Lets discuss AFR

LaserSVT

LaserSVT

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So I just got done with my new wideband install and just did some idle testing to make sure its functioning. The tuner will be working his majic on Tuesday but after that I would like to tweek it for normal driving. He will have it great for loaded and WOT AFR but I may want to lean it here and there for around town driving. So what target should I set. I figured I was gonna shoot for an off boost AFR of 14.7 give or take.
I am about to go see where shes at at WOT in a few minutes right now but its not really gonna matter since the cars tune is set for 16psi and now all I see is 8.
 
all i see is 8 psi! like thats a bad thing! oh, all i have is a super charger waaaaa waaaaa waaaaaa lol!
 
Lick my taint cock bite. :p

No sad faces up there, only questions dick weed. BUT I am a tad bummed the boost dropped so much. :lol:
 
well would you rather less boost and safer engine or more boost and a hole in the oil pan from the crank? 8 psi if perfect for now, until you can build a forged rotating assembly. i alreadyhave a block that will eventually be the new motor, but the new motor will have 5.4 liter c-heads on it and be forged internally.
 
Your tuner will be setting up open loop for WOT. The computer and the O2 sensors (adaptive learning) will take care of closed loop (assuming that your MAF function and injector data are correct), so you probably won't need to worry about it.
 
Great. So that was a waste of $170. I guess the only thing it will be good for is to tell me if my fuel system fails and goes lean under boost?
 
BTW right now its about 14.4-14.8 on normal cruising around and idle. At WOT it goes to 10 and maybe lower as it stays at 10 even for the whole run so I think thats my sensors limits. But at least that tells me there will be a nice power gain just pulling that excessive fuel out much less the 5-8* more timing we can throw at it. :wrench
 
Yeah, we will be bringing that up to 12.2-12.5 for WOT. :)
 
Thats still rich. 14.5ish is perfect number and thats about what I am at while just cruising and thats kinda what I would shhot for on a NA stup but with my blower level then mis 12's is about perfect.
 
kustomizingkid said:
10 a WOT is on the rich side... but it is safe, and safe is always better...
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safer, no. 10 and richer you run the chance of washing the cylinders.

i usually tune for about 13-13.5 for part throttle acceleration off boost. idle is up to the car, some cars like to run lean, some car like to be rich. and you can usually get cruise to about 15.5 or so and have no problems at all.

but laser, what hardware/software are you using to tune the car?
 
bryantaylor said:
safer, no. 10 and richer you run the chance of washing the cylinders.

i usually tune for about 13-13.5 for part throttle acceleration off boost. idle is up to the car, some cars like to run lean, some car like to be rich. and you can usually get cruise to about 15.5 or so and have no problems at all.

but laser, what hardware/software are you using to tune the car?
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I don't think 10 will wash cylinders... but I will say it isn't even close to ideal.
 
LaserSVT said:
Great. So that was a waste of $170. I guess the only thing it will be good for is to tell me if my fuel system fails and goes lean under boost?
Click to expand...

It is a gauge like any other, and far from a waste of money! AFR is one of the best things to monitor on a boosted car.

kustomizingkid said:
I don't think 10 will wash cylinders... but I will say it isn't even close to ideal.
Click to expand...

10:1 is pig rich, and can start causing issues. 12:1 or so would be much better.
 
FWIW, I have a wideband on my '93. I've noticed on the street most of the time cruising gives pretty close to stoic values of 14.x. Part throttle under load will show 12s and sometimes 11s.

Since I haven't permanently mounted the display yet, I don't really know what the AFR is at WOT since the display flies off the dash. LOL :D

I'm still working on wiring auxiliary sensors to be able to datalog before I permanently mount the display.
 
Oh yeah, 10 is pig rich and will be fixed soon here. Seems the car is already doing a dandy job keeping it stoich under normal cruising so I aint woried. After Tuesday things should be pretty groovy.
 
Playing with fire can be dangerous to your health. The last thing I would recommend is fooling around with a tuners tables, especially a reputable one as more than likely he has worked out all the fat spots during the drive cycle. JMHO
 
Roadboss said:
Playing with fire can be dangerous to your health. The last thing I would recommend is fooling around with a tuners tables, especially a reputable one as more than likely he has worked out all the fat spots during the drive cycle. JMHO
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I hear ya mang. What DLF said made perfect sense and I know my tuner REALLY knows these engines he just dont normally mate them to an auto and hates working on that part.
I have my trans tune down and hes gonna work off my file. I will leave his engine file alone as I can see the car is running at perfection during normal driving as far as AF goes. My IATs are down a whole bunch too so I really look foreward to his majic on Tuesday.

My wideband will pretty much just warn me if I have a fuel system failure or let me know on hot days that there are issues and warn me to back out of it.

I will have him change a couple trans parts though. Before to be safe we had the car shifting at 5750 for the 1-2 and 2-3 shifts and at 5000 for the 3-4 shift. I am gonna add 350rpm to the 1-2 & 2-3 shifts and 1050 to the 3-4 shifts at WOT.
 
LaserSVT said:
I will have him change a couple trans parts though. Before to be safe we had the car shifting at 5750 for the 1-2 and 2-3 shifts and at 5000 for the 3-4 shift. I am gonna add 350rpm to the 1-2 & 2-3 shifts and 1050 to the 3-4 shifts at WOT.
Click to expand...

I have the WOT shift points for the 1-2 at 6300 and the 2-3 at 6450 commanded! :eek:

The 3-4 at WOT pretty much will not happen as it is set for 7000. LOL
 
slowmkviii said:
Is 5750 your command to shift or what you are actually
Shifting at
Click to expand...
It is what I am actually shifting at. IDK what the command is as I lost my software when my hard drive crashed. Gotta go buy a new Pro Package.
 
driller said:
I have the WOT shift points for the 1-2 at 6300 and the 2-3 at 6450 commanded! :eek:

The 3-4 at WOT pretty much will not happen as it is set for 7000. LOL
Click to expand...
I wonder if I can safely go that high? When all is said and done I will only have 50-60 more hp then you but 100+ more tq and I dont want to break the trans...... then again you race the hell out of yours and I dont even have drag radials.

Guess we will play around with it. :)
 
LaserSVT said:
..... then again you race the hell out of yours and I dont even have drag radials.

Guess we will play around with it. :)
Click to expand...

I'd go higher if the car wanted to but test runs at the track proved where the sweet spots were. It took many runs at the track to nail it down. First we worked at 200 rpm increments for each shift point then narrowed it down to 100 rpm steps. I may try again for plus/minus 50 rpm increments of where it is at now, just because I am anal about things.

I'd still like to datalog the car and see where it actually shifts at compared to the commanded rpms.

You'll never know except to run it at the track, thats what I know. The dyno curves will only put you in the ballpark. You could easily be leaving 3 tenths or more on the table with the wrong shift points and not even know it. ;)
 
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