Loudmouth LS1

iTrader: (10)

Ok, so I adjusted my timing for wot the way I was told, modify from cells .6 down to 1.2 for the rpm's you want, so from .6 down to 1.2 I subtracted 6 degrees from my 28 degrees stock timing from 2800 rpm to 8000 rpm. Well on the dyno last night trying to tune in my 150 shot now that I got my fuel pump in. Well first off she was running way rich with the pump in there now, o2's were 990/1000!!! So I gotta get that tuned in sunday at the track (didn't have much time to screw with it on the dyno (they were rushing me, did two pulls, first one saw that, took out 4% fuel at wot and it didn't really change the o2's much, but gained 20 rwhp). But anyways, I was just looking at my logs and for some reason the timing held perfect at 21.5 degrees all the way till about 6600 rpm, then it started rising and at like 7000ish I saw 30 degrees (that may have been right as we were letting off, cuz I had the shift light at 7000 to stop at) but even before the 30, I saw like 25 and change. So what did I do wrong that caused the timing to go up there? Any ideas would be greatly appreciated, thanks! Cuz that really freaked me out, i'm running almost 11.5:1 compression on 93 octane with the 150, so the timing going up isn't a comfortable thing for me, hehe, yet there was no knock!

HumpinSS

iTrader: (1)

1. send a log and
2 sned the tune

HumpinSS

iTrader: (1)

Do you have a fast 90/90. did you remove the big solenoid located forwards to the manifold and disconect it...

Loudmouth LS1

iTrader: (10)

Don't know if I can, can't really get it off the laptop, no disk drive. I'll see if I can get the laptop online though tomorrow maybe.

I'll tell you this though, I didn't have an issue when I had subtracted timing from the entire table, but then I put the table back to stock and took the 6 degrees out just from wot where I was told to take it out for wot, so I was wondering if there's a cell that I missed or something or was misinformed?

Loudmouth LS1

iTrader: (10)

Nope, on a ls6 intake and stock ported throttle body.

2xLS1

iTrader: (25)

Look at the histogram. Most times at really high rpms you will see the airflow backing up into lower air flow cells. Pull some timing in the .52 and .56 cells at the higher rpms where you are seeing the timing increase.

Loudmouth LS1

iTrader: (10)

What is the histogram? And you mean take some timing out where i'm seeing it added at the higher rpm's in those cells? I appreciate the help, don't wanna grenade my new motor cuz of a stupid mistake!!!

2xLS1

iTrader: (25)

I don't know what scanner you are using but HPT has a chart called a histogram to view scanned data. This is what I typically see for airflow durring a WOT run on a N/A car. You can see where the airflow starts backing up at higher rpms.

Loudmouth LS1

iTrader: (10)

I use autotap and ls1edit to do my logging and tuning. That graph is pretty cool. I'll make the changes in the program for .52 and .56 before I drop the new program in tomorrow. What should I do, set them to 22 or subtract 6 degrees, i'm assuming set to 22 since those numbers are a bit higher than the .6 and down were to start with, right?

2xLS1

iTrader: (25)

I'd set them at what you want the timing to be at those rpms.

Loudmouth LS1

iTrader: (10)

Cool, thanks for all the help man! That's what I did, and I just dropped the tune in, gonna go out and test her out now, i'll let you know how it goes.

jimmyblue

iTrader: (11)

As your breathing fades so will your dynamic cylinder
air number, indexing you to a higher advance row in
the table if you left the profile the same, and only
scaled it. This is not necessarily a problem, it may
be quite appropriate given the reducing cylinder
charge and the shorter time left to burn it in.

Loudmouth LS1

iTrader: (10)

Um, I hate to admit it, but i'm not really sure what you mean.

Loudmouth LS1

iTrader: (10)

Ok, so I took it out to test it after leaning out my part throttle by 3% (was averaging -9.xx) and leaning out my wot 8% (was running really rich even on motor, like 950's/960's) and changing the numbers in those tables for the timing and did a second gear pop all the way to 7200 and the timing held 21.5 the whole way through, so that's fixed (thank you)!!!

But I have another issue. The 8% put me perfect at wot, now i'm gettin 895 - 905 on the o2's all the way through!!! But the 3% leaned me out a little on the part throttle a little (now averaging -7.xx), but something's weird. When I recorded my wot's and went and looked at them, lterms were locking at 0 when it was in fuel trim cell 22, but at higher rpms it was switching to fuel trim cell 15 and then the lterms were not locking at 0, they were like +.8 and +1.6 or something like that, so what do I need to do to solve that, and how come it switches to fuel trim cell 15 sometimes, never used to do that on my stock motor, but since I put the new motor in, i've been noticing it doin that?

Phoenix 5.7

iTrader: (7)

im guessing this is all with a NB O2? an WB O2 would be a worthwhile investment

Loudmouth LS1

iTrader: (10)

NB O2? What's that? And I have a problem with getting a reading on a wideband on the dyno cuz of my exhaust, or at least that's what they tell me. They're not getting an accurate reading, they say it's cuz I have almost no exhaust, i'm running like 20 inch extensions off my collectors and that's all. So is that true what they're tellin me? Cuz if not, I need to go to a different dyno, cuz i'd really like to get an accurate A/F instead of relying on tuning off my o2's!

2xLS1

iTrader: (25)

NB = Narrow Band. What are you doing to lean out part throttle? That should be closed loop 14.7:1 controled by O2 feedback.

Loudmouth LS1

iTrader: (10)

I tune my part throttle with the ifr table, that's how i've always been told to do it, and I get the average by driving around for 15 minutes and taking the average of the lterms in fuel trim cells 6 to 14, is that correct?

2xLS1

iTrader: (25)

IMO, the IFR table should be set for the size injectors and then left alone. The general consensus is to get you LTFTs in line by changing the VE table. Also, you mention average O2 readings at part throttle. O2s at part throttle will be constantly switching between 0 and 1 volt so any reading at part throttle would probably be meaningless.

Loudmouth LS1

iTrader: (10)

I was always told not to screw with the ve table, that it could mess stuff up! I mean, i'm not the best and still pretty new with tuning, just what I was told by people when I started doing my tuning. And when I said average, I was talking about the lterms, not the o2's. This is getting involved, maybe I should just pay a professional to tune it now, cuz i'd really hate to blow my motor and the tune is gonna have to be perfect with how much nitrous i'll be using!