How much is safe??

[OBSWIZ]

Running heavy up a grade in overdrive at 1500RPM is asking for problems with any inj-tune..this isn't a dodge a 7.3 needs RPM's..

 

[swamp_ratt]

Running heavy up a grade in overdrive at 1500RPM is asking for problems with any inj-tune..this isn't a dodge a 7.3 needs RPM's..

Pointed toward op?

 

[OBSWIZ]

At this statement..

But I still don't want enough power to damage anything by hooking up to the biggest trailer I can find and taking the biggest hill I can find in overdrive at 1500RPM all the way up. If the answer is that I need to stay stock then that's fine.

:badidea:

 

[swamp_ratt]

At this statement..

:badidea:

I never seen that one. DUH! Obviously not very smart

 

[Charles]

My 550 has 300cc hybrids in it and has no boost gauge, and only has a pyro from when I was tuning it. I could remove the pyro now with no issues as it's not possible to overheat it the way it's tuned.

I also have no chip switches or any of that.

One permanent program, ~300rwhp that will tow 30,000+ lbs gross all day long flat to the floor until you run out of fuel or melt the trans/axle down, whichever comes first.

A well tuned truck needs no switches, nor gauges.

 

[Pstroke96]

My 550 has 300cc hybrids in it and has no boost gauge, and only has a pyro from when I was tuning it. I could remove the pyro now with no issues as it's not possible to overheat it the way it's tuned.

I also have no chip switches or any of that.

One permanent program, ~300rwhp that will tow 30,000+ lbs gross all day long flat to the floor until you run out of fuel or melt the trans/axle down, whichever comes first.

A well tuned truck needs no switches, nor gauges.

true, but to get there, you need to tune it, also upgrade and untill you get everything to where it needs to be. you need gauges

 

[Estrogen Hostage]

At this statement..

:badidea:

I do realize that. I also understand what some of you are saying regarding the pyro on the stock motor, but folks tear the heck out of these trucks and I've not heard of a piston burned on a stock truck yet. I'm sure someone will come along and prove me wrong shortly, but I'll leave it at this:

A stock truck is so unlikely to burn a hole in a piston that it doesn't justify the cost of a pyro.

That's my opinion and I'm sticking to it. If I'm going to go ahead and get the pyro I'm thinking more seriously about getting a real tune to take advantage of those injectors.

 

[KPSquared]

My 550 has 300cc hybrids in it and has no boost gauge, and only has a pyro from when I was tuning it. I could remove the pyro now with no issues as it's not possible to overheat it the way it's tuned.

I also have no chip switches or any of that.

One permanent program, ~300rwhp that will tow 30,000+ lbs gross all day long flat to the floor until you run out of fuel or melt the trans/axle down, whichever comes first.

A well tuned truck needs no switches, nor gauges.

Who wrote this magic program? Sounds like a great thing for someone who just wants to make their truck work well.

What is in your truck Charles? I wasn't around PSN long enough before I came here to see anything but your amazing verbal ass-kickings handed out. You seem to be somewhat knowledgeable in this area.

Throw the OP (and me) a bone and maybe hand out that recipe instead of cryptic posts like

"Play your cards right and it will run cooler while making way, way more power than stock.

Think about that for a second..."

I'm really curious about your set up as I know a lot of guys in the OBS world that would be happy with just a few extra ponies and still feel safe driving without gauges.

A "well tuned truck" isn't all that easy to come by, considering all my local shop does is push Edge chips out the door all day long.

Any more info would be great. 300 HP and no worries of blowing the motor no matter what would make lots of people plenty happy.

 

[Charles]

Who wrote this magic program? Sounds like a great thing for someone who just wants to make their truck work well.

What is in your truck Charles? I wasn't around PSN long enough before I came here to see anything but your amazing verbal ass-kickings handed out. You seem to be somewhat knowledgeable in this area.

Throw the OP (and me) a bone and maybe hand out that recipe instead of cryptic posts like

"Play your cards right and it will run cooler while making way, way more power than stock.

Think about that for a second..."

I'm really curious about your set up as I know a lot of guys in the OBS world that would be happy with just a few extra ponies and still feel safe driving without gauges.

A "well tuned truck" isn't all that easy to come by, considering all my local shop does is push Edge chips out the door all day long.

Any more info would be great. 300 HP and no worries of blowing the motor no matter what would make lots of people plenty happy.

Alright...


Here's the exact recipe this truck got...



Hard parts installed on engine:

- Standard GTP38R with 1.15 housing and 4 " downpipe with straight exhaust.
- 300cc hybrids with 100% EDM nozzles
- Napa Open element paper filter


Tuning specifics:

-1.86ms of maximum pulsewidth at full MFD.
- ICP will ramp from ~500 at idle to 1100 - 1200 under light cruise to 2500 at full throttle, low rpm and work up to 3000 at full throttle and greater than ~2200rpm until redline at 3600rpm.
- Injector offset at 1ms across the board for the purposes of a static mechanical advance.
- Sea-Level and Altitude timing adder tables set to 6 degrees across the board. This provides ~21 degrees of timing at a towing friendly rpm of 2500. Conservative by all means, but sufficient for controlling cylinder temps with a rather narrow injection pulse. The timing maps could easily be pushed to 10 degrees across the board with substantial increases to power if a person had studs, although timing below ~1000rpm might need to be reduced for idle quality and cold-weather cranking reasons.


Nearly all additional adders and modifiers were nullified. The throttle application is perfectly linear, and the engine runs like a crisp mech pumped engine of similar power output and displacement.

 

[OBSWIZ]

So you can haul 15k+ up a 8% grade at 1500 rpm with your foot floored in your normal tow tune...I have to be there to see it..

 

[Charles]

So you can haul 15k+ up a 8% grade at 1500 rpm with your foot floored in your normal tow tune...I have to be there to see it..

I don't know if it makes enough power at 1500rpm to pull an 8% grade with a 15,000lb load, in OD but it would not run hot flat to the floor at that rpm. It simply might not maintain speed. And I'm not sure where 1500rpm came from anyway. I don't know too many people running light diesels at 1500rpm on an 8% grade with 15k behind them...

But.... in 4th or 3rd gear I'm sure it would trudge to the top flat-footed at 1500rpm with 15k behind it. Only problem might be keeping it at 1500rpm as it would probably start gaining rpm. An 8% grade is very tame for the hills around my house, and I routinely pull loads of 20,000lbs or more to and from my house, usually being equipment or hay. With the 1.15 on the 38R the engine generally pulls very hard down to ~1700 to 1800rpm before power starts to take a notable drop if I just had to wager a guess.

Flat-footed at 1500rpm I expect my EGT would stabilize at about 1250 on the nose if you stayed in it indefinitely.



When I hit the big hills on the north side of my house in the blueridge mountains, depending on load it will sometimes drag the engine down, and I'll have to downshift to maintain power. Sometimes from OD to 4th, then from 4th to 3rd at WOT in each gear on some of those grades. This is with a 300hp engine plugging along. Serious grades in other words. One particular stretch runs like this with a continuous uphill pull where I end up in 3rd gear most times, and this section lasts for 12 MILES...

At no time however will the engine EGT exceed 1250 with me flat to the floor with the engine getting drug down through OD after a few minutes, then all the way down through 4th after a few more minutes, then finally stabilizing in 3rd gear, flat footed.

The engine was tuned with the sole effort of extracting maximum horsepower while retaining a HARD EGT limit of 1250. So I'm a bit lost as to how you feel it some amazing happenstance that the truck can tow flat-footed up steep grades with a load behind it. Um.... that's precisely what it was tuned to do, while making the maximum amount of power possible without excessive amounts of injection timing for cooling.


Lastly, there's no "tow tune". The truck is simply tuned to pull. That is it's job. There's no program selection, you just crank it up and go. One, permanently loaded program on the PCM. It probably makes ~300rwhp and is actually pretty quick even being a full service bodied 550. The throttle response is crisp and clean like a mech engine of similar power.

 

[Charles]

Fwiw, I am changing out the rear diff lube today because it is destroyed. The fluid is scorched dark and smells like hell. This is in a Dana 135 with 4.88 gears.

The ZF6 pops out of 4th gear on a routine basis now as well.


Point being, with a well tuned 7.3L powerstroke exhaust gas temperature will be the least of your concerns, as a well tuned 7.3 will see the complete destruction of the drivetrain behind it when push comes to shove.

If you're engine is regularly exceeding 1250 degrees at WOT and you're not having any drivetrain problems due to severe loads being pulled, then the engine is simply not well tuned or it's ill-equipped for towing duty and you should reassess your turbocharger and nozzle selections.

 

[Jason]

I didn't read this whole thread, and that's probably obvious with my reply.

OP- I had Matt at Gearhead Automotive tune my truck, and not a single one of my tunes, from a dead stop to 100mph, will exceed 1300 degrees flat-footed. My tow tune, will drag a trailer uphill with the pedal to the floor and hover right at 1200, and then fall down to 1175, and that's where it stays. Tuners nowadays are alot better than they were several years ago. If the guy with 550hp is having problems towing, he needs to back his power down, there is no reason to tow with that much. My tow tune that makes probably 250rw, has no issues dragging whatever I put behind it at a respectable speed. I've grossed 33,000 lbs, and have held my own in traffic at 70, just fine. I've got 271k miles on this truck, over 120k miles of those have been running tunes, and it's just as stone cold reliable as it was the day it came off the dealers lot.

 

[Charles]

I didn't read this whole thread, and that's probably obvious with my reply.

OP- I had Matt at Gearhead Automotive tune my truck, and not a single one of my tunes, from a dead stop to 100mph, will exceed 1300 degrees flat-footed. My tow tune, will drag a trailer uphill with the pedal to the floor and hover right at 1200, and then fall down to 1175, and that's where it stays. Tuners nowadays are alot better than they were several years ago. If the guy with 550hp is having problems towing, he needs to back his power down, there is no reason to tow with that much. My tow tune that makes probably 250rw, has no issues dragging whatever I put behind it at a respectable speed. I've grossed 33,000 lbs, and have held my own in traffic at 70, just fine. I've got 271k miles on this truck, over 120k miles of those have been running tunes, and it's just as stone cold reliable as it was the day it came off the dealers lot.

Thank you.


And yes... that is how a program intended for towing should work.