Black Blown 02

1- Ok, got the 43lbers in. I started off with 5.42 IFR and had to work it down to 4.48 for slightly negative LTRIMS at idle. -1.6 to 0 is what I'm seeing. Cruising at anything above 35mph takes them to about -12.5, and when I roll into it a little (30% throttle) it goes to -9.4. Does thes seem normal?
2- If I understand correctly, I only need to worry about idle LTRIMS when adjusting IFR?
3- Is it time to start widebanding and adjusting PE vs RPM?
4- Maybe some quick pointers on PE RPM adjustments?

Thanks guys

XLR8NSS

iTrader: (4)

1. Yeah, the trims will fluctuate like that at different throttle positions. Shouldn't be a problem. Seems like bigger injectors do this more than the stockers.

2. That's the way I've always done it and haven't had any problems yet.(knocks on wood ) I don't think the computer looks at idle trims to determine WOT trims but, it always seems like if the idle trims are negative the rest are also. I think cruising trims are looked at to determine what to do for WOT. With yours negative everything should be fine.

3. You might want to drive your truck around for a day if your happy with the initial adjustments. I would do this just to make sure that the computer has had a chance to adjust for all different driving conditions. This probably is not necessary since the computer adjust SO FAST but, wouldn't hurt. If your ltrims at WOT are locked at 0% than you can start adjusting the PE table. Just do a very quick WOT blast to check the Ltrims since you don't know what the A/F ratio will be. Can you have the FJO and EASE hooked up at the same time?? That would be the best deal.

4. Just make small adjustments if your trying to lean out the A/F ratio. If you're lean to begin with make larger adjustments and sneak back up from there. I've never noticed a direct correlation between PE and the O2 readings. I've always just went with 5%-10%(105%-95%/110%-90% in edit) initial adjustments and then fine tuned from there.

Best thing to do is sneak up on the tune. It will probably take quite a few EDIT/EASE/FJO sessions which can be frustrating but, it'll be worth it.

Good luck man!

BigTex

iTrader: (16)

I think that you should tune for part throttle driving to get slightly negative Ltrims, then do some logging and make MAF adjustments to level out your idle and other rpm ranges that are out of line. Look at Chris B's LS1 Edit tuning guide for a basic overview and research MAF adjustments in the tuning section.

Black Blown 02

XLR8NSS- so my ltrims at WOT have to be at 0 to start pe rpm tuning? I haven't tested WOT yet, but what if they are a little negative? Thats okay right? Just as long as they're not positive?
BIG TEX- I heard you're not supposed to mess with the MAF stuff unless you absolutely have to. Straighten me out if i'm wrong.

parish8

iTrader: (6)

i am with xlr8nss but am definately no expert. when i did mine i didn't even really look at when my part throttle ltrims were where, i just wanted them to be mostly negative and by adjusting the injector flow was able to get them in the 0 to -12 or so range. sounds like big tex is shooting for something a little more acurate on the ltrims, is there some benifit to having the ltrims closer to 0 than what john and i did?

the reason you try to get your ltrims slightly negative is so that they go to 0 when you go WOT, they wont go negative at WOT but they will go positive if your ltrims are positive and that means the computer will be fighting you when you are trying to make WOT adjustments.

Black Blown 02

OK, mine are neg all the time so far, so when I go WOT they will probably go to 0? If thats the case, then that clears it up for me.
In the pe rpm table I see multipliers scaled across the board according to rpm. Can I look at the wideband logs, and adjust the tables by percentages according to the rpm that needs tweaking?

parish8

iTrader: (6)

yep, sounds like it is time for a short WOT log! get out there and do it, then report back!

i want to know what one of those ATI's with a stall and some traction can do!

Black Blown 02

I'll go get on it!

XLR8NSS

iTrader: (4)

Yeah, you can adjust the trims with the MAF but, I don't really like that method. If the computer is compensating with the trims and there is still room for more adjustment I wouldn't mess with the MAF.

I have used the MAF method to adjust trims in the past and the truck didn't drive right at all(transmission acted wierd) compared to using just the IFR.

The way I've heard it explained is that if you have a stock MAF you should not mess with the calibration.(makes sense IMHO)

Let us know how your test runs go.

Black Blown 02

Did some wideband logs. Worked my way up short wot bursts, everything was fine a/f was at 10.5-11to1 until about 4200 rpm in 3rd gear where it shot to 14.5-1 suddenly. I immediately got out of it. It was fine in 1st and second though. Kinda scared to try it again for fear of damage.I think I'll have to sleep on this one. Any ideas?