LBZ Max Pulse Width on stock injectors.

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
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Lexington, Ky
Not true by any means... you can get 200% overs if your wanted them

From where, I'm pretty sure your not gonna be able to get them from the big companys with. Hell DDP had a hard time selling my brother a set of set 150 horse injecters because he had a stock turbo still. They didn't want anything to do with it at first
 

duramaximizer

#1 Abuse Enabler ;)
May 4, 2008
1,187
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Who's are the best? What are the best ones to buy. Extrude Hone or other way of modifying them. I know there were different angles and some different hole combinations.
 

Mike_S

OOPS!
Nov 18, 2009
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So now he's gonna have 100% oversized injectors AND a 4000uS pulse width...awesome! :banging: I can see some major grenadeage in this kids near future...:thumb:
 

Mike_S

OOPS!
Nov 18, 2009
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Just something for your friend, and perhaps you, to think about: at 4000 RPM, with a 4000 uS pulse width, your injectors are now open for a total of 96 crank angle degrees. I noticed that there was also mention of 4500 RPM...that same pulse width at 4500 now makes the injector-on degrees 108 at 4000uS. IIRC, peak cylinder pressure should occur at about 20-25 degrees after top center. leaving out ignition delay, rate of burn, cetane numbers etc for simplicity's sake...for peak pressure to occur anywhere near that point, baring all the other variables, you would have to set your timing advance at approximately 54 degrees! Now you are within the realm of injecting fuel when there is not sufficient heat to ignite it, you are most definitely hitting the cylinder walls with raw diesel, and lastly you're making your engine fight itself to make any power at all. If you were to pull the pulse width back to a more acceptable 3000-3250 pulse, you can now run timing that is WAY more sane, and actually make MORE power. :thumb:
 

JOHNBOY

< Rocking the Big Single!
Aug 30, 2006
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Just something for your friend, and perhaps you, to think about: at 4000 RPM, with a 4000 uS pulse width, your injectors are now open for a total of 96 crank angle degrees. I noticed that there was also mention of 4500 RPM...that same pulse width at 4500 now makes the injector-on degrees 108 at 4000uS. IIRC, peak cylinder pressure should occur at about 20-25 degrees after top center. leaving out ignition delay, rate of burn, cetane numbers etc for simplicity's sake...for peak pressure to occur anywhere near that point, baring all the other variables, you would have to set your timing advance at approximately 54 degrees! Now you are within the realm of injecting fuel when there is not sufficient heat to ignite it, you are most definitely hitting the cylinder walls with raw diesel, and lastly you're making your engine fight itself to make any power at all. If you were to pull the pulse width back to a more acceptable 3000-3250 pulse, you can now run timing that is WAY more sane, and actually make MORE power. :thumb:

If your pulse widths as big as 3000 you need bigger injectors!

I can not get anywhere near 3000us with my injectors. 2 CP3s will not keep up:D

Exergy has some damn nice bigguns.

I have never used Socals but have heard good things.

II now has a Bosch flow bench up and running. It has really help their injector program from what I have seen.
 

Mike_S

OOPS!
Nov 18, 2009
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If your pulse widths as big as 3000 you need bigger injectors!

Oh I agree with you, but for those who still don't have anything but stock, at least staying at or below the 3000 uS range will help things stay together while making respectable power. I managed 525 ish HP with a 3000 uS pulse, falling rail pressure, and a few hardware mods...:D
 

SSchmi5519

LLY Cult Leader
Oct 19, 2008
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Arizona
I like Exergy for injectors.

As far as 4000uS....:rolleyes:

I will guarantee that there is some limiting table that is keeping the actual pulse down on this truck. Either that or this motor is soon to pop.

To the OP:

Tell your friend to turn the pulse to 3200. He will gain power.
 

lb7blksmk

low n' black
Dec 30, 2009
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oh my god.. what is wrong with some people. youd think he would notice low fuel rail from clearing the smoke up... he should just stick to getting tunes built for him.
 

duramaximizer

#1 Abuse Enabler ;)
May 4, 2008
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Edgerton, Ohio
Some have a lot wrong ....people need to read. He is holding 29000psi from an Industrial Injection CP3.

The truck runs really well; for now. But it doesn't smoke at all. 36*timing; spins out hard pulling the sled in 4th gear with the converter locked and will blister 33" tires at 50mph on the road. :confused:
 

Subman

Old Geezer
Jun 27, 2008
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Sounds like his, "stock" injectors are about half what normal stock ones are if he's able to hold rail pressure at those high uS. As far as injectors larger than 100% Big Dipper can get you whatever you want. I just replaced a set of 130 over from Big Dipper with a set of 100 over from SoCal. The Socal injectors are very nice and I'm making somewhere in the 900-950hp range on 2450uS. Have a 260gph Fass and a two stock CP dual fueler and it holds well. The 130's were hoses, couldn't clean them up with my twin setup and I'm selling them to a puller, they should work fine for his application. Another source of very good big injectors is F-1, we have a monster set in Max'd Out, (he won't even tell us how big they are) and Rob is able to tune it well and clean them up with the turbo and twin cp setup we have on Max'd Out. As you tuners know, there is a huge advantage to tuning with larger injectors, (if you can hold rail pressure) do to the shorter pluse width and less timing you can use. Engines like that combo a lot better, especially in the big HP ranges.
 
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MMLMM

Tunergeek
Mar 2, 2008
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www.dyncal.com
4000uS and He is commanding and holding 200MPa (as in you actually have a log showing actual rail pressure of 200MPa? are you sure? LBZ tune right? Post it up please.
 
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