Agree 100%. I've found most LT4 Supercharged setups actually like a richer Flex Fuel mixture than you COULD safely run.Originally Posted by Alvin
Agree 100%. I've found most LT4 Supercharged setups actually like a richer Flex Fuel mixture than you COULD safely run.
Leaner is not always meaner.
The spark plug and pistons don't know you're running ethanol vs gasoline. They really only see total cylinder filling, temperature, pressure, and carbon balance. Working in units of lambda (phi) keeps you in the ballpark for carbon balance as fuel blends change. I usually end up pretty much the same lambda for pump gas vs ethanol. The big difference ends up in spark tolerance.
Do you have a 12678 Flex Fuel Spark table used on a LT4?
All Gen V ECU's have the flex fuel table available.
That has nothing to do with MAF. Notice, its under the 'fuel' tab. That's a flow rate mult due to ethanol being denser than gasoline...
Recommend you remove the edit to the injector flow rate mult table. It will be over-fueling by 7-8% at the top of the ethanol range now...
Hmmm, I've fixed several doing it that way, as all of the multipliers on the gen V's seem to work by lower numbers add more fuel. They're almost always lean if you leave the stock setting in there. In fact 30% if you run full E and the OP's is already 10% lean with the stock setting on the low E content he's running.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
now that idle is ok im right back here. when ever i go to wot it only shows 85% and its still feeling off when flooring it. not sure wat im doing wrong with all this information that tells me different things. this is where im at with the tune. it pulls but idk something is off. can anyone see something in log? thanks in advance.
here is an code that pop up but went away while driving. maybe in need to check a plug or wire
ok no idea how to upload pic but it was p0300 and p0307 which is random misfire and cyl 7 misfire. ill start by checkin cyl 7
maybe i messed wit something when installing flex fuel sensor
It's for sure down a cylinder on the drivers side. Also the stoich table still hasn't been correct yet.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
for 100% is it 8.9 or 9.8?
Copy the table from my trucks file.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
good morning. ok so i updated the stoich table, then i checked the wires and number 7 did feel loose pushed all way on plug. let the car warm up and then went cruising for a bit. dont want to do wot log yet till im sure its safe. here are some logs of driving around. did feal bit weird down low 1st n second gear but mainly taking off. thanks for help again. how do fuel trims look? its a manual btw
Last edited by wtf777; 5 Days Ago at 09:58 AM.
I would highly advise going back to gas and verifying your fueling to be 100% there, but until you update that density multiplier for the 30% extra requirement of ethanol, it's going to stay super lean on ethanol - are you not looking at your trims - right now your'e removing instead of adding for the ethanol with the stock multiplier.... Like I said, I've tuned lots and lots of these and understand how to calibrate those tables better than most.... Now if you really want it dialed in you can stop the ethanol at those specific amounts and adjust each multiplier accordingly. That is how I do them.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
just to make sure. under fuel>general>and then under flow rate.is that the correct density multiplier, do i just times the whole table by 1.30? also do i need to modify the alcohol multiplier next to it? gas station i go to has e65.
It's the alcohol multiplier table. That's what multiplies against the density. Quick and easy thing to do is to put the same one in that the SD side uses. Won't be right but its a heck of a lot better than the stock one. Right now you're over 30 % lean at times running the stock table.
The stock flow rate mult factors in the actual fucking density of the fuel. Go look up the density of ethanol, then the rough density of gasoline, and divide the two. Compare to that table. What does that tell you? Follow the bread crumbs, jesus. If you're going to just hack shit up, you might as well rape the PE table like its 2005.
Do you have a wideband in the car? If not, then you're flying blind. The mods you're tuning for are pretty simple, you might want to consider hiring a remote tuner to get it fixed up for you and then you can have a safe starting point to toy with the tune. For you mods you don't need to set the Alcohol PE any different than the Gasoline PE. You don't need to touch any density multipliers. But you do need to use the correct stoich values, populate the Ethanol Spark stuff, enable the Flex Diag and sensor stuff, and address the Torque Model for Ethanol. Early Gen V ECU's used different Torque Models for E. I'd rather have the car behave the same on 93 pump and on E.
Reply With Quote