TT_Vert

iTrader: (12)

is there a threshold at which the LS1 motor doesnt like more timing? i added 2 deg. to my entire high octane table to see a max of about 30deg at 6k and it didnt really affect my et or mph any today. I also tried to modify my PE table and it didnt seem to affect et or mph. The o2 voltages went down as expected but had no effect on et. I went from .880s at WOT to .960s and everything in between w/ no change in et or mph. Very odd. Any input?

Feel free to check out my logs :
http://tech.cfbinc.com/dave/Logs/Track/
Thanks
dave

Slowhawk

iTrader: (12)

More timing doesn't always mean more power.I've had cars run there fastest times with 32 degree's and some at 24 degree's.What is the rest of your setup?

TT_Vert

iTrader: (12)

i have a 2000 c5 with long tube headers, 4.10s, vararam and bfg drag radials.

Dave

TT_Vert

iTrader: (12)

im usually seeing between 27-29deg WOT and i added 2 to this to see what would happen.
Dave

Slowhawk

iTrader: (12)

My 02 actually runs faster with 25 degree's of timing.The Vette's are very touchy in the timing tables.You have to mess around with torque management,KR noise level,and max torque tables to get the power out of them.I'm thinking you are getting KR and it's just pulling out the timing you put in.

TT_Vert

iTrader: (12)

check my logs, zero knock retard. what would torque management have to do w/ anything?
so you actually pull timing out of your car?

Dave

Team ZR-1

Being your injectors were running around 22 mSec pulse widths around 4500 and up RPMs the inectors are max'd out and making any changes to timing or PE is a mute point since the injectors are being forced to run static.
28 degrees max in true WOT is the best a LS1 needs if still stock engine compression.
Adjusting PE at higher RPMs will do nothing at all.

TT_Vert

iTrader: (12)

isnt 22ms at 4500 rpms only 82.5% duty cycle? I know the PE is doing something as my o2 voltages are changing so it is richening and leaning it out to some degree. is it possible that a car as stock as mine could be maxing the injectors? I know on my fords that ive exceeded 100% Inj. duty cycle w/o problems or leaning out. are the stock injectors no good after 85% IDC?
Dave

Colonel

"is it possible that a car as stock as mine could be maxing the injectors?"

Nope, not likely if all is working properly. And if adding fuel brought your O2s WAY up...well, I'd say you actually did add fuel. Stock injectors will do alot more than many people think. What kind of power are you making? Below ~440 RWHP?

Timing anywhere from 25-31 may or may not make a difference. It's a tricky thing. I've seen my own engines do better all the way to 31 degrees and I've seen 'em favor 26 or so. Just gotta play with it and see what seems to work best for you. I'm surprised you didn't see a loss at .960mv. There could have been other factors that effected testing.

patSS/00

iTrader: (6)

My stock injectors on stock engine would get to 100% duty cycle around mid-4K rpm also. This is a 2000 with the 26# injectors.

Slowhawk

iTrader: (12)

I also forgot weather/DA has alot to do with what you get.A hot/muggy day absolutely sucks for tuning.Most stock Vette's I tune run 24-26 degree's of timing.I'm still not sold on the maxing injector above 80% duty but TeamZR1 knows his stuff.

jimmyblue

iTrader: (11)

Perhaps you were already in the best place. The
880mV is close to where a lot of people run after
tune. Going fatter than 900mV (stock exhaust O2s)
may not help power (unless you were having a ping
problem).

Advancing timing similarly might only help after the
enrichment, if any enrichment were an improvement.
If you were within a couple of degrees of knock
threshold originally then you were probably pretty
well peaked up.

Did you try these fiddlings separately, or did you
try (say) a little more PE and then timing excursions
about that? The purpose of more timing would be to
position the burn pressure pulse, which would be
made slower by enrichment, to (or back to) ideal
in the delivered-crank-power sense.

TT_Vert

iTrader: (12)

Yes I did. first I richened it up (102%PE) and it didnt affect et or mph in at any part of the track, then i leaned it out (98%PE) thinking maybe I was going the wrong way (long tube headers skew o2 readings im sure). Then i went back to stock PE and added 2 deg of timing and it didnt affect anything either. Do you think i should have richened it up some and added the timing rather then just one or the other? I was just trying to do one thing at a time so i noticed any changes and what they did

Another thing i noticed looking at my logs is that im actually shifting closer to 6200. Im shifting on the stock tach at 6k, do you think i should try shifting at 5800 (approx. 6k actual??) Why dont i think of this stuff at the track

Dave

jimmyblue

iTrader: (11)

One other thing to consider / watch, is whether
the timing you add is showing up - or whether
you're running off the low octane table, or getting
pushed toward it by the knock learn function. If
you are (say) interpolated to 50/50 scaling between
the two on account of some knock history, then
the 2 degrees you add, may result in only 1 degree
of real applied advance increase (and maybe more
knock, sliding you down more, ....). For tuning
purposes I'd suggest copying high to low table
after making your changes, for purposes of test
runs and criticism, and then (for safety net
purposes) pull out 4 degrees from the low table
when you're done for the day. That way you know
that your word is law, and let KR (or better, the
live knock counts) indicate any timing excess.
Bearing in mind the inherent risk of too-aggressive
timing fiddling all at once.

As far as shifting, I'd say if your head hits the
steering wheel before the shift, shift sooner; if
your head hits the steering wheel after the
shift, shift later

TT_Vert

iTrader: (12)

i watched my logs and im seeing the timing I added. (between 30-30.5) That was the first thing I checked. What do you mean about hitting my head? are you referring to hitting the limiter?

Dave

jimmyblue

iTrader: (11)

I was just saying, if you feel the car "laying down"
before the shift, you might as well shift and if it's
still pulling hard, give it some more rope.

TT_Vert

iTrader: (12)

well it is still pulling when i shift, but the limiter is at 6200 and id rather not tag it. I "could" raise it,. but i assume that'd bend a few pushrods or screw something up..

Do you think i should have richened it up some and added the timing rather then just one or the other?

Dave

jimmyblue

iTrader: (11)

I think that would "complete the box" and let you
know if there is some synergistic bonus. There's
some chance of that (or the contrary, lean it out
a bit and leave alone or pull timing). If you keep
track of the "map" at least you'll know what made
any difference, and you can follow the arrow if
anything shows up.

TT_Vert

iTrader: (12)

keep track of the map? can you elaborate?? it varied from 14.1-14.2 max regardless of the max timing


thanks
dave

jimmyblue

iTrader: (11)

Like, fuel is north/south and spark is east/west;
keep track of the gain / loss from "center" and
you should see a contour, something to indicate
the direction of most sensitivity, which is what
you want to chase - most effect. Probably go
by trap speed if you are using the track, as the
"integral delivered HP".

Maybe make an Excel table w/ spark and PE as
the axes and trap speed as the value, just to
visualize? Right now you don't see anything
but as you build out, fill in more squares, it
should reveal that you're on some part of a
"hill", and in which direction lies the peak. If you
have the patience for it. Of course you may find
in the end that you were already good and have
only found ways to get worse... but you will know,
anyway.