desired % of injection BTDC

[LLYD_MAX]

Im trying some new things on my truck tuning wise. Ive been making tunes for awhile now but nothing serious. Ive started using Josh H's timing calculator and its been a really big help but im still a noob none the less.

My question is what is the general amount of fuel people are dumping into the cylinder BTDC??

You would want about half or more of the fuel to be dumped BTDC right??

 

[SgtKilroy]

My guess would be that it has a lot to do with what RPM and how long the injector is actually open. The injector should open at the same speed, but the piston speed can vary. My question would be what's the rate of change as RPM increases. Assuming that the pulse width and pressure remain constant. I could also be completely off base.

 

[GMC_2002_Dmax]

When it rattles you went too far.

:thumb:

 

[LLYD_MAX]

When it rattles you went too far.

:thumb:

thanks for the tip

it has a little rattle to it now so im guessing i need to lower the PW and increase the fuel pressure in order to get more fuel into the cylinder faster without keeping the injectors open as long and chasing the cylinder with fuel.

 

[Bryce418]

When it rattles you went too far.

:thumb:

Damn Tony! Your giving out all the top secret stuff.

 

[THEFERMANATOR]

I run 60% on the top end, but I'm only running a 1950 PW on my tune. At cruise and part throttle I'm running well over 100% (around 5-7 at cruise).

 

[LLYD_MAX]

I run 60% on the top end, but I'm only running a 1950 PW on my tune. At cruise and part throttle I'm running well over 100% (around 5-7 at cruise).

When you say your running 1950 PW your referring to the bottm right corner of the table which is WOT and higer Rpm's right? Just trying to learn

I got to looking and at WOT at 3200rpms im only dumping 35% of my fuel BTDC

And at crusing speed it shows im dumping about 65%. as far as PW if im reading my table correctly im running 2030 is that to much for stock sticks and stock trans?

I know im asking alot questions that seem really dumb to most of you people on here but yall are 1000x smarter than me on this stuff but i just want to learn. Sure i could buy tunes from a commerical tuner but I like doing stuff myself so i have somthing to take pride in and be proud of when im done. I understand people dont like giving out their tuning info in the open forum but every little piece of advice and info i get i appreciate and use to my fullest advantage so i can learn and not ask as many dumb questions. :thumb:

 

[DIESELMAFIAPER.LB7]

I ran a 3250 on stock sticks an tran I limped it if I hit 5th though as for timing 29* timing with a 50/50 table

 

[Mike_S]

Im trying some new things on my truck tuning wise. Ive been making tunes for awhile now but nothing serious. Ive started using Josh H's timing calculator and its been a really big help but im still a noob none the less.

My question is what is the general amount of fuel people are dumping into the cylinder BTDC??

You would want about half or more of the fuel to be dumped BTDC right??

This all depends on what your end goal is. A max mileage tune will have a different timing table and require different amounts of advance than a race or pulling tune. What is it that youre after?