Towing RPMs

[Goofyexponent]

I wouldnt be too worried about it, but it's not foolproof. A cold air intake or better yet, cowl induction would put most all worrying aside.

My truck was bone stock, but I turned the pump up a hair, I had no pryo, so I turned it back down.

 

[snicklas]

... Noob question - my 89 is bone stock; no turbo, no turned up pump, no power adders. Do I have to worry about EGTs at all?

I would say YES, definitely. Heath's crew cab was N/A before this rebuild, and it was at all stock setting, with a Pyro, and in 100% stock trim, empty, it would hit 1200 in a flash, without much effort, much less than a turbo'ed truck with a turned-up pump!!!! It has been said, all IDIs especially N/A IDIs should have come from the factory with a Pyro..... you can burn down a N/A just as quick, or if not more quickly than a Turboed one.......

 

[Goofyexponent]

Seriously? 1200? That's insane!!

That is a good bit of news to me!! Maybe I should get a pyro for my truck.

 

[Jake_IN]

This is a video from when i was towing the gooseneck to go rescue my friends jeep. Took these videos on two small hills to show what the EGT's do. Also get to here a chorus from the metallic brake symphony near the end.

http://youtu.be/7IypKYiftKA

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[chevytaHOE5674]

When my truck was N/A with the pump stock I could hit 1200 on the Pyro in a hurry if hot rodding it a little. Put a trailer of with any size to it behind the truck on a hill and I had to be careful.

Actually with the turbo and the pump turned up it is a little easier to drive in respect to the EGT's. Not so much skinny pedal is needed to move the load so I can keep the EGT's lower easier.

 

[Agnem]

A pyro is ALWAYS recommended. What with the weird fuels they are feeding us these days, the fuel your pump was calibrated for, technically no longer exists.

 

[hesutton]

A pyro is ALWAYS recommended. What with the weird fuels they are feeding us these days, the fuel your pump was calibrated for, technically no longer exists.

X 3! Pyrometer is a good friend to have in the cab with you. Lets you know when your poor IDI is getting hurt. Especially when they are N/A. My experience with turboing these IDI's is a huge improvement in EGT's when they are worked. Can't wait to see what the addition of an intercooler will do for the EGT's on the crew cab.

Heath

 

[pennsylvaniabo]

Here in PA i tend to run 4th gear 2500-2800 doing 50-55mph in the mountains. Flatland Ill run 70+mph at 2200-2500 rpms. This is on a 4.10 truck with 265/75/16 tires. I know my biggest issue with trying hills in 5th is tha it looses speed and egts climb, which causes truck to heat up a lot. Downshift to 4th, max the boost and egts hold steady and engine temp climbs, but a lot less.

 

[PwrSmoke]

I've been driving all kinda of trucks for almost 10 years. Yes, I tow with my ZF in 5th gear, but that also depends on teh load, speed and road conditions. If I have a car on the back, and I am on a flat highway, overdrive it is.

If I got a dump trailer with 10 000 pounds in it, 4th gear and never over 55MPH. You don't want to get too hyper with any type of load that is heavier than the towing vehicle...your truck.

Now. As far as lugging an engine. You can, but I DO NOT reccomend it with an IDI. I lug the BIG engines at work, because they are DESIGNED to do that...they have a torque rise that is phenomenal. In an ISX for example, as you are running up the highway at 1700 RPM, and you climb a hill...your torque will become greater as the RPM decreases...horsepower don't move the truck up the hill....torque does at this point.

These IDI engines need to spin fast to work efficiently. Run her off teh govenor all day should you wish, it won't harm it. But it won't do anything for mileage. If I am climbing a hill with my truck...no less than 1600 or so, but even at 1600 I am not full throttle...I don't like beating and pounding on stuff even though these engines can take that kind of beating all day long.

Very well said! It's almost exactly how I drove my '86 at 18,500 GCVW (C6, so no OD). I was never afraid to rev it and get the water pump spun up to cool it and get those EGTs down by getting cooling air thru it. A good general rpm tpo shoot for is the place on a power and torgue graph where HP and TORQUE cross. That's about 2600 rpm but at 2000-2200, the NA graph shows the engine just at the end of it's max torque and coming up fast on horsepower (about 125 hp & 330 torque) @ 2000. The Banks graph for my era kit shows 200 (flywheel) hp @ 2000 & 520 torque.

 

[robmoore11]

Oh jeeZ. My truck has Never had a pyro and has had many of heavy trailers behind it 5-10k (not me)

 

[RLDSL]

Yes, lugging is too high a gear. If you're giving it more than 3/4 throttle, and it simply isn't accelerating, or it is slowing down. The engine is "lugging," and you need to downshift to give it more mechanical advantage.

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Extremely close. Back when these things were new, the factory rep came by to the fleet I was working at and gave it to us as if you can't accelerate at 2/3 throttle you were lugging it. Now, it's OK to give it more than 2/3 throttle on a hill, just so long as it does not *require* full throttle just to hold ground, there are plenty of times when you are *gaining* rpms at full throttle climbing a steep hill coming up on grabbing another gear, then it's fine, if you think you are going to be able to pull the next gear without falling on your face, but in the long run you engine is much happpier if you never let the thing lug and make sure to drop gears when needed. These things pull strong between 1800-2000 ( and having an auxiliary trans to split the gears makes it real handy for keeping the rpms right in the sweet spot

 

[hesutton]

Oh jeeZ. My truck has Never had a pyro and has had many of heavy trailers behind it 5-10k (not me)

Most of the pistons in that 6.9 had burnt crowns with missing aluminum. Several also had skirt damage. EGT's are the enemy.

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Heath

 

[robmoore11]

Most of the pistons in that 6.9 had burnt crowns with missing aluminum. Several also had skirt damage. EGT's are the enemy.

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Heath

That only scares me a little. Maybe I should get one. What do you fellows think about glowshift?

 

[TWeatherford]

That only scares me a little. Maybe I should get one. What do you fellows think about glowshift?

Let me recommend this

http://www.auberins.com/index.php?main_page=product_info&cPath=5_26&products_id=230

I was leary of it because its so cheap, but it has lots of features and information that other gauges don't give you. They say its accurate to 0.2% I believe. It can be programmed (very easily) to light up a warning light or buzzer when a set temperature is reached, which is nice to keep from always starting at the gauge.

 

[89greendiesel]

1989 ZF-5. 2k-2300 on the flats in 5th with about 4-6k in trailer behind me. Truck weighs in at 6k full of fuel. i will have to go to 4th with much of a hill. Anymore weight than that and i would need more power to tow in 5th. Might be time to turn up the fuel pump and get a pyro....should probably have a pyro anyhow, eh?


that pyro link posted above looks my style.