100 over sticks, How much PW?

[GMC_2002_Dmax]

What I have found is that overfueling a dmax makes for better power at WOT as long as rail psi is held.

Ed Wayne and I spent a lot of time with his truck at the track and we bantered back and forth whether or not the extra fuel was necessary.

In the end more was better.



My advice is to let your SOTP meter and the track times dictate your pulse width choice, don't use an arbitrary number.

Also the psi drop is greater the bigger you go because when the injector opens you lose a lot of psi at the nozzle, it may seem wrong that you have to add pulse width at lower psi/mm3 but it is usually the case.

I looked up the tune file for a twinned LLY I tuned in Canada with SoCal 100% sticks, the pw ranges from 1860us to 2470us on the smaller tunes, the bigger tunes have 2800-3100us and it may or may not be overfueled, but it sure does run.........:thumb:, also with two completely stock LBZ pumps there is no problem maintaining 26K+ rail psi.

I would suggest starting at 1800-2000us at WOT and see how it does.

Good Luck

 

[TrentNell]

Like i said I would run 2200 , honestly I would keep adding pulse from 1800 untill it either slows down or no longer can hold rail , JMOP I know Dimitri has ran 2800 with his 100% overs , and in dyno form has ran 3100 :baby: Have know clue how it held rail pressure though , but def made plenty of power on the dyno

My advice is to let your SOTP meter and the track times dictate your pulse width choice, don't use an arbitrary number.

Also the psi drop is greater the bigger you go because when the injector opens you lose a lot of psi at the nozzle, it may seem wrong that you have to add pulse width at lower psi/mm3 but it is usually the case.

I looked up the tune file for a twinned LLY I tuned in Canada with SoCal 100% sticks, the pw ranges from 1860us to 2470us on the smaller tunes, the bigger tunes have 2800-3100us and it may or may not be overfueled, but it sure does run.........:thumb:, also with two completely stock LBZ pumps there is no problem maintaining 26K+ rail psi.

I would suggest starting at 1800-2000us at WOT and see how it does.

Good Luck

I like your answer Tony

 

[sweetdiesel]

Thanks for the input Tony not sure I'm looking for 800hp just a basic starting point and clean running tune would be fine with me

I would of never thought of going to the 3000 ish area but good to know others are

 

[MMLMM]

Just tuned a freshly built LB7 last night with a new set of 100 overs to get it drivable. Went 1889mS in the bottom. Timing 22-26° seem to run pretty good on the street, although this is a single cp3 truck, and a big turbo right now. Dual fuelers are on the way and we will play again.

 

[wikdlmm]

What did you do with the 40 overs Simon?

 

[03 D-max]

its threads like these that make me want summer back so i can start maxeffort tuning the new parts on my truck :thumb: goodluck simon I'm sure she will run like hell

 

[03 D-max]

What did you do with the 40 overs Simon?

http://www.duramaxdiesels.com/forum/showthread.php?t=16149

 

[IdahoRob]

Every set of injectors are different even if they all came from the same place and labeled the same %. You'll need to play, as John pointed out, wide varibles between sets and pumps. I like pressure. Add pulse width until your pressure starts dropping and you are then close to max effort.

 

[sweetdiesel]

Every set of injectors are different even if they all came from the same place and labeled the same %. You'll need to play, as John pointed out, wide varibles between sets and pumps. I like pressure. Add pulse width until your pressure starts dropping and you are then close to max effort.

That being said alot of trucks are even slightly different from what I've seen

when you say you like pressure do you mean down low?
To be quite honest I don't change alot in my tunes I only add pw in the wot area at high pressure this is what got me a little worried about big sticks

Abby tune right now is actually reduced x 10% except wot area
I'm not to worried about it since it's a lb7 and they seem to take to tuning very easy


Appriciate all the replys

 

[LarryJewell]

not sure, but do you need to take into consideration your custom fuel plumbing as well, I would think the larger volume your fuel lines are supplying will have some effects on the final outcome.

 

[SmokeShow]

subscribed. good reading gents! :thumb: