EOIT RPM vs ECT

[hapisok]

I've been doing some extensive research between the GEN 3 & GEN 4 sections regarding EIOT. My tune requires some tweaking due to surging and bucking in the lower RPM ranges after paying a "well known" shop to tune my 2010 LS3 camaro M6.

i added 30 globally to the ECT table and it made a noticeable difference (although this was a rough guess as im still working the maths). i believe im on the right track now that i know my timing events at .006.

anyhow, my question is why make changes to the ECT table vs RPM? it makes more sense that i'd be able to dial in Normal RPM EOIT where ECT would be more of a guessing game.

any guidance would be appreciated.

thanks


CAM SPEC:
Lunati custom cam by Ed Curtis
227/237 @ .050 LSA 114

[hapisok]

added files n stuff

uploaded the EOIT calculator made by DSTECK

original tune by VA SPEED

tweaked tune of EOIT NORMAL RPM using the spread sheet

log file

after giving it a good drive, a lot of the bucking cleared up although there is still minor bucking between 1000-1200RPM. i THINK this may be due to the idle airflow tables needing to be tweaked...i think.

anyhow...BUMP!

[schpenxel]

Boundary - ECT - RPM = EOI target

You can change any of the three if you want, the bottom line is EOI target anyway you slice it

Keep in mind the color "shading" in that calculator was not meant to say this is right and this is wrong.. it was just meant to make the sheet more visual

I can't tell you best settings to use though

[hapisok]

Thanks schp.

I used the output EIO target number and adjusted the rpm to match the target based on each RPM range and measured pulse width. Seems to have gotten things close to being hammered out... Still have some work to do though.

[07GTS]

make sure u go the right way adding to the ECT table advances the eoit, adding to the boundary delays eoit, adding to the rpm table advances eoit, if u start with boundary then any number in the ECT and RPM table are substracted from the boundary number to give u actual eoit, then your IPW in crank deg is substracted from that last number to give u SOIT then u can work that out with your cam, it is all a little rough but gives i an idea of where things are

[SMEC]

I've been racking my brain on this calculator deal...how and where do you edit it?

[schpenxel]

Cells in blue are the only things you can edit if you're referring to the calculator posted earlier

[hapisok]

I've been racking my brain on this calculator deal...how and where do you edit it?

knowing your cam specs, you need to figure out what your timing events are based on .006 (advertised), not .050.

my cam spec is 227/237 @ .050
advertised spec 277.287 @ .006

this is the calculator i used to get my .006 numbers: http://www.wallaceracing.com/cam-deg-calc.php

using the EVC from the cam-deg-calc, you input that into the upper right hand corner of the spreadsheet.

it will calculate your target EOI and that is the number you want to shoot for by adjusting either:
- boundary
- ect EOI
- rpm EOI

DSTECK explains it as he is the one who created the spreadsheet:

http://www.hptuners.com/forum/showth...lculated/page6 post 108

hope this helps

[Michael_D]

Have fun picking pulse width values, for any given rpm, into plug into the sheet. Log a variety of different accelerations, from mellow to WOT.

I'm beginning to think its pointless to change anything over 1500-1800, and anything under that us just idle or cruising load in overdrive gears.

[07GTS]

i got a good response from adjusting to for idle and cruise areas, but the faster u spin the more the overlap is beginning to suck air in and not straight out like the slower speeds, i havnt made adjustments on the dyno for it but just going for a drive i can tell if i delay it too much up top it will feel like it looses power or just dosnt deliver as smoothly as normal, up top mine likes to have EOIT just as the intake valve opens then it just pulls smooth all the way to redline, i am boosted tho could be different for N/A

[GHuggins]

i got a good response from adjusting to for idle and cruise areas, but the faster u spin the more the overlap is beginning to suck air in and not straight out like the slower speeds, i havnt made adjustments on the dyno for it but just going for a drive i can tell if i delay it too much up top it will feel like it looses power or just dosnt deliver as smoothly as normal, up top mine likes to have EOIT just as the intake valve opens then it just pulls smooth all the way to redline, i am boosted tho could be different for N/A

Dyno might show different? In the higher rpms I've had pretty decent luck targeting around bdc of the pistons stroke.

[07GTS]

Dyno might show different? In the higher rpms I've had pretty decent luck targeting around bdc of the pistons stroke.

when the car is back on the road again ill be getting to a dyno was going to give it a go to see if it actually made any difference, but i noticed the WB did develop some little lean spikes up top (i have constant WB installed for street tuning) only when the eoit was delayed more up top not sure if it was little missfires maby but i just changed it back and then fueling stayed smooth again, maby there is a sweet spot in the middle before it gets the lean spikes that works best..?

[GHuggins]

You may have retarded it too much - what was your injector duty cycle at this time? Only reason I ask is because all though we target around bdc of the pistons stroke for the boundary angle - the injector will still spray the majority of the time durring wot on a closed intake valve - also why some will not "notice" a difference up top - you'll usually only see it on a dyno... If it's retarded to the point to where it's still spraying when the valve is pretty much closed, you'll see problems too - try to target 30 degrees before .006" closing specs for your boundary angle... Use the ect table to dial in soi... Between those two tables on the gen 4's, you should be able to dial it in pretty well...

[07GTS]

IPW is about the 9-10ms WOT (i have massive injectors 15psi boost e85) and at that time i was targeting the BDC for eoit so i should still have had 180+ deg of IVO time, cam is @.006 285 285 114, i might have to see if i can find the tune i was using and see what i done, but for now i just stuffed something trying a flash with 3.0 for first time to link vats now cant use anything ill have to start another thread and see what support want to help fix it

[BigMike42]

Keep in mind gen4s are already fairly pushed back. With your cam specs, the stock settings may already be optimal. It's not as early an injection point as a gen3. Low RPM bucking can usually be fixed by relaxing spark. What is your spark when it bucks? You want to make sure it's completely flatlined, any small changes in spark cause bucking at low rpm. Even 2 degrees will do it.

[07GTS]

pretty much all i done with eoit was change the ECT table to 85 which delayed it all 25 deg, so the stock settings are pretty close but just have to remember to add the makeup deg into the calculations also, does anyone know what the makeup is for ? i found if i go below 10 deg the makeup fueling goes a little funny and that's in OL i was thinking it might be for the CL STFT corrections ?