 to 34 degrees in the lead table.
V4A = more work on the warm up cycle.
V4B = tonight I was able to do complete cold start from 30 degrees coolant temp and make further refinements.

Using the software is easy, applying updates is easy. Using TunerStudio you can monitor everything real time. Every table and setting can be pulled up and it will show you where the car is operating on that table. This can be quite powerful methinks once I get a really good handle on it.

Some things I have been working on so far
- ignition table - desired timing lead in a table of RPM vs throttle open amount
- air fuel ratio table - desired ratio in table of RPM vs throttle open amount
- warm up enrichment. This tells how much extra fuel to put in while the car is warming up - it is a graph of enrichment amt vs engine temp
- after start enrichment. How much extra to kick in at the start - graph of enrichment vs engine temp
- after start enrichment taper. How long after start to use after start enrichment
- cranking pulse width - how long to keep injector open while cranking
- idle air control - how far to open idle air control vs engine coolant temp. Yes you can change the idle air content based on engine temp!

Dave - the WUE and Idle Warmup/Duty tables share temperature ranges, so if you move a temp in the table on one it automatically moves it on the other. I will look for others that have this connection.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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MostMint
Posts: 2714
Joined: Thu Jul 21, 2005 12:11 pm
Location: planning a race

Re: Megasquirt Saturn

Post by MostMint »

More table compares tonight: Each group shares the same temp scale:

Group 1:
Priming Pulse%
Cranking Pulse %
ASE Enrichment
ASE Enrichment Taper

Group 2:
Warmup Enrichment
Stepper Idle Warmup Position
Cold Advance

This is important to know because if you move a temp point on the graph all the settings in the other tables automatically come along with it, which may or may not be what you want.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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