Fishin' for Input!
#46
My gauge set:
My plan:
My lisp just sent copious quantities of spray on my keyboard while proof-reading.
My plan:
- AE for reasons already stated.
- Muffler delete alone to compare data, performance, and sound.
- 4" as needed, with the configuration I decide, based on my experience with the stock pipe and muffler delete.
My lisp just sent copious quantities of spray on my keyboard while proof-reading.
#47
Oh, Rich.
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.
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.
Sometimes people ask if that drive wears me down. The drive is in the Columbia River gorge and it never gets old.
So... waddya think of my test track for diesel performance?
#48
Nevertheless, the reason I may come off as a "total tool" is because I have a real problem with misinformation. I know that you've seen it as well in your areas of expertise (whatever it is you do for a living and hopefully make good money at doing). I don't purposely go out searching for poor souls to make fun of or to try to insult. I go out with the intention of trying to explain exactly what's going on without beating around the bush or over-complicating things. I try really hard not to be derogatory or demeaning. I think that EVERYONE has the right to know exactly how something works without being belittled.
If you don't like the way I come across, that's too bad. I don't know you from Adam so it really doesn't bother me that much. I have never claimed to float on Bill's attitude. If you think that it hurts his company's sales, I'd beg to differ as I am never short on custom tuning work. I am who I am and I do what I do. I don't view it as a fault, just a personality trait.
Originally Posted by jkidd_39
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.
Last edited by cleatus12r; 02-26-2012 at 12:51 PM. Reason: Added some clarity to SOI calculations.
#49
As they say down under, "No worries, mate." I typically have 10-12 hours days... working 45 miles from home will do that.
Sometimes people ask if that drive wears me down. The drive is in the Columbia River gorge and it never gets old.
So... waddya think of my test track for diesel performance?
Sometimes people ask if that drive wears me down. The drive is in the Columbia River gorge and it never gets old.
So... waddya think of my test track for diesel performance?
Pretty. That makes a guy from my area pretty dang jealous.
I hear you on the driving part. I could do it for a living (as long as I'm not in a GM or Dodge seat because they're a little hard on the lower back).
Yep, you have stepper motor gauges as well.
As I said earlier, it's not really something that I would consider "good" for your turbo, but as long as you don't make a common practice out of it, you should be fine. A forum would be the place to hear about turbocharger failure (more specifically shafts that are snapping) if it were a huge issue.
#50
#51
Pay to play!
I must retort on one of my statements earlier:
After a little bit of searching through diagnostic information, it turns out that stock VE/P7100 mechanical Cummins engines' static timing can be set from the factory in the vicinity of 12 degrees + or - 2 (not 16-18 degrees as stated).
Adding even a few degrees of static injection advance WILL net some power/fuel economy increase in that case!
I went back a ways in this thread and came up with some more information that I didn't address initially.
jkidd_39 DID have a valid point about advancing SOI without increasing fuel to help with fuel economy/power, etc. Yes, it works with static timing as I finally got to explaining later but it's not really something that helps with the 7.3L for reasons below........
The technical reason for even dealing at all with when the fuel is injected is that in an ideal world, the peak combustion pressure will occur at 10-15 degrees after top dead center. This is what is accepted by many to be the ideal "time" for peak combustion to occur. With a static-timed engine (like the mechanical Cummins), the peak combustion "time" is going to occur later and later as the RPM increases. For all intents and purposes, let's assume that the flame speed is constant in a given scenario. 1200 RPM will be the engine speed with very little load (very little fuel being injected). 3700 PSI is the injection pressure of our injection pump (that's when the injectors "pop off"). Let the fuel be injected at 10 degrees BTDC. Once the fuel starts burning (delay), the peak cylinder pressure occurs at, say, 3 degrees ATDC. This is fine, the cylinder pressure is ok, there isn't any unburned fuel, etc. Now, we increase the engine RPM to 2200. The rate of fuel burn is exactly the same. However, since once the piston passes TDC, it is moving away from TDC faster than it was at 1200 RPM. Now the actual peak pressure is occurring with the crankshaft at a farther position. To put some actual values to it:
If the engine speed is 1200 RPM and the injection event lasts 1mS (one millisecond), the crankshaft has traveled 7.2 degrees. When the engine is turning at 2200 RPM, the crankshaft now travels 13.2 degrees in that same 1mS. By advancing the timing on one of these mechanical engines, the fuel spray is started earlier before TDC so that peak combustion pressure occurs earlier after TDC. Just a little information, you NEVER, EVER want peak cylinder pressure to occur near 0 degrees TDC or any time before TDC. That makes a big mess!!
The programming of the 7.3L already takes into account dynamic changes in when the fuel should be injected. Also, the injection pressure is constantly changing as well as the time that the injector is commanded to spray fuel. The SOI that is calculated is already more optimized to "hit" that combustion pressure sweet spot under all operating conditions.
That portion of my explanation revolves around instantaneous peak pressure with stock equipment. It doesn't take into account higher AVERAGE pressure (longer injection duration) or larger nozzle orifices (more fuel with time and pressure being equal).
Maybe that makes sense. There's an awful lot of stuff there.
I must retort on one of my statements earlier:
After a little bit of searching through diagnostic information, it turns out that stock VE/P7100 mechanical Cummins engines' static timing can be set from the factory in the vicinity of 12 degrees + or - 2 (not 16-18 degrees as stated).
Adding even a few degrees of static injection advance WILL net some power/fuel economy increase in that case!
I went back a ways in this thread and came up with some more information that I didn't address initially.
jkidd_39 DID have a valid point about advancing SOI without increasing fuel to help with fuel economy/power, etc. Yes, it works with static timing as I finally got to explaining later but it's not really something that helps with the 7.3L for reasons below........
The technical reason for even dealing at all with when the fuel is injected is that in an ideal world, the peak combustion pressure will occur at 10-15 degrees after top dead center. This is what is accepted by many to be the ideal "time" for peak combustion to occur. With a static-timed engine (like the mechanical Cummins), the peak combustion "time" is going to occur later and later as the RPM increases. For all intents and purposes, let's assume that the flame speed is constant in a given scenario. 1200 RPM will be the engine speed with very little load (very little fuel being injected). 3700 PSI is the injection pressure of our injection pump (that's when the injectors "pop off"). Let the fuel be injected at 10 degrees BTDC. Once the fuel starts burning (delay), the peak cylinder pressure occurs at, say, 3 degrees ATDC. This is fine, the cylinder pressure is ok, there isn't any unburned fuel, etc. Now, we increase the engine RPM to 2200. The rate of fuel burn is exactly the same. However, since once the piston passes TDC, it is moving away from TDC faster than it was at 1200 RPM. Now the actual peak pressure is occurring with the crankshaft at a farther position. To put some actual values to it:
If the engine speed is 1200 RPM and the injection event lasts 1mS (one millisecond), the crankshaft has traveled 7.2 degrees. When the engine is turning at 2200 RPM, the crankshaft now travels 13.2 degrees in that same 1mS. By advancing the timing on one of these mechanical engines, the fuel spray is started earlier before TDC so that peak combustion pressure occurs earlier after TDC. Just a little information, you NEVER, EVER want peak cylinder pressure to occur near 0 degrees TDC or any time before TDC. That makes a big mess!!
The programming of the 7.3L already takes into account dynamic changes in when the fuel should be injected. Also, the injection pressure is constantly changing as well as the time that the injector is commanded to spray fuel. The SOI that is calculated is already more optimized to "hit" that combustion pressure sweet spot under all operating conditions.
That portion of my explanation revolves around instantaneous peak pressure with stock equipment. It doesn't take into account higher AVERAGE pressure (longer injection duration) or larger nozzle orifices (more fuel with time and pressure being equal).
Maybe that makes sense. There's an awful lot of stuff there.
#52
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Tugly
1999 - 2003 7.3L Power Stroke Diesel
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10-24-2012 04:51 AM