Highest Stock CP3 HP?

catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
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NE Oregon
My stock pump with 140k on it holds 24-25k on a 2300µs tune with 40% nozzles. HP calc has it between 685-703, depending on which one I use. I'm just wondering how far above 700 you could go using bigger nozzles. Or would it kind of even out after you go so big? ie, 100% sticks on my truck. Would I make more power, or would it not matter because FRP would still drop after a certain µs?

If you can hold 23-24 with 40% try bumping the pw in small increments and see if frp is holding. What is your tune commanding for frp? Is the actual meeting desired? l or is the desired at 26 and the actual not quite achieving desired frp? You can go with bigger ones and drop pw and make the same power. It takes X amount of fuel to make X amount of power with 100% s you will be able to get it in there faster. I would think woth 100% you would alsoneed to raise rail pressure at idle to keep from hazing.
 

Bonestock

Active member
Aug 9, 2010
1,358
1
38
Worland Wy
Not real sure on the Lb7/Lly pumps but on the Lbz/Lmm Kory has told me he continues to make horsepower with as much as 3500 drop in rail. My commanded is 25500 and actual is 23500 on 80 overs 2675 usec and it works real well!:thumb:
 

catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
0
36
NE Oregon
Not real sure on the Lb7/Lly pumps but on the Lbz/Lmm Kory has told me he continues to make horsepower with as much as 3500 drop in rail. My commanded is 25500 and actual is 23500 on 80 overs 2675 usec and it works real well!:thumb:


Sounds like a good combo. whose injectors?
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,198
362
83
At Da Beach
Yeah I can't really figure out why one would set it that high and limit the vanes that much. But I'd like to know the threory behind that.

On an LMM apparently if you drop the tables you will throw a p0299 under boost code. I just tried it and threw it 5 times just driving normal, plus it threw it again with the cruise set...:mad:

I will be guessings that's why they do it...
 

Harbin_22

Active member
Dec 4, 2010
3,858
7
38
Southern Indiana
On an LMM apparently if you drop the tables you will throw a p0299 under boost code. I just tried it and threw it 5 times just driving normal, plus it threw it again with the cruise set...:mad:

I will be guessings that's why they do it...

With my twins, the vanes are all the way open at WOT
 

catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
0
36
NE Oregon
On an LMM apparently if you drop the tables you will throw a p0299 under boost code. I just tried it and threw it 5 times just driving normal, plus it threw it again with the cruise set...:mad:

I will be guessings that's why they do it...

Thats why then. Quninton's is a LLY though. sounds like LMM's like to throw that UB code. so what happens is you open it up in the higher rpm like 2800 and up wonder if it would help egt's then? I got to plumb up my drive pressure gauge and see what things look like at different vane positions. also must be with a aftermarket turbo because I have 3 LMM's ive tune with stock turbos that are at 2.0% and no UB code ever.
 

Andrewslmm7

New member
Feb 27, 2013
63
0
0
Ct
i had alot of problems at partial throttle and highway lugging with the under boost code untill me and tony got two hours of driving together and while he was logging i drove the truck how i knew it would pop the code he worked some magic and i never saw it again to my understanding the computer only gives around 2psi in leeway up or down from desired... he changed some tables and never saw it again:D
 

DMAXchris

It’s only temporary!
Apr 28, 2009
2,273
2
38
44
Natrona Heights PA
If you can hold 23-24 with 40% try bumping the pw in small increments and see if frp is holding. What is your tune commanding for frp? Is the actual meeting desired? l or is the desired at 26 and the actual not quite achieving desired frp? You can go with bigger ones and drop pw and make the same power. It takes X amount of fuel to make X amount of power with 100% s you will be able to get it in there faster. I would think woth 100% you would alsoneed to raise rail pressure at idle to keep from hazing.

Thanks but I'm not looking for tuning advice. lol. :D:hug:
What I'm wondering is when do larger injectors become a moot point on a stock pump. For example; Would a truck with 100% injectors make more power at say 1700µs than a truck with 40% injectors at 2500µs considering they both held the same FRP? Or would the 40%s make more power due to the longer injection event? I know timing will play a huge role, but I'm just thinking hypothetically.
 

Mpsoldier

That just happened!
Mar 10, 2010
646
0
16
In my House
correct me if i am wrong but say a truck with 100 overs on 1700us to get the same power from 40 overs it would have to have a pulse-width of 3100us. 100 overs are injecting the same amount of fuel in a shorter time. Theres a point where the stock pump just wont be enough on 100 overs and 40 overs just depends on the tuning and supporting mods. hope this helps. :thumb:
 

Dirtymaxx03

Active member
Aug 4, 2009
3,109
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38
Thanks but I'm not looking for tuning advice. lol. :D:hug:
What I'm wondering is when do larger injectors become a moot point on a stock pump. For example; Would a truck with 100% injectors make more power at say 1700µs than a truck with 40% injectors at 2500µs considering they both held the same FRP? Or would the 40%s make more power due to the longer injection event? I know timing will play a huge role, but I'm just thinking hypothetically.

thats a good question. I think the timing difference between the two would be the biggest factor. The 100's, with a shorter injection event seems like they would make more power even tho they are injecting the same quantity of fuel as a 40 over.
 

catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
0
36
NE Oregon
Yeah certainly cannot run as much timing with the 100's because lets say with tuning PW we are injecting the same amount of fuel but because they have bigger holes more of it is going to get in before TDC. which is where bent rods come from. or atleast timing rattle.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,610
1,866
113
Mid Michigan
I have no idea what the heck half of you are talking about any more....


PWI on my computer
 

juddski88

Freedom Diesel
Jul 1, 2008
4,655
120
63
Chesterfield, Mass.
I don't tune my truck Tim. Not unless you count turning up the WOT pulse at the track, "tuning." :) I was just curious if there's a scenario were smaller nozzles could make more power on a stock pump.

See, that's a question that's not asking for tuning advice:D

And to answer it, yes there is- when the entire engine setup isnt optimized for the larger injectors. If you had stock motor A with 40% over injectors and dynoed 600hp with the airflow being the limiting factor; then you took stock motor B with 300% over injectors (given they were the same spray angle and hole count) you'd make more power with stock motor A. Why? Because overfueling causes lower cylinder temps and with that large of an injector youwwouldn't be able to pull pulse width enough and add enough pressure to compensate for the larger droplet size.