Tip in Acceleration Solved- Need Input for Write-up
05-01-19, 01:28 PM
#26
A few questions:
You have suggestions for mildly modified cars in there. I consider my car in that category with smoothed stock ports and bolt ons. Rather than start completely from scratch would you suggest giving your recommendations a try and then log? Seems like the changes aren't that drastic and the worst that could happen is a slightly rich condition under accel. My AFR's are fairly dialed in for WOT boost, but I've never specifically logged for acceleration.
If I were to do some logs you suggest starting at 3000 rpm cruising and doing various acceleration trials. Then I would make the suggested changes (in both tables) until the AFR's are on target would you move on to the other RPM's?
Also...Changing both tables at once seems really daunting...
You have suggestions for mildly modified cars in there. I consider my car in that category with smoothed stock ports and bolt ons. Rather than start completely from scratch would you suggest giving your recommendations a try and then log? Seems like the changes aren't that drastic and the worst that could happen is a slightly rich condition under accel. My AFR's are fairly dialed in for WOT boost, but I've never specifically logged for acceleration.
If I were to do some logs you suggest starting at 3000 rpm cruising and doing various acceleration trials. Then I would make the suggested changes (in both tables) until the AFR's are on target would you move on to the other RPM's?
Also...Changing both tables at once seems really daunting...
05-01-19, 02:09 PM
#27
I'm working on this exact same issue.
Went up in turbo size and exhaust runner size, and these two changes dramatically, I mean very dramatically, affected the tranient fuel. Initially a very big lean spike lasting as long as almost 1000 to 1250ms on 3rd gear WOT smashes. As soon as boost hits, it would jump right to target AFR. Ended up requiring almost double the amount of transient fuel synronchrous enrichment amounts in mid rpm range, and at least 25% longer duration applied to % per second changes.
Using a haltech elite so I realize it's not comparable terms.
But, the bottom line was, just changing the compressor, to a larger, and freeing up back pressure, had the same change as if the engine went up to a much larger throttle. In fact driving low throttle it's so much more sensitive that it required reducing timing.
So for anyone moving up turbo sizes I would totally expect this to alter transient fuel curve even if you run the same overall power and boost levels as before.
This stuff gets really tricky to nail down perfectly on any car but it sure is fun when you nail it!
Went up in turbo size and exhaust runner size, and these two changes dramatically, I mean very dramatically, affected the tranient fuel. Initially a very big lean spike lasting as long as almost 1000 to 1250ms on 3rd gear WOT smashes. As soon as boost hits, it would jump right to target AFR. Ended up requiring almost double the amount of transient fuel synronchrous enrichment amounts in mid rpm range, and at least 25% longer duration applied to % per second changes.
Using a haltech elite so I realize it's not comparable terms.
But, the bottom line was, just changing the compressor, to a larger, and freeing up back pressure, had the same change as if the engine went up to a much larger throttle. In fact driving low throttle it's so much more sensitive that it required reducing timing.
So for anyone moving up turbo sizes I would totally expect this to alter transient fuel curve even if you run the same overall power and boost levels as before.
This stuff gets really tricky to nail down perfectly on any car but it sure is fun when you nail it!
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mikejokich (05-01-19)
05-01-19, 03:02 PM
#28
Rotary Enthusiast
iTrader: (32)
I have posted the write up for Acceleration Enrichment Solved for the Power FC in the Power FC forum section. Here is the link.
https://www.rx7club.com/power-fc-for.../#post12344738
I can help answer any questions you may have and help others to achieve much improved accelerations. I was only able to give recommendations for lightly modified cars at this time since I don't have data for other more moderately and heavily modified cars.
Mike
https://www.rx7club.com/power-fc-for.../#post12344738
I can help answer any questions you may have and help others to achieve much improved accelerations. I was only able to give recommendations for lightly modified cars at this time since I don't have data for other more moderately and heavily modified cars.
Mike
05-01-19, 09:37 PM
#29
A few questions:
You have suggestions for mildly modified cars in there. I consider my car in that category with smoothed stock ports and bolt ons. Rather than start completely from scratch would you suggest giving your recommendations a try and then log? Seems like the changes aren't that drastic and the worst that could happen is a slightly rich condition under accel. My AFR's are fairly dialed in for WOT boost, but I've never specifically logged for acceleration.
If I were to do some logs you suggest starting at 3000 rpm cruising and doing various acceleration trials. Then I would make the suggested changes (in both tables) until the AFR's are on target would you move on to the other RPM's?
Also...Changing both tables at once seems really daunting...
You have suggestions for mildly modified cars in there. I consider my car in that category with smoothed stock ports and bolt ons. Rather than start completely from scratch would you suggest giving your recommendations a try and then log? Seems like the changes aren't that drastic and the worst that could happen is a slightly rich condition under accel. My AFR's are fairly dialed in for WOT boost, but I've never specifically logged for acceleration.
If I were to do some logs you suggest starting at 3000 rpm cruising and doing various acceleration trials. Then I would make the suggested changes (in both tables) until the AFR's are on target would you move on to the other RPM's?
Also...Changing both tables at once seems really daunting...
To answer one of your questions, I would not change one table at a time. They are too interdependent on each other. The Inj. vs TPS1 has to be changed in the second and third rows for sure to start. You can then just concentrate on one rpm value at a time on the Accelerate Inj table. 3000 rpm is the most important since this is where 50% or more of our accelerations start from. Logging accelerations with the stock tables in place first I believe is important in the beginning to see exactly how lean you are.
Mike
05-30-19, 10:21 PM
#30
Everyone,
I finished a Quick Guide for Acceleration Enrichment write-up for the Power FC. I added it to the entire document and made some changes to the original document to fix errors and to update my newest AE tables I now use following further testing. The first 5 pages are the Quick Guide followed by the Full Guide. The Quick Guide will make it easier to make changes and is less in depth as compared to the Full Guide. The new guide is posted in the Power FC forum.
Mike
I finished a Quick Guide for Acceleration Enrichment write-up for the Power FC. I added it to the entire document and made some changes to the original document to fix errors and to update my newest AE tables I now use following further testing. The first 5 pages are the Quick Guide followed by the Full Guide. The Quick Guide will make it easier to make changes and is less in depth as compared to the Full Guide. The new guide is posted in the Power FC forum.
Mike
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