Why do i feel like i should be going the other way? I want to end injection later to move injection later. Sorry brain's a bit fuzzy from this green beer. Cheers btw
smart enough to feel stupid
If you look at a degree wheel you can see that 66 eiot backs up the eiot. The plan is to make the injectors spray on a closed intake valve not a open exhaust valve. I'm looking at my cam sheet and the degree wheel to help figure out why removing from the 180 adds to the 60 hex. Maybe someone can chime it to help explain it. I'll try and see what I come up with. Do you still have your cam card ? It may help understand. If not we have the same cam I can post mine
I drew up a chart to make this easier to understand.
http://www.sand-hill.uk/Terminal_Crazy/EoIT/
It's EoIT_Chart.pdf in that directory
Hope you find it useful
Mitch
'95 Z28 M6 -Just the odd mod.
'80 350 A3 C3 Corvette - recent addition.
Great chart ,certainly makes it clear. Why not end timing at say 540 at bdc of the intake stroke? I know atomization is a factor but if you're having trouble with overlap from a big cam wouldn't spraying late and right in the cylinder be more the way to go? I guess i could just try it and see what happens
smart enough to feel stupid
If you look in that directory, there is a file of an idle I did with various eoit settings and averaged out the injection pw times.
You can see the pw reducing as the eoit is moved further away from the intake opening.
Whether that improves the idle is up to you.
Ymmv
Mitch
'95 Z28 M6 -Just the odd mod.
'80 350 A3 C3 Corvette - recent addition.
Idle isn't really the issue as much as cruising or drivability in general really. I can get good idle at 180 but cant get a remotely decent drive out of it. I just tried 540 and 146 so 20 and 66 at 146 it was lean trying to add fuel and at 540 rich pulling fuel out. I guess i could just stick with 146 and toss on my base map drive it use trimalyzer and see what i get i need to put miles on it anyway
smart enough to feel stupid
Yes that is more than likely what we would have to do because of the 27* cam overlap I have the same cam as you do. The reason to spray on a closed exhaust valve is so the gas can vaporize from the heat of the motor witch will give more compleat fuel burn. But with the cam overlap it may not be possible to get it perfectly were it needs to be
here is our cam specs put on a cam wheel just for visual reference
I'm probably going to run it at the $66 trim it in close and see if there is any improvement in drivability. Another thing that i might try is setting the blm limit to like 115 120 because when i get the surge it's trying to pull fuel way too much and that's not working out with this combo. So i figure if i can stop it blowing fuel out the exhaust and persuade it to fuel as I'm telling it to i might just be able to make this thing drive with some manners.
smart enough to feel stupid
LoL yes trying different things to see what it likes is Best if you get it running better you can always improve the tune when you know what it wants. I have not had no seat time to tune my ve tables yet hopefully will be able to soon
What is your build information ? I can share my current bin maybe you can look it over it may help you pin down the difference between the 2 and give you some other things to look at
actully this is what You want to do, the later EOIT happens the later PCM starts to spray. The more EVC the less unburnt fuel is evacuated thru exhaust and by that engine works more efficient. This also reduces fuel smell on idle/cruise on engines with big overlap cams and helps witd drivebality
best regards
Last edited by WASyL; 03-17-2019 at 01:27 PM.
also found this on HPTuners board for LS1 PCM but actually it apply to any fuel injected engine:
- By adjusting (increasing) EOIT "Normal" , you can reduce or eliminate most exhaust smell at idle when not running cats on a cammed LS1
- LS1 PCMs are limited on what you can control, not 1 value solves all
- .11 = 10 degrees of crank rotation
- Leave the "Injection Timing Boundary" at 6.50 (stock value)
- Leave the "Makeup Injection vs ECT" at (stock values)
- Don't oversize your injectors for your application
- The bigger the cam and more overlap the higher the "Normal Injecting Timing vs ECT" values
- EOIT normal values can range from 6.0 all the way up to 6.5, depending on valve events
best regards
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