Duramax Larger Injector Discussion
- Thread starter Blackbird1877
- Start date
Correct.
I think this information will be important or I wouldn't be dinking with it. But, I've learned never to make conclusions before seeing the data.
I think this information will be important or I wouldn't be dinking with it. But, I've learned never to make conclusions before seeing the data.
Ya, blah blah the theory. Gotta start somewhere. Gotta know the theory to start. Is it faster to cook one big chunk of meat or that one big chunk cut into smaller pieces?
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We're not talking about ground beef vs. pot roast though...
We're talking about a common rail diesel. Assume pressure is the same in both scenario's. Yes the smaller hole is going to atomize better that's a given. That nozzle can only deliver x amount of fuel per "on" time. So you open the nozzle longer. Say you look at cylinder pressure rise under boost yet you don't inject any fuel into the cylinder. Now on that graph suppose there is a point where cylinder pressure is highest, which means the most available oxygen in the smallest space, with the highest cylinder temp available. Isn't that where you would want to spray your fuel. (Assume that the stock nozzle is 100% atomization efficiency) Say my 45% larger nozzle is only 80% efficient by comparison.
The larger nozzle is going to have a much better chance getting "ALL" the fuel into the cylinder at peak cylinder pressure/temp than the stocker spraying before peak and after peak as the piston is traveling up (negative torque) and down the cylinder (expanding chamber volume).
Why did the LB7 have a larger nozzle? Better yet why did they downsize? I would guess emissions, not power.
Brayden
We're talking about a common rail diesel. Assume pressure is the same in both scenario's. Yes the smaller hole is going to atomize better that's a given. That nozzle can only deliver x amount of fuel per "on" time. So you open the nozzle longer. Say you look at cylinder pressure rise under boost yet you don't inject any fuel into the cylinder. Now on that graph suppose there is a point where cylinder pressure is highest, which means the most available oxygen in the smallest space, with the highest cylinder temp available. Isn't that where you would want to spray your fuel. (Assume that the stock nozzle is 100% atomization efficiency) Say my 45% larger nozzle is only 80% efficient by comparison.
The larger nozzle is going to have a much better chance getting "ALL" the fuel into the cylinder at peak cylinder pressure/temp than the stocker spraying before peak and after peak as the piston is traveling up (negative torque) and down the cylinder (expanding chamber volume).
Why did the LB7 have a larger nozzle? Better yet why did they downsize? I would guess emissions, not power.
Brayden
Hell I'm in Texas, most is about beef and everything has to be bigger. I've had these types of discussions and really don't care to have a " theory war ".
Oh ya, that marbled fat in that big steak is prime example of unburned fuel.
But, what do I know?
I like steak....
And, what good is all the extra fuel if the fuel will not burn to create btu for obvious reason?
And, looks as if atomization should be studied?
And, cylinder pressure? Why is higher better? Is the most for the longest time a consideration?
Should we still consider impinging? Is piston travel still relevant with time considerations?
Crank angle vs. piston travel, what do we know?
I'd rather talk about a steak
.
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Proud member of the Indiana Cattlemen's Association for a long time.. but this is the hardcore tech section so let's "trim the fat"
Brayden
Brayden
Mike was just giving details on how fuel was used for the short bus riders like myself
. Thank you mike for taking the time to post. :hug:
Uhh.. Yeah.. I have such a dish right here.. a steak that most people have failed to cook properly. Mine seems to be done just right.. Medium rare.. Not overdone.
http://www.youtube.com/watch?v=rNETZZuBjjM
Has anybody had an LBZ not crack pistons at this hp level?
http://www.fleeceperformance.com/Media/Jerrod_64mm_Cheetah_at_TS2.mpg
Same steak.. Well prepared.. Cooked at "HIGH HEAT" for a "SHORT DURATION" to sear in the juices and keep the good stuff where it's supposed to be Inside the bowl
Get it now?
Brayden
http://www.youtube.com/watch?v=rNETZZuBjjM
Has anybody had an LBZ not crack pistons at this hp level?
http://www.fleeceperformance.com/Media/Jerrod_64mm_Cheetah_at_TS2.mpg
Same steak.. Well prepared.. Cooked at "HIGH HEAT" for a "SHORT DURATION" to sear in the juices and keep the good stuff where it's supposed to be
Inside the bowl Get it now?
Brayden
As long as u can lick your fingers and your tounge beats your brains out you know u have cooked a perfect steak dinner.
Uhh.. Yeah.. I have such a dish right here.. a steak that most people have failed to cook properly. Mine seems to be done just right.. Medium rare.. Not overdone.
http://www.youtube.com/watch?v=rNETZZuBjjM
Has anybody had an LBZ not crack pistons at this hp level?
http://www.fleeceperformance.com/Media/Jerrod_64mm_Cheetah_at_TS2.mpg
Same steak.. Well prepared.. Cooked at "HIGH HEAT" for a "SHORT DURATION" to sear in the juices and keep the good stuff where it's supposed to be
Get it now?
Brayden
There is a certain tunner in this thread that has tuned a Stock lly motor to do 755rwhp with dyno sheats to prove it
. Im sure he knows a thing or two about the duramax motor. And about a steak also. just figure i would inform you.
Make sure you discuss tech in an adult, thoughtful fashion.
There will be no name calling here. It is not a substitute for testing.
There will be no name calling here. It is not a substitute for testing.
You wouldn't believe the temps if I told you. The smoke at the beginning is because the entire injector pulse width table isn't scaled for them.. just the WOT regions because I haven't had the time. If you look there is hardly any smoke near the end dragging 30,000lbs with a measly 2.5" turbocharger @ 38psi.
PS - Casper never cracked it's LBZ pistons. Nor has Wendy. Stock Sticks, lots of abuse. Finally melted all eight pistons in Casper, but no cracking.
I know McRat has made big power with stock sticks.. 3300us will make big power but it also makes very very big heat. The cure? Big air.. The downside to this is lag. And the fact that you are indeed spraying the crowns or running so much timing that you jeopardize hardparts.
I'm not calling anybody names here just trying to prove a point.. The thread is asking for the proof and I'm trying to provide. That truck never got above 1500 degrees that run. The other stock stick trucks that pulled that I have tuned will bury a 2000 degree pyro with 130hp less with similar airflow.
I'm not calling anybody names here just trying to prove a point.. The thread is asking for the proof and I'm trying to provide. That truck never got above 1500 degrees that run. The other stock stick trucks that pulled that I have tuned will bury a 2000 degree pyro with 130hp less with similar airflow.
And Pat has posted it.. melted 8 pistons.. too much heat. Also keep in mind that those #'s are with one single LBZ pump. If I could run 26000 psi and hold it I'm sure that it would be closer to 700hp with even better atomization and less smoke.
Pat weren't your pistons cut and delipped?
Pat weren't your pistons cut and delipped?
Wendy runs about 1500-1550 through the traps when running 12's.
That seems to be OK.
Casper really depends on how it's set up. At 797rwhp on the dyno, the highest EGT was 1600 during the pulls. But at the dragstrip it can go far higher in top gear.
That seems to be OK.
Casper really depends on how it's set up. At 797rwhp on the dyno, the highest EGT was 1600 during the pulls. But at the dragstrip it can go far higher in top gear.