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Trim relearn question

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Prd2010

New member
My cars was already fueling perfectly. I just changed some non fueling parameters. Do my trims still need to relearn? This was a partial write using dhp. when I last programmed it ltfts were right where I needed them from the start. I waited my hour drive time and four starts for wot run. I'm just thinking if I haven't changed any fuel parameters can I go wot from the beginning with no worries?
 


Why not just drive it and find out?

If nothing changed fuel wise, nothing should change at all.

HP Tuners resets with the flash because it's flashing the whole file every time and I've never had an issue.
 
Good point lol. I have to wait a while until I can get back to my car. I was just seeing how others handled this sort of scenario. I figured a partial write it should be fine. I'm stock boost but pushing timing over stock quite a bit on this car. I may just wait 75 miles or so for good measure.
 
if you didnt change anything fuel related the trims will re learn and be the same as before. dhp seems to reset the fuel trims no matter full or partial flash.

so just drive it.
 
how much more timing? have you tuned the pe folder and such? hate to see ya run to lean with extra timing added.

id only add 2 degrees or less at a time. dont want it knocking to much all at once on ya.

you have a wide band installed? those tell you your true afr. kinda needed if your tuning wot.
 


No wideband for this car. It's been fueled and timed the same for over a month and a half now. Ever since it's been warm. It's a 97 buick riviera.
I started programming my bottom swapped 2004 gtp and noticed shift times stock were below .3 which is what I had the riv set at. So the only thing I changed was my 1 to 2 shift times.
I hit between 18 and 20 degrees depending on the day. Before i had it around 17 to 19 for like 2 months. Never any kr. The 1997 has a very flat mag curve so I manually raised it up as my Hz increased. I figured it's nothing too aggressive for a stock boosted car.
My gtp on the other hand is l 36. I'm having a pcv issue at the moment. Once I get that straightened out a plx wideband will be going where the egr was. Shooting to lower timing 1 to 2 degrees from stock in that car.
 
Maybe 4 degrees isnt quite a bit of timing as i first stated but it's seem to run around 15 from the beginning.
 
Prd2010 said:
Oh I haven't touched pe afr on the buick and wont.
Click to expand...

you really should touch it. pe stands for power enrichment, it sets your afr to a lower number making it richer as it needs to be really. then with the wb you can see if your matching whats commanded, if not you make a maf adjustment to make it match.

and the wide band goes in your down pipe pre cat, not in the egr hole. that wont work at all.
 
They run overly rich from the factory, if all he did was add a little bit of timing that's not going to lean it out much if any.

Factory is like 10.8-11.0 or richer if you are in the throttle long enough, it's just fine.
 


You are forgetting about the add vs rpm/time table that automatically reduces the commanded AFR.

DHP may call it something different but HP Tuners is add vs rpm/time. All supercharged cars are set to 12.4 in the main Base AFR vs ECT table.
 
I have no actual wideband experience yet. I swore I saw a post about using maybe it was the egr itself. Maybe that person has no idea what they are talking about like me lol.
I did leave the ae table stock also. So with the 12.2 commanded plus ae enrichment that does sound rich to me also.
The riviera only costs 500 dollars. I don't necessarily want to push it to where it just dies, but if it did my feeling wouldn't be too hurt.
I'll definitely be getting a wideband for the gtp though. I'll plug off that egr hole now then, that's good to know.
.
 


Fivefingerdeathpunch said:
You are forgetting about the add vs rpm/time table that automatically reduces the commanded AFR.

DHP may call it something different but HP Tuners is add vs rpm/time. All supercharged cars are set to 12.4 in the main Base AFR vs ECT table.
Click to expand...

you can add to that folder too if need be.

if you zero it out a maf adjustment will be needed up top. just learned that last month. as i ran out of fuel about the 1000 foot mark into a 1/4 mile pass.
 
Leave PE alone. They run rich enough stock. You don't have a wideband, so you are blindly adjusting it. Just keep it from getting kr, and you'll be fine.
 
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