Towing with mods..Need advise

[Built240]

I have a 26hr trip tomorrow but dont have a EGT or trans temp gauge. I didnt think the truck would struggle the way it is and I dont want to damage anything. Input from people with similar mods and gauges would be great!

I have roughly 3k in the bed with a 5.5k trailer weight. Truck (I think 6500lbs) is a 03 f250 7.3l CC 4x4 with MBRP 4" turbo back, AFE intake, Max add on trans cooler and the older model edge evolution tuner. (Options: Stock-Tow L1- Race L2- Extreme L3 )

I have the programer set to Tow mode and trans seems to shift nicely but im worried about EGT's. Whats the best way to keep them in check?

On a 45min trip the truck seemed happy above 2k rpm running about 70+ mph but im scared to lay into the throttle on gradual hills etc in order to keep the speed. About how much can I lay into the throttle without downshifting or kicking it out of OD before EGT's start building?

On the flip side.. Anything below 70mph my rpm falls below 2k and engine drags in OD. Is 70+ ok or should I be keeping it out of OD and at 55mph and roughly 2.2k rpm the whole time?

Also, When I pop it out of overdrive for really long inclines or climbing mountains whats the right way to do this? Should I let off the throttle until it drops the gear or should I keep on throttle?

Thanks a ton to anyone who can advise!!

[OMCUSNR]

Originally Posted by Built240

I have a 26hr trip tomorrow but dont have a EGT or trans temp gauge. I didnt think the truck would struggle the way it is and I dont want to damage anything. Input from people with similar mods and gauges would be great!

I have roughly 3k in the bed with a 5.5k trailer weight. Truck (I think 6500lbs) is a 03 f250 7.3l CC 4x4 with MBRP 4" turbo back, AFE intake, Max add on trans cooler and the older model edge evolution tuner. (Options: Stock-Tow L1- Race L2- Extreme L3 )

I have the programer set to Tow mode and trans seems to shift nicely but im worried about EGT's. Whats the best way to keep them in check?

On a 45min trip the truck seemed happy above 2k rpm running about 70+ mph but im scared to lay into the throttle on gradual hills etc in order to keep the speed. About how much can I lay into the throttle without downshifting or kicking it out of OD before EGT's start building?

On the flip side.. Anything below 70mph my rpm falls below 2k and engine drags in OD. Is 70+ ok or should I be keeping it out of OD and at 55mph and roughly 2.2k rpm the whole time?

Also, When I pop it out of overdrive for really long inclines or climbing mountains whats the right way to do this? Should I let off the throttle until it drops the gear or should I keep on throttle?

Thanks a ton to anyone who can advise!!

If you tow, NEVER use speed, use rpms. Number one, its just plain not safe tow tow over 65 - you don't have enough reaction time if something goes bad (and it just plain wastes fuel - at 60 I can get 14, at 70 I get mid 11's). Next keep it above 1800 rpms all the time on the highway. If you cruise well at 1800 let it be there, at the first sign of a drop, pull it out of OD and keep it above 1800. If you hit a grade, try to keep it above 2k at all times and around 2.2 k for power. Its better to keep it in the power band at 40 m/h than lugging it at 60.

I have a 6.0 w/ manual trans - 2k rpms in 6th is 70 and 2k rpms in 5th is 56. Whenever I hit a grade 4+ I drop it to 5th and hold 2.5k rpms which is 60. I can hold that for hours w/out problems.

OMC

[Built240]

Ok, I wasnt sure if holding upwards of 2.2k for extended periods under load was ok with the mods I have. Being that I have an auto at what throttle point should I be pulling out of OD? At over 2k rpm can I give as much as 75% throttle to keep speed before dropping OD or should I drop out at less? say 50%?

Thanks again

[SmokeyWren]

Originally Posted by Built240

I have the programer set to Tow mode and trans seems to shift nicely but im worried about EGT's. Whats the best way to keep them in check?

Watch your pyrometer, and when it goes over 1,200º pre-turbo EGT, then back out of the go pedal a hair to keep it between 1,200º and 1,250º pre-turbo EGT until you get to the top of the grade.

But you can't do that, because you don't have a pyrometer.

So Rule 1 is to NEVER use a tune hotter than stock without a pyrometer. So set the Evo back to stock for towing. After you get a pre-turbo pyrometer installed, then you can use the hotter tunes and drive by the gauges.

About how much can I lay into the throttle without downshifting or kicking it out of OD before EGT's start building?

You won't have any EGT problem as long as the tranny is in OD. But as soon as it downshifts out of OD, EGT can climb up past the redline in a heartbeat.

On the flip side.. Anything below 70mph my rpm falls below 2k and engine drags in OD. Is 70+ ok or should I be keeping it out of OD and at 55mph and roughly 2.2k rpm the whole time?

Running the stock tune, it's going to downshift out of OD way before you hurt anything. So don't worry about it.

The only time you kill the OD is when comin' down the mountain with a trailer pushing on you. Or when climbing a steep grade that will cause the computer to downshift out of OD. If you can see the grade ahead that you know will cause a downshift, then manually downshift as described below before the computer does it for you. And after you downshift, then leave it in direct drive until you get to the top of the pass.

Also, When I pop it out of overdrive for really long inclines or climbing mountains whats the right way to do this? Should I let off the throttle until it drops the gear or should I keep on throttle?

With experience, you can judge whether the upcoming grade will cause a downshift out of OD. If it will probably cause a downshift, then I kill the cruise control, slow down to about 55 or 60 MPH, get off the go pedal, then kill the OD. Then reset the cruise at the speed I plan to take the grade. With gauges and my 60-tow tune and grossing 16k, I know mine will stay below 1,250º EGT at 55 MPH up interstate grades, and for some grades I can do 60 MPH without too-high EGT.

But if I didn't have a pyrometer, then I would run stock tune and not climb grades at more than 55 MPH in direct drive.

Ignore the stick shifter folks about "lugging". With an automagic tranny, your engine will never lug. Before the computer allows the engine to lug, it will downshift the tranny - whether you like it or not.

With my 60-tow tune, I can cruise at 1,750 to 1,800 RPM without the tranny automagically downshifting for every little bump in the road. But with a stock tune, I have to cruise at least 1,900 RPM because of the horsepower curve. There's simply not enough horses hooked up below 1,900 RPM with a stock tune when grossing 16k.

[Painted Horse]

When I think back to my 2000 7.3L ( which was a few years ago) I remember it would heat up when I lugged the engine. Or if I really romped on the engine. Well I never romped hard on it. So usually the only time I ever saw the EGT get hot was when I was pulling a long grade ( usually about 70 mph on interstate) and it tried to hold OD and lugged the engine.

When I noticed this I would force the downshift and the increased RPMs seemed to cool the EGT right down. I'm talking lugging along at 1800 rpm and downshifting to 2200 rpms. I could still go 70mph on the grade, I just couldn't do it in OD.

That truck had a bigger exhaust and a Superchip in tow mode.