Just curious what you guys are seeing as normal boost when towing at speed say around 65 to 70. I live in florida so I know my elevation my be different which can effect boost pressure. I was towing about 6500lbs yesterday mostly flat road but some very slight grades and my boost at 65 to 70 was between 12 when on a level grade and close to 18 and 20 sustained on a slight grade say 5%. I guess what I'm asking since I don't have a after market monitor yet that wil let me know my Egt Temps is say 20lbs of boost sustained for long distances ok? Normal? What would the max sustained boost be for long periods of time.

Also: I have 3:31 gears

Scott

 

I have an 08 dually.. most of the time on flat ground, boost is under half. and uphill its higher, sometimes max. I don't really pay any attention to it. I pull a 7000lb, flat front enclosed bumper pull car trailer. the road is what the road is. I don't race, I just drive.

IF you were doing 100% boost ALL the time, then there might be a problem, but I don't know how you would do this..

I just installed a tuner and am monitoring egts for the first time.
going down the road the number is like 600.. uphill climbs to 1000,1200, downhill like 400..

if I floor it and hold it there, I can get over 1500.. but I'm doing almost 80 by the time the temp gets there.. and that is with an additional 275 rear wheel horsepower and scary power acceleration!..

and I know to get the 'best' mileage, I should keep boost under 10, and rpm under 2000 and mph under 60.. yeh, I don't live that way. I don't race, and I don't baby my truck. They are made to do a job, day after day, and if they can't then I'll find another one that can.

Sam

 

Hi Scott,

I understand your concern, but you will not hurt this engine by towing. I'm not certain what Ford rates the max sustained boost at, but it is controlled and closely monitored by the computer. Your truck would de-fuel and lose some power to keep things safe long before you ever did any damage.

Remember that these are rated at a max of 33,000 lbs GCVWR. A high-profile trailer weighing that much would likely have the engine running 30+ PSI for hours on end while on the highway, and it wouldn't hurt anything.

I know it's not the same engine, but in THIS TEST the 2011 Super Duty was tested against a 2011 Silverado while hauling 19,000 lbs up the nastiest highway grade in the nation. Both trucks were climbing that hill at full boost and engine load. For 10 minutes straight with no breaks at high altitude. The 6.7L lost for reasons we won't get into here, but this illustrates the point that you will not hurt these things by towing!

 

I beleive that at 41 psi the pcm will hold it down. I have hit that a couple of times and you could hear it dump the excess boost.

The motor will hold more than that though.

I suspect your egt's to be somewhere around 600-800 based upon your discription.

 

Normal...... Up hill,Flat how much weight... We weigh @ 22,600 GCWR. Came up fancy gap this afternoon..speed 60mph, Trans temp 192...EGt 1295, Boost over 30.

Down the other side...boost zero, trans temp 151..egt @ 600... Normal ???????

 

Yeh, seems great!

Sam

 

I agree, those are great numbers.

I did sliding hill as my hardest last summer, Combined I think I was closer to 24K. Truck panted some, I had 230 eng temp 220F tranny (only at the very top) and egt's of about 1350 egt's. I could only muster 55 mph.

 

thanks guys all great responses. Its always good to here how other vehicles operate under different conditions.


Scott

 

My point is there isn't any normal. Depends on where you are and what you are doing.
My Lie O meter was reading 4.4 mpg going up the hill and 26 down the other side.
We did those hills going into gettysburg last summer and we thought the motor was going to come apart. Had to pull over at the top to let everything cool.

BTW...Did 1100 miles Florida to Northern Ohio..had one regen at about 600 miles.saw it on my gage as the EGt increased by @ 400 degrees.

 

in Florida too. Tow 15k fiver and boost is usually around 8 - 10 on flat and 20 + on hills in northern states. Never had probs. hope this helps