93 5.0 MSPNP2 tuning ?s

You should also log 'flow' to see the flow # so you can build the curve. If it does not exist you can create it in megalog viewer with a custom field.

Flow would be- [load] * [rpm]

Thanks! I'll try that when I get a chance. How'd you get so smart to be able to create stuff that's not even there? I'm glad you have to help the rest of us....
 
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@a91what After sleeping on it, I think I got a grasp of what the MAT/CLT correction does. So let's say clt temp is 200* idle flow is 20000-24000 and MAT is 140* and if the MAT/CLT correction at that point is 40% it'd be
((CLT-MAT)×corr%)+MAT=new corrected MAT. So
((200-140)×.4)+140=164* MAT. If correction was 30% it'd be 158* MAT. Am I thinking correctly on what this table does now?
 
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That is correct, remember you only want it to affect the mat temp at idle. Doing this will force the MAT reading at all idle conditions in a tighter area of the correction curve.
You could even go more aggressive with blended % for instance 50% would tighten the numbers even further... this will take a bit of experimentation
 
That is correct, remember you only want it to affect the mat temp at idle. Doing this will force the MAT reading at all idle conditions in a tighter area of the correction curve.
You could even go more aggressive with blended % for instance 50% would tighten the numbers even further... this will take a bit of experimentation

Ok. I was planning on having the MAT/CLT table to 0% by around 45000 air flow. That be a good cut off point?
Also, on the VE table, I should only need to increase the cells from 45 kpa down and 1200 rpm and down. The rest of the table should be fine the way it is? Correct?
 
yes :shrug:

make the changes and datalog with a few revs ect... then we can look and see what the flow# is above idle at cruise and use this to set the curve, without that info i cant really give you a good starting point

Ok. I changed the MAT/CLT table and did a drive and some free revs. What exactly am I looking for? It looks like Air Flow @ idle is about 30000. Cruising at 1800 rpm it's around 78000
 
Ok perfect so you want to adjust the curve so that all the blend is gone by 60000 flow.

Then retune the idle fuel and see if it helps the hot start issue.
Keep up the good work your currently doing what most are to afraid to do, use tables they did not previously understand.
 
Ok perfect so you want to adjust the curve so that all the blend is gone by 60000 flow.

Then retune the idle fuel and see if it helps the hot start issue.
Keep up the good work your currently doing what most are to afraid to do, use tables they did not previously understand.

The interesting thing I noticed is the flow on the log shows higher than the green dot on the chart on TS. While idling, the dot shows around 22000 datalog shows around 30000. Anything to be concerned about?

So last column on the MAT/CLT chart put close to 60000 and 0%

Right now I have it at 100% @ 0 flow about 45% @ 23000 then would go to 0% @ 60000
 
Ok. I retuned the ve table for idle. Went for a drive while dataloging. Ran ve analyze only a couple was off 2, rest was 1 or less, so I didn't change anything there.
Now to the hot start. Starts up fine. Runs fine while ASE is on cause I extended the taper on the last block to last longer. When that's over (about a minute or so) it'll run lean at 14.7 (I have it set at 13.7 @ idle) slowly tapering down to 13.7 after about 2 minutes after ASE is over. Much better.
But why does it still run lean for a little while? And slowly taper down even though the MAT doesn't seem to change much?
Now to see if the ve table is still ok when cold.....

I should add that before I did this MAT/ CLT the afr did not come down till I drove it. Now it will after 2 minutues.
 
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The interesting thing I noticed is the flow on the log shows higher than the green dot on the chart on TS. While idling, the dot shows around 22000 datalog shows around 30000. Anything to be concerned about?

So last column on the MAT/CLT chart put close to 60000 and 0%

Right now I have it at 100% @ 0 flow about 45% @ 23000 then would go to 0% @ 60000
This has everything to do with our math in megalog viewer. Without playing with it to see how the determine the flow, likely we are missing a term in the equation. It's good you can see the dot.
 
Ok. I retuned the ve table for idle. Went for a drive while dataloging. Ran ve analyze only a couple was off 2, rest was 1 or less, so I didn't change anything there.
Now to the hot start. Starts up fine. Runs fine while ASE is on cause I extended the taper on the last block to last longer. When that's over (about a minute or so) it'll run lean at 14.7 (I have it set at 13.7 @ idle) slowly tapering down to 13.7 after about 2 minutes after ASE is over. Much better.
But why does it still run lean for a little while? And slowly taper down even though the MAT doesn't seem to change much?
Now to see if the ve table is still ok when cold.....

I should add that before I did this MAT/ CLT the afr did not come down till I drove it. Now it will after 2 minutues.
I would need to see the datalog to help answer that.
 
OK. Here is the tune and this first log is from a 145* MAT start. It is a little rich until it gets to 160* MAT then it's close... I'll post a hot start here as soon as I get it done.
 

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  • 145degstart.msl
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Here's one from 180* MAT start. This isn't quite heat soaked like it will get after driven for awhile then sit 10 minutes, but it still shows it running a little lean for a couple minutes then settling down to 13.7.
 

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Cool so lets look at the two datalogs with some fields pulled up, the graphs i want you to focus on are the bottom set. These have the fuel enrichment's pulled up, the AFR is on the top graph.
I think we need to re-enable the mat correction at startup and see what happens and re-evaluate these same fields. you will notice the FUEL: AIR CORRECTION field is 100% then abruptly changes and alters the fuel amount after so many seconds [drops about the same time that ASE tapers off] causing the lean spot.

MATCLT start 145.PNG
MATCLT start 181.PNG