mvvette97

iTrader: (18)

Have ported heads and cam with full boltons. With the wideband in the car it's about 12.9 to 13.1 at wide open. Is this about right? I hope so because I have no idea how to change it.

RedsrtAk

iTrader: (9)

main mods are in my sig.....using EFI live as well

Im at 12.7-12.8 at WOT....seemed like it pulled the best there off the spray. Yours sounds about right(I would run a tad richer imho)....but everyone has different opinions.

mvvette97

iTrader: (18)

yea i was kinda thinking the same thing. Do you know what I need to change to get the AFR down some just a full throttle? There is alot I don't know about EFI Live yet.

SSAUTOCHROME

iTrader: (2)

13.0 is best for power in an LS1 bro., leave it alone.

Gh0st

iTrader: (3)

Way to make things up

SSAUTOCHROME

iTrader: (2)

FEEL BETTER NOW, Gh0st?

HP TUNERS RECOMMEND:

9.0:1 BLACK SMOKE (NO POWER)

11.5:1 RICH BEST TORQUE @ WOT

12.2:1 SAFE BEST POWER @ WOT

13.3:1 LEAN BEST TORQUE @ WOT

14.6:1 STOCHIMETRIC AFR ( CHEMICALLY CORRECT )

15.5:1 LEAN CRUISE

16.5:1 BEST FUEL ECONOMY

18.0:1 CARBURETED LEAN LIMIT

22.0:1 EFI LEAN LIMIT

trev0006

Thanks

chpmnsws6

iTrader: (70)

Wrong

The best AFR is the leanest you can run with the most timing on the fuel you are running without any detonation.

YellowToy/A

iTrader: (1)

If you run that a/f ratio I hope you make it richer when it gets hot. Is a few horse power worth it for a blown engine. how much horse power do u gain going from 12.7 to 13.0? 5? Lean is hotttt

mvvette97

iTrader: (18)

I don't have any spark knock logging with EFI Live. I would like to richen it up just a little but I don't know how.

DaveX

If your tune is correct and your not running a custom OS, all you need to do to change WOT AFR is modify B3618. If it reads in Lambda, you can change it to AFR under edit, properties, then restart EFI Live. This table will change your commanded AFR for WOT. From there you just need to make sure actual is following commanded. If it doesn't then it is tuned differently then what I understand "correct" to be. Nobody can tell you what your optimal AFR and timing will be for your combo. Dyno or the track and some experimenting are the only way to find out.

mvvette97

iTrader: (18)

I do have a custom tune. My commanded AFR is set at 11.7 but it's leaner than that. I mean it runs perfect just driving but I just thought it may be a little lean for safety.

LS1-450

iTrader: (33)

Are you saying your car is tuned w/EFI Live, owned by someone else or are you saying that you don't know how to log knock w/ your EFI Live software?

If you have the software, we can explain how to log knock. Just let us know.

LS1-450

iTrader: (33)

+1...

Gh0st

iTrader: (3)

Theoretical != actual

Please let the people with experience comment here and keep your uneducated nonsense out of here

mvvette97

iTrader: (18)

Yes the car is professionally tuned with EFI Live. While logging the car I have no spark knock. I guess what I'm tryin to say is that I assume it's not real lean because I don't have any spark knock.

LS1-450

iTrader: (33)

Ok, thanks for clearing that up. Unless she's running hot, there doesn't seem to be an issue. The best test may be to log some WOT runs on a 90-100*F day. Mine doesn't knock @ 13.0:1 on hot days running 8.54 DCR, 24.5 degrees of timing from 5200 to 6400 RPM, moving 430+ g/s of air through the combustion chambers (est. 288-291 CFM per intake runner), & having an ambient cold air feed (colder than normal under hood feed temps.). Hope this reference info is helpful. Although, it is just a reference.

Having said all of that; I don't disagree with the comments suggesting that mid to high 12's:1 is a safer A/F ratio.

mvvette97

iTrader: (18)

So then running too lean should cause some spark knock? I have logged it many times and don't have any knock to speak of. One day when it was really hot I managed to get .1 of knock retard but that happened down low in the rpm range. I assumed since I don't have much if any knock then it must be about right. I know too much timing and too lean will both cause it. Since I'm good with knock I should be ok then?

LS1-450

iTrader: (33)

Yah, that's what I was trying to convey, but, with supporting info. Just stick w/ high octane fuel for WOT & anytime you're gonna make prolonged, consecutive WOT runs (like for road course driving), make sure you log knock because the elevated oil temps are gonna cause the engine to be hotter than during street driving or even @ the drag strip.

SSpdDmon

iTrader: (10)

Personally, I recommend 12.7:1 for N.A. AFR. That's where I've made the best power on my setups (I'm less than 1,000ft above sea level). That combined with about 27* of timing. This was on a 241 H/C car with a 23x/23x ~.600 lift cam.