does anyone know what the highest number on the injection timing chart for an lb7 is? is it around 30? or can i go higher....and were in the best place to increase the numbers? the top right or the bottom right?? any help would be appriciated

you would be better offposting thisin the EFI Live thread

Higher timing isnt necessarily a good thing.

moved

Search for the timing calculator v3 (it's on here somewhere), and play around with that. I have had good luck from 45 - 55% BTDC, depending on what I want from the tune. Around 45% BTDC appears to give better WOT economy for smaller pulsewidths (<2000uS) at the expense of higher EGTs. I usually stick to 50% (I am only running ~2200 uS), and it seems to work pretty well, and EGTs stay below 1300 most of the time.

Timing has one of the largest effects on this engine, IMO. It takes a lot of playing around to get the hang of it. Try downloading some tunes from the library and seeing how they do the timing vs. pulsewidth. I learned a lot that way.


Oh, and x2 on what Tom said: high timing isn't always better

does anyone know what the highest number on the injection timing chart for an lb7 is? is it around 30? or can i go higher....and were in the best place to increase the numbers? the top right or the bottom right?? any help would be appriciated

Our '02 made max power with 28 in the lower right, your results may vary...

Search for the timing calculator v3 (it's on here somewhere), and play around with that. I have had good luck from 45 - 55% BTDC, depending on what I want from the tune. Around 45% BTDC appears to give better WOT economy for smaller pulsewidths (<2000uS) at the expense of higher EGTs. I usually stick to 50% (I am only running ~2200 uS), and it seems to work pretty well, and EGTs stay below 1300 most of the time.

Timing has one of the largest effects on this engine, IMO. It takes a lot of playing around to get the hang of it. Try downloading some tunes from the library and seeing how they do the timing vs. pulsewidth. I learned a lot that way.

Solid advice...

Our '02 made max power with 28 in the lower right, your results may vary...



Solid advice...

At what Pulsewidth? Keep in mind the timing degrees is affected by the larger pulse width. The long the Pulsewidth the more timing you need to centralize the injection. Running 28 degrees on a stuck fuel table would not be a good idea.

Our '02 made max power with 28 in the lower right, your results may vary...

At what Pulsewidth? Keep in mind the timing degrees is affected by the larger pulse width. The long the Pulsewidth the more timing you need to centralize the injection. Running 28 degrees on a stuck fuel table would not be a good idea.

At "race tune" pulsewidth, not stock;)

I figured as much... but again you have to remember that judging by your tight lips around max power I would also assume you have the injectors done... this again greatly affects the timing.

Just making sure someone starting out with EFI Live does not go and change their stock fueling (or close to) tune. :)

I figured as much... but again you have to remember that judging by your tight lips around max power I would also assume you have the injectors done... this again greatly affects the timing.

Just making sure someone starting out with EFI Live does not go and change their stock fueling (or close to) tune. :)

I'm sure you remember what happens when you assume;)

Pulse width for a race tune is common knowledge these days...489rwhp/1010 tq on a Superflow is what McRat made 3 or 4 years ago with our CA Emissions truck...Oh, stock injectors...

I posted a tow/economy tune a few years back that has conservative pulse width and timing:)

I posted a tow/economy tune a few years back that has conservative pulse width and timing:)
That is a good tune to look at for beginners. Actually, my tuning was based on that econ tune for over a year. Probably the best tune in the library, IMO.