When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Not to fuel the fire, but 12V Cummins engines run fixed timing regardless of engine speed and load.
The computer programming that the 7.3L uses is fully dynamic depending on oil temperature, load, and RPM.
True. That is why I said that increasing timing makes a big difference. I may be comparing apples to oranges here but timing increases are the reason diesel engines can go out and gain 100hp with a chip.
Do you do your own tuning? I have never heard of having two identically fueled tunes w/ the only parameter changed is the timing
Good ol' Cody... always pourin' on the charm, that one.
Glad you could make it. I'm looking at air flow/boost dynamics and I have one question I haven't found an answer to: My boost "crashes" to 0 after stomping on it and letting off when passing a vehicle. A/Ox4 has a vid of his boost drop, but the situation I'm describing is far harsher than what I saw there. I mentally hear the needle bounce off the zero and I'm thinking I should back off the pedal a bit easier when passing. Am I correct in my concern, or am I just displaying my "anality"?
True. That is why I said that increasing timing makes a big difference. I may be comparing apples to oranges here but timing increases are the reason diesel engines can go out and gain 100hp with a chip.
Do you do your own tuning? I have never heard of having two identically fueled tunes w/ the only parameter changed is the timing
In case you didn't know who Cody is...quoted from the PHP About us website.
In April 2010, Cody, a Montana native, joined Bill and Corey. They were first introduced when he purchased their Minotaur Automotive Tuning Software in early 2009. A few months later (after reading many of his posts on various diesel forums), they asked him to become a moderator on the PHP Forum, and they've been great friends ever since! Cody is an ASE certified automobile technician with a decade of General Motors dealership experience under his belt, and he has been custom tuning 7.3L PSDs for several years. Cody has taken on many responsibilities related to the 7.3L PSD including answering e-mails, PMs, & phone calls, troubleshooting customer problems, and programming chips. In addition, with his extensive knowledge, Cody easily learned the ins and outs of gasoline tuning. He is an irreplaceable part of the PHP team.
I may be comparing apples to oranges here but timing increases are the reason diesel engines can go out and gain 100hp with a chip.
Negative, ghost rider.
FUEL is the main reason 7.3L engines go out and gain 100 HP. Since we're on it, the main reason I changed your "diesels" to "7.3L" is because the 7.3L is the ONLY diesel in light duty trucks that is capable of using a "chip".
Originally Posted by jkidd_39
Ase certified mech. Explains the lack of charm and know it all attitude.
I have NEVER, EVER used that certification to justify anything I've ever said to anyone in person or over the internet. In fact, that certification means very little to me as I know countless people who have for many years been able to pass those idiotic "multiple-guess-question" tests who I wouldn't trust to put air in my tires. I put ZERO faith in that testing method/system.
Oh, and thanks for the personal attack. Sorry that I don't sugar-coat much of what I say. I guess that's what we get in today's "everyone gets a trophy" society.
I have one question I haven't found an answer to: My boost "crashes" to 0 after stomping on it and letting off when passing a vehicle. A/Ox4 has a vid of his boost drop, but the situation I'm describing is far harsher than what I saw there. I mentally hear the needle bounce off the zero and I'm thinking I should back off the pedal a bit easier when passing. Am I correct in my concern, or am I just displaying my "anality"?
The boost gauge in the video is an Isspro EV2. Is that the same brand of gauge you're using? The only reason I ask is because that line of gauges uses a stepper motor for needle movement unlike most other gauges that use an actual air line and air core movement to make the needle move. The stepper motor ones, while there is nothing wrong with them, tend to move a little slower than others that use a spring to return the needle to "rest".
What's happening in your situation is once the fuel goes away, so does the boost (remember that discussion we had? ) because the drive pressure is suddenly gone (turbine side). It takes a lot of exhaust "power" to move air through the compressor. Even though the compressor isn't a positive-displacement pump, it still takes more power to spin the compressor faster at high boost levels. (I'm talking turbo shaft power created by the turbine.) The amount of power it takes will cause the shaft to instantly slow down to a speed where the drive and boost pressures are equal once fuel is cut off or flow is decreased suddenly (upshift, etc.) The noise heard during this time is air pressure being released back through the compressor housing. Like I said, the compressor is not a positive displacement pump so there is nothing "sealing" the air that has already been ingested through the compressor from going back to atmospheric pressure.
Is it bad? I suppose it can't be too good for stuff. Inertia is your friend most times, but when it comes to deceleration at a high rate, it can also be bad (think getting in a head-on collision with a non-crumple-zone car vs. one that collapses at a controlled rate). Although the outcome is never good, it's always better to decelerate "slower".
Also, I'm sorry that I haven't been around for the past week. I had to go to New Mexico to pick up my new work service truck.
Besides topping out at 60 MPH, the crappy roads through CO, and technically only being able to put in 10 hours a day (work stipulation, not mine), I got back on Friday. Yesterday (Saturday) I had fire class all day, and today is "get back to tuning because I have a weeks' worth of catch-up" day before full-time work starts again.
Negative, ghost rider.
FUEL is the main reason 7.3L engines go out and gain 100 HP. Since we're on it, the main reason I changed your "diesels" to "7.3L" is because the 7.3L is the ONLY diesel in light duty trucks that is capable of using a "chip".
I have NEVER, EVER used that certification to justify anything I've ever said to anyone in person or over the internet. In fact, that certification means very little to me as I know countless people who have for many years been able to pass those idiotic "multiple-guess-question" tests who I wouldn't trust to put air in my tires. I put ZERO faith in that testing method/system.
Oh, and thanks for the personal attack. Sorry that I don't sugar-coat much of what I say. I guess that's what we get in today's "everyone gets a trophy" society.
Perhaps we can still be friends since you have the sane views on the ase tards.
In regards to sugar-coating... It ain't coating. It's you defending the fact that you come off as a total tool. Give me info and prove me wrong with a polite tone I will be much nicer. Be a dbag and I can dispute everything.
I have learned you get much farther with a smile.. Seems like a typical tuner deal. Bill's attitude floats your company, while your main "competition's" I know everything views hurts more than help.
Perhaps we are looking at only one side of the tuning equation. It's a system so there are tons of parameters to change on these trucks. But to say tuning changes nothing seems strange to me.
Please feel free to get this back on track with dyno graphs or something concrete. Maybe even in a positive tone.
Is it bad? I suppose it can't be too good for stuff. Inertia is your friend most times, but when it comes to deceleration at a high rate, it can also be bad (think getting in a head-on collision with a non-crumple-zone car vs. one that collapses at a controlled rate). Although the outcome is never good, it's always better to decelerate "slower".
Or put another way in the words of an old saying, "It's not the fall that will kill you, it's the sudden stop." I would say that most moving objects suffer more damage due to rapid deceleration than that of overacceleration.