Injector size 100-200%

quinton

Active member
Nov 28, 2011
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36
Granbury Tx.
My 80 over nozzles on stock body are are smokey as crap no matter what. I can drive it but no romping on it anything over 1/4 throttle. Even at idle it hazes black smoke. Ive tried everything in the tuning to low pulse to high timing to low fuel pressure and high fuel pressure. It's just the nature of the beast I guess lol. But they sure do get down at full throttle! Like CaptPhil said mine is smokey as crap until about 15 psi of boost if over 1/4 throttle and embarrassing thing to pass someone, pull into traffic, or any little aggressive driving on the street. At night I've forgotten about it before passing someone and when I get around them I don't even see there headlights sometimes. Now I get a nice long running start so I can smoothly get into the throttle without excessive smoke. But setup does make a difference to. I have stock cam and stock heads with low compression. Winters I can't start the truck without plugging it in and I'm in Texas. Lol. Anything under 34* it won't start.
 

gmduramax

Shits broke
Jun 12, 2008
4,081
252
83
Nor cal
I daily drive on 250% overs. I can see a haze at idle and excelerating from a stop at night with headlights behind but it isn't a problem.
 

DIESELMAFIAPER.LB7

<----new hotness
Jan 17, 2010
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idaho
shop.dieselmafiaperformance.com
My 80 over nozzles on stock body are are smokey as crap no matter what. I can drive it but no romping on it anything over 1/4 throttle. Even at idle it hazes black smoke. Ive tried everything in the tuning to low pulse to high timing to low fuel pressure and high fuel pressure. It's just the nature of the beast I guess lol. But they sure do get down at full throttle! Like CaptPhil said mine is smokey as crap until about 15 psi of boost if over 1/4 throttle and embarrassing thing to pass someone, pull into traffic, or any little aggressive driving on the street. At night I've forgotten about it before passing someone and when I get around them I don't even see there headlights sometimes. Now I get a nice long running start so I can smoothly get into the throttle without excessive smoke. But setup does make a difference to. I have stock cam and stock heads with low compression. Winters I can't start the truck without plugging it in and I'm in Texas. Lol. Anything under 34* it won't start.

My 80s don't haze even when it's 30* put you need to tweak tuning more or you have a injector problem mine also starts without being plugged in at 19-38* it doesn't like it much but it does it.

Or its just your low compression being the problem
 

quinton

Active member
Nov 28, 2011
1,883
0
36
Granbury Tx.
My 80s don't haze even when it's 30* put you need to tweak tuning more or you have a injector problem mine also starts without being plugged in at 19-38* it doesn't like it much but it does it.

Or its just your low compression being the problem


More than likely it's my low compression. I have my rings filled pretty good also. In the colder weather it does run a lot cleaner of course but summer it's pretty bad. I bought these nozzles used with unknown miles from a sled pulling truck.
 

PACougar

Active member
Jun 27, 2012
2,105
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36
41
El Dorado Hills, Ca
My 80 over nozzles on stock body are are smokey as crap no matter what. I can drive it but no romping on it anything over 1/4 throttle. Even at idle it hazes black smoke. Ive tried everything in the tuning to low pulse to high timing to low fuel pressure and high fuel pressure. It's just the nature of the beast I guess lol. But they sure do get down at full throttle! Like CaptPhil said mine is smokey as crap until about 15 psi of boost if over 1/4 throttle and embarrassing thing to pass someone, pull into traffic, or any little aggressive driving on the street. At night I've forgotten about it before passing someone and when I get around them I don't even see there headlights sometimes. Now I get a nice long running start so I can smoothly get into the throttle without excessive smoke. But setup does make a difference to. I have stock cam and stock heads with low compression. Winters I can't start the truck without plugging it in and I'm in Texas. Lol. Anything under 34* it won't start.

You sir have a actual problem. My 100 overs paired with a Socal 9100 wasn't that bad.
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
Most likely you have one of two things going on. I would bet that the smoke can be cleaned up a bit in tuning. I say this because you more than likely are cutting pulse in the wrong places and it is compensating by pulling fuel at a higher mm3. If that is the case it will black smoke at idle. Check the idle mm3 first. Try to keep it close to 10mm. As you cut fuel in the low mm3 areas the truck will be much more smokey. We do not have full control over every aspect of the computers interpretation of data. If you would like to send me a log of your truck at unless hot, in gear, in drive, normal driving and wot driving and I will see if I have suggestions that will help you. That's just a offer that I'm throwing out for you.

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S Phinney

Active member
Aug 15, 2008
4,008
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28
Quncy, Fl
I heard somewhere that even if you swap 100% nozzles onto stock bodies, they are not true 100% injectors, and a modified injector with that same nozzle will flow more and be a true 100% injector, is that true?


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It is true that 100 over nozzle flow is not 100 over assembled injector flow. Flow increase as exponentially with pulse and pressure. For instance, a stock Lb7 nozzles flow is 1080 ml/min and it gets extruded to 100 percent over so it is 2160 ml/min. Now the stock assembled injector flow at 160 mpa and 1700 us is 123 mm3 and the 100 over flows 204 mm3 at the same pulse and pressure. You can see that it isn't 100 percent at that point. Now take the pressure to 180 mpa and 2800 us and the stock flow is 207 while the 100 over flow jumps to 360 mm3. You now have a 75 percent over flow in assembled form. There is a tremendous difference in smoke levels as size increase. Say going to 200 overs and the flow jumps to 520 mm3 at 180 mpa and 2800 us. It is a huge difference. You will feel it and see it more than you would like to in smoke levels. I actually have my 200 overs doing pretty good by most people's standard of smoke but I have many hours in tuning on it. My goal was to have it as good as the 100 overs but that isn't going to happen. I made some changes to some mechanical aspects if the engine thus time (camshaft) and I know I will see positive results but most likely won't be where I want it. Making power is really easy. Making power and having all aspects of the truck act tame with no ill side effects and still make that pure unadulterated power is a art.

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x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
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Lexington, Ky
I liked my 100s... you will have way more fuel on tap with 200s than your truck will ever need.

If you go 200s plan on putting a bar in your truck. If you don't want a. AR and make one pass wonders I'd go for 100s.

Yours was an lb7, he has an LBZ. Big difference. I would get the biggest set you can afford.
 

PACougar

Active member
Jun 27, 2012
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El Dorado Hills, Ca
Yours was an lb7, he has an LBZ. Big difference. I would get the biggest set you can afford.

I would size the injectors for the use. Competition only, then sure go wild. Otherwise I'd weigh the options carefully. Lately there's been this trend where everyone thinks they need massive injectors or they'll blow up their engine, pretty soon running a fractional pulse width will be the next big thing:roflmao:
 

x MadMAX DIESEL

<<<< No Horsepower
Dec 30, 2008
7,535
1
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34
Lexington, Ky
I would size the injectors for the use. Competition only, then sure go wild. Otherwise I'd weigh the options carefully. Lately there's been this trend where everyone thinks they need massive injectors or they'll blow up their engine, pretty soon running a fractional pulse width will be the next big thing:roflmao:

Nothing wrong with low 1000!
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,743
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Phoenix Az
I would size the injectors for the use. Competition only, then sure go wild. Otherwise I'd weigh the options carefully. Lately there's been this trend where everyone thinks they need massive injectors or they'll blow up their engine, pretty soon running a fractional pulse width will be the next big thing:roflmao:


Hey I run small pulse width all the time!.....





At idle lol
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
CR, Cam, Convertor, tunes, climate, turbo set up and who did the injectors all have a big part of smoke. Here's what people need to think abou . Do you ever plan on putting a cage in it? Lol
 

S Phinney

Active member
Aug 15, 2008
4,008
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28
Quncy, Fl
Do you or anyone have flow charts to compare? lbz flow about 88 percent of what a lb7 flows. 280mm3 at 180 on a 60 over lbz would be like 315 on a 60 over lb7. If anyone has a 60 over lb7 flow chart to check??
The lb7 60 overs will be right there at 300 mm3 at 2800 and 180. The newer body are more efficient with flow than the lb7. Their efficency helps overcome the nozzle flow difference. The nozzle flow numbers would be around 14 percent different but in assembled form there is only 7 percent difference.

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