Towing temps boost pyrometer and gears

morgankshaw

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Hey guys. Trying to determine what to do to improve my towing. Here's the lowdown:

87 f350 with a 92 7.3 ats turbo zf5 trans 35/12.5/17 tires measure 33.5 with a tape and straight edge 4.10 gears 4x4.

The truck feels like it struggles towing my 5000lb toy hauler. In the hills it's horrible. But has improved some since I've turned up the fuel and had idiot help me adjust the timing. I also upgraded the exhaust to 4 inch and bought a boost guage and pyrometer.

Highest I've had the pyrometer go is about 1050 stomping 4th gear 9 lbs boost going about 55. 5th is almost useless hills or flats.

So here's my question. Upgrades to the motor or upgrade the gearing? I was considering moving up to 4.56 gears to help the old truck out. At least then I could get a little help on the hills. Anyone else have experience with gears?

Also what does your pyrometer read during towing? On small hills in 4th going 50-55 I'm probably 800. On the flats doing 55 in 4th 600. Can I continually run it at 1000?? Or is that bad news?

Thanks.




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Black dawg

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Been awhile since I had gauges in my truck, but I remember on flat ground at 18-20k gross, egt would be 900 with 5 psi or so. On a big hill, several miles of 6%, if I ran it wot It would make 1200 deg with 15psi+.

this is with a maxxed pump,088 turbo and 6.0 intercooler
 

morgankshaw

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Been awhile since I had gauges in my truck, but I remember on flat ground at 18-20k gross, egt would be 900 with 5 psi or so. On a big hill, several miles of 6%, if I ran it wot It would make 1200 deg with 15psi+.

this is with a maxxed pump,088 turbo and 6.0 intercooler

What gearing and tire size did you run?


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morgankshaw

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Ok. That's what the math tells me I'll be back to if I adjust the gearing. I'm thinking if I can't get the power i need 4.56 won't kill me if I upgrade to a cummins in the future especially if I go with even bigger tires.

But in the mean time i don't know why a 5k trailer is so much work. I bet with my current tires snd 4.10 my effective ratio is between 3.55 and 3.73 though. That can't help


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Clb

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I have that exact drivetrain..
Truck in my sig\pic
Brb
235\85\16 stock pizza cutters
My 5er is 5k dry
Stock pump,bb's max egt 1100 at 11psi pullin a good og hill, hwy 120 priest grade calif.going from merced to Yosemite
35-45 chasing traffic up the hill having to lift...
+1 on tire size....
 
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morgankshaw

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Is the Motor overall healthy? Tires do make a big difference.
Far as I can tell. I've been working on it since December. But there's no obvious signs of anything being wrong. Its a far cry from the brand new ram 2500 I had. Maybe I'm just super spoiled.


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snicklas

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Another thing to consider, what does the front of your trailer look like? Is it extremely tall and flat? When I towed my 21' travel trailer, the frontal area of the trailer was fairly small compared as to what was "shadowed" by the Excursion. My trailer was less that 11' tall, and 8' wide. The Excursion is almost 7' tall and is 6' wide. So imagine what the head-on view looked like.... you would see mostly truck and a little trailer around it. But if I had a trailer that was like Travis's old one, it was as tall as closer to 13 feet tall and was max width... 88 inches I think... plus, my TT sat fairly close to the ground, maybe 18-20 inches, but his was closet to 36 inches off the ground, so there was more air flowing under and catching the bottom. Part of your issue may be overcoming the air drag of a huge frontal area..... plus, with my Excursion, I don't have the air crashing over the cab into the bed and then into the front of the trailer, I have more of a slipstream between the two...... something to think about.... pushing air is a *****!!!!!

Think about some of the "super cars".... they can go 150 on less than 500hp, but to get that extra 50mph to hit 200, it takes at least a 1000hp.... all has to do with being able to break wind...........
 

morgankshaw

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Nothing ridiculous
But it's def going to need more go to get up a serious hill.
I'm seriously considering a cummins s swap but won't be able to afford that fir sometime. What kinda rpm and pyrometer temps are you guys running in the hills?

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CheckYourBuffer

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Nothing ridiculous
But it's def going to need more go to get up a serious hill.
I'm seriously considering a cummins s swap but won't be able to afford that fir sometime. What kinda rpm and pyrometer temps are you guys running in the hills?

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i love the truck hahaha
 

shawn deere

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What rpm does ur turbo build boost? Id look at that next. Maybe turbo mod from typ4 or WW2 compressor wheel. Also ur up pipes cant be leaking or itll be a dog
 

morgankshaw

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It's non Waste gate. It boosts through the scale but only gets up to 7-9 above 2500rpm


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rustygold

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Here's a handy chart. This is all on a 1 ti 1 you should be a 2 800 esh rpms for ideal pulling power in 1 to 1

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pelky350

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My 088 non gated in serious need of rebuild, leaking up-pipes turbo would get 9-11 psi unloaded. My ip was maxed out though. Check turbo system for leaks before the turbo this could be a factor here. Also with a 90cc pump and the turbo system sealed 100% pre turbo saw almost 20psi unloaded. Now I'm not sure how egts would be towing it's been a while since I've needed to tow anything and now I've upgraded my turbo system to a kind of factory style turbo which Made a bit of difference
 
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