I'm actually pulling my motor and doing a full build, ST, head, etc - so I have no plans to sell in the immediate future and can wait for this to be released. Will be nice to not switch maps, measure, etc, and just drive. I have plenty of E85 near me.
N54 Stock DME Flex Fuel
- Thread starter Jake@MHD
- Start date
I'm actually pulling my motor and doing a full build, ST, head, etc - so I have no plans to sell in the immediate future and can wait for this to be released. Will be nice to not switch maps, measure, etc, and just drive. I have plenty of E85 near me.
At the end of the day the message is the same. Not gonna spend the extra time on here to figure out the best way to avoid offending everyone so I'm fine with moderate amounts of criticism.
I agree that it'll be wonderful to have. I think it's silly and mildy frightening how much the content of ethanol can vary at the pump and really wish this was out like 3 years ago. Plus no one's wife really wants to sit at the pump while their husband is flashing a map to accommodate for what's now in their tank lol.
Yes but would you trust that assumption? Given that you can fuck up your estimate of whats in the tank vs how much you put in vs what the station says it is...? What you thought was e50 quickly becomes "eFuck all" and i know the DME logic affords us a decent safety margin but thats a lot of timing and fuel to make up for.
I've done over 2 years without a problem. Clean logs with every check, and never any driving issues. Just don't tune to the edge trying to break records, leave some headroom.
I want FF, just for the times when I'm in BFE and only have access to 91. But I'm comfortable with my e85 tune.
I want FF, just for the times when I'm in BFE and only have access to 91. But I'm comfortable with my e85 tune.
If I recall Martial says the same about the the e tunes, which I own, but that doesn't totally convince me either.
I used to see the GM SUV' with the flex fuel badge on the tailgate some years ago when it started to flow toward the east. There was an article about a Tahoe or suburban, don't remember, on a field trip they were doing to see were the benifit was running 93 one way, and 93 the other. Of course the issue was the availability of pumps, the other was consumption. What I'm getting at is, other than switching fuels, there was nothing else that was altered for the two. So, if the ecu can detect misfires from low octane, and adjust it's knock, why wouldn't this do the same? Is there that much in tuning, that you have to tell it the fuel is different? There must be guys that tune the LS motors here, is this something that even needs a tune to be optimal? The reason I say this is, I run it na, also when I'm done with the nitrous, it runs better with e85, smoother, it cleans up at idle, and with the higher compression of these, it's well worth it.
How many times does the motor knock before that knock is detected, identified, and corrected? And how much correction is made?
The knocks it gets, even if it's just one before correction, are too many. And if it is corrected, it's more than likely over-corrected.
The knocks it gets, even if it's just one before correction, are too many. And if it is corrected, it's more than likely over-corrected.
I was just refering to the flex fuel capibilies of that particular vehicle and how it's adjusts to the fueling properties. This should be the same on evey vehical that's flex fuel ready unless it looks for octane factor. I'm no tuner by any means, been a truck mechanic for years, I new of a station not far from me so I'm going to run it with turbos when the motor goes in, nitrous is happy with it.
"knock," a generic term for any improper ignition sequence, is actually very common on most internal combustion engines. And as compression ratios and specific outputs climb, knock regularity will also climb. As ECU's advance with rising DCR's, they'll be more capable of accurately detecting and correcting said knock, but the correction will still occur post knock event, and will likely still over correct.
ALL internal combustion engines Knock and Ping to an extent. It's the nature of the beast. But audible knock due to pre-ignition an etc. Should not really happen on Modern day ECU's since they reduce individual ignition advance the in real time on the next firing sequence. If it registers again it increases the amount of timing pulled.
There are tables that the DME references how much timing to retard per Registered knock event. Which can be adjusted. I've done it on my car. Depending on the RPM it will pull anywhere from 1*-4* per knock event.
Since we're talking about knock, how effective is spark plug reading on N54s? Because I have trim pots wired into my knock sensors old school style.
So much false knock on the built motor had the DME going nuts but everything's gucci now that I filtered the signal.
I've ran it at 30+ psi and about 12* timing on E85 and no hiccups, but I was definitely diligently looking over each spark plug the next time I pulled them
So much false knock on the built motor had the DME going nuts but everything's gucci now that I filtered the signal.
I've ran it at 30+ psi and about 12* timing on E85 and no hiccups, but I was definitely diligently looking over each spark plug the next time I pulled them
I understand the freely-distributed Spaxxx tunes have reduced knock sensitivity. Does that mean a stronger knock signal is needed to pull timing, or the same knock signal pulls less timing?
Based on my experience, before using Spaxxx tunes my timing would initially pull 3* during a ping event then recover. Now with Spaxxx it pulls just 1.8*.
(I’ve been running these Spaxxx tunes with my own mods to them, 93 and up to E60 for two years no issues, btw)
yup. exactly why people should not do it without properly testing the individual engine. NO ONE!! to my knowledge actually used proper equipment to determine when or how hard an enine was knocking to differentiate false knock from real. As soon as the tables became available people started making blind adjustments to get rid of corrections. No bueno.
Now if someone actually did the proper testing for an individual engine to adjust the knock tables. then fine. But guaranteed 98% of the people if not 100% did not yet they are turning knock sensitivity down.
