If you don't mind me asking, why set a QC 4x4 at 0714? I left mine at stock stoich. And mine is forged. Would I benefit from changing that?Originally Posted by rays04gtx
Also I have read that changing stoich doesn't make a difference due to narrowband o2 sensors and it will still go back to 14.7.
Im still trying to learn all this as much as possible and honestly curious.
the way i see it changing stoich would be changing the fa ratio that the sensors are looking for
that is just for part throttle tho
the trims have nothing to do with your mixture when yer dead in it
I don't mind at all,
I've found that a lot of the "heavier trucks", can benefit from the extra cooling, think about it, the Factory sets the 6.4 truck at .0720, but the 6.4SRT is set at .0688, we all know the SRT6.4 is going to see abuse, but it's mostly RPM varied no prolonged 1100-3000 usage, while the 6.4 truck is going to see more "load" in those ranges.
The two graph captures are from an 08 2500 series QC 4x2 , 5.7 with Eagle heads Comp 268H cam, the 1st graph is with a .0720 stoich, the 2nd one is the Stock.0694 stoich
Both graphs are High Temp average after a 35 min test drive, over the same roads with a 5k lbs loaded trailer , 2nd graph was cold start, then 1st drive , the 1st graph is after ".0720" tune was loaded and truck driven around 35 min.
this route we take has two 1/8 mile "test hit" spots both drives were able to take advantage on said spots....standing start, hard pull away from start to 60mph, shifting manually in Tow/haul....... almost every where you look on those graphs, the .0720Pe has colder temp averages, look at 1184-2986RPMs which is average RPM range for daily driving.
the .0720 is "warmer" @800-992 , but that's due to engine temp being high to start.
side benefit is the .0720 tune didn't pull any timing during parts where the trans should kick down but doesn't.
the other benefit on these heavy trucks with Eagle heads is, they are less likely to suffer from detonation if you have to run 8X octane gas.
One of tunes Ric(purple ram) has written for a dirt drag truck that we built, keep in mind the truck runs 200ft track, off the trailer then back on trailer till the next event..
the stoich is set @ .0813 ,with No RPM triggers to go "W.O.T" tables, Fueling or Spark.
62 Biscayne 425/409 SS/D stock class car 10.60s
66 Dart 426CIG3 8.60@171 2750lbs Naturally asperated
04 Ram All Alum , 468Ci G3 10.50s @4800 lbs Naturally asperated
04 Rumble Bee, built 6.1 ,4000lbs 10.48 @ 129s MPH. Naturally asperated
05 Rumble Stock 5.7, 3.92s TUNE ONLY 13.94@98mph
Correct , but how often are you dead in it with QC truck? the guys out in the open road parts of the country will hit W.O.T more often then 90% of the urban/suburbs owners ,most those guys will find W.O.T once, maybe twice a week.
62 Biscayne 425/409 SS/D stock class car 10.60s
66 Dart 426CIG3 8.60@171 2750lbs Naturally asperated
04 Ram All Alum , 468Ci G3 10.50s @4800 lbs Naturally asperated
04 Rumble Bee, built 6.1 ,4000lbs 10.48 @ 129s MPH. Naturally asperated
05 Rumble Stock 5.7, 3.92s TUNE ONLY 13.94@98mph
Totally makes sense to me. Just one thing I don't quite understand.. I was under the impression that during part throttle, changing stoich wouldnt affect anything due to it still targets 14.7 due to the narrowband o2 sensors.. Am I wrong there, or did I misunderstand what you are saying here..
Would it benifit me any to set mine to say 0700? Mine is forged with a 185 thermostat bigger aluminum radiator and it runs 180-185 during a 75-80 degree day. Iat is usually 10-15 above ambient.
I'm sure I'd have to start over with my ve tables, pe, and some others if I were to change stoich?
Thank you for educating me!
0700 is telling the system that the mixture is 'spot on' when its at 14.28
you divide the stoich number into 1 to find that
Understand that. I was referring to the post where he said he sets up forged eagle head engines at 0700 stoich. Mine currently is at the stock 0688 which comes to 14.53.
Like I mentioned before, I didn't think it would actually change much for part throttle due to narrowband o2 sensors.. I was under the impression it would still try to get back to 14.7 regardless. Even set at 0688 pt cruise is still target 14.7 and hovers 14.6-14.8 during cruise..
forget the number 14.7 for now
the sensors do not measure air to fuel ratio
they do not measure fuel to air ratio either
they only measure air, or the lack there of...
if you raise the stoich value in the pcm the system will be ok with sensor seeing less air
Understand, but where I get lost is what would change if I set stoich to 0700 from 0688? My wideband is reading in afr so 14.7, will it still read around that? If so then I'm still confused as to what is actually being affected by changing stoich..
I'm not trying to sound too stupid truly want to understand it. I understand most of this but this is where I get confused. Because if I'm still running 93 gasoline and not e85 or anything with a different stoich why would changing that number help?
aftermarket wideband has its own controller...
you are not changing anything in there.
if i were you i would stop using afr and start using lambda
I was planning on changing over to lambda on everything. I just need to remember the readings..
And switching to lambda makes me a bit more confused about all of this. Lol.
what is the "narrow band voltage for stoich that the pcm 'drives' to"???
(my scat front sensors produce a output of 0-5v)
So if I understand correctly it would still try to get back to the same narrow band voltage (14.7), if I change it. Essentially only affect wot and I would retune my ve and pe tables etc and end up the same as it currently is?
I think I understand it now..
i dont understand what spoolboy meant either
narrow band voltage is typically 0-1v
this thread has taken a turn for the better but needs a new title!
https://forum.hptuners.com/showthrea...724#post731724
Question. I have a 14 ram 1500 with the 6.4 I take. I look at my hp editor. I do not have the srv tables. Just a tab for enable or unable. How do I get those tables
Question. I have a 14 ram 1500 with the 6.4 Intake. I look at my hp editor. I do not have the srv tables. Just a tab for enable or disable. How do I get those tables
Try the beta editor. I put in a request to add the tables for my 2013 and they added it to the beta for me. If you don't see it submit a request and I'm sure they can add it for you.
It's not on the stable version.
I did contact hp. I sent them a tune file and the table I'd. So hopefully I'll have the tables soon. Thank you for the advice
No problem. They got it done in a few days for me. Good luck!
Have a question. I did the 6.4 truck intake swap with the 6.4 injectors. I ha e the the injectors dialed in perfect. On a cold start at least 40 degrees the engine misfires. I do have a wide band installed. Says I'm at about 1.4 lambda. After a few seconds the misfire clears up and idles down then I'm idling at 1.0 lambda. I k ow it's a way to lean. I've been trying to richen up the mixture. Just not 100% on wich tables to use. Obviously the tables I've been Messing with isn't working?
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