SHIFTING FROM A STOP WITH HEAVY LOAD

Cummins is not too bad... as in too baaaad. I tell you why. They gave me a Volvo with a N11 I think it was about 340 horse maybe 400 I don't know back in the 90's For steel coil hauling with a ravens covered wagon.

That was not a ... fast truck even though it was ungoverned at that time. But what it was a sort of a very... "Light footed" vehicle with which you can nurse a gigantic scary 52000 pound coil on your deck around a flyover just so with just enough of your engine and finesse in shifting just so to ease er through without spilling everything all over the place.

But if I did not do flatbedding with those little volvos the way I had to (Think coffee without lid on floor...) I would have hated the #### things. But they were wonderful. I ran 6 months on 10 between Houston and Jax until it finally accumulated about 56 seperate shop and DOT related breakages such as broken toggles, burnt gauges etc. Took about 3 days to restore it to 100% while I sat home for 6 weeks decompressing.

O the money I made down there. what with the rain and all Pipe east and chain west that winter. Shirt sleeve and jeans short weather the whole time too.

 

I drove '70's R models, ( with 5 and 6 speeds)and never ran them below 1200. On a downshift, at 1200, it would put it on the governor for the next gear, usually 2150 for the 300, a little more for the 237. The pyrometer ( do trucks still have those?) would climb to almost 1200 degrees, which I was told, was too hot for a Maxidyne.

 

I have driven A and B Cats, Cummins n14 and ISX, Volvo D12 and both 14 and 12.7 Detroit's, and unless your idea of heavy is much more than 80k, there is virtually no situation on flat ground that any engine needs to be wound to 1,800 in the low range. Mine is a 430 DDEC 2, and it won't even pull to 1,800.

 

I imagine trucks still have pyros. But new drivers are not taught anything like that so it's computerized into the ECM now. Particularly if you are trying to use lighter and less heat tolerant alloys these days compared to good steel that glowed near orange at 1450 degrees during a pull.

I also believe that some trucks are turned down so much that no one can ever damage a engine trying to do things a certain way. A form of control if you please.

Your post reminded me about certain macks and cleared some of the cobwebs of time. I don't have too much time with the macks compared to the bulk of miles run with other trucks. And obviously really BAD tractors I simply refused to get in em even if they fired me. (And did...) If you want some fun, try a suicide mack cabover. I drove one twice. Everything is there in your face against your knees and just below your shifter. And then there is the skull and spine slamming into that back wall and window glass right there.

You checked the cab hooks and springs bolts etc first before boarding those mack cab overs. Again I did not drive them long enough (Literally two trips about 400 miles total on beautiful blacktop 3 feet deep.. until the delaware anyhow...)

If the fleets are crying that drivers cannot be on time, by thunder, open the #### things up and let em run. All of this boo hoo about late will vanish and the true few who are REALLY lazy will reveal themselves soon enough.

 

True all. Normally when getting in a drive away truck we start out at an oil rig or fracking site with at least the power divider engaged and sometimes full lockers are required. The pad can be good rolled aggregate or mud up to your axles. Leaving the pad can involve steep hills, cattle guards, and switchbacks.

Often we are permitted up to 110,000 gross. Those are the pumps, mixers, and then the oversized sand chiefs (aka mountains).

I watched a tech at Swift dial down a lease operator's truck I recovered to get it ready for company driver use. As you described he put in max rpm at about 1600 for every gear and the special genius was allowing a maximum of 30 seconds at 1500 rpm's in second to highest gear, just so you can't climb a grade without dropping at least another gear.

I own an old Swift truck. The ECM is wide open. There's a safety issue involved in some of the slick and steep situations I get into. If I hit the governor at 1600 rpm's to start up a dirt hill that's north of 20%, that's a recipe for stalling or having to come to a complete stop and HOPE you have the ability to get underway in Lo...

...or start sliding backwards or having to back up in the dark.

No, I would far rather pick a gear, wind it up to 2000 or so to start that hill and hope to top out with a light foot on the throttle at around 800-1000 rpm's.

 

I've always felt that way. Give the driver the biggest darn motor, let them sort it out. Fuel mileage is not that much different, and sometimes, even better. Most of the ( cheapskate) companies I drove for had ridiculously low hp motors, in the name of fuel economy. In the late '70's and '80's, fuel tripled in price, so economy was the name of the game. Many times, I was questioned, "what took so long?" I said, well, if you'd give me more than half a truck that struggles at 35 mph on the hills with a load ( a certain 270 L-10 Cummins POS comes to mind) I'd be able to boogy down the road. It wasn't until I got my own trucks, that I finally drove a truck with 400 horse.

 

Sadly I was one of those with the unlimited truck one year. Stories of 130 plus all over my previous posts with that thing, full out 550 detriot and ungoverned to 2150 and fuel pump quits at 116 but momentum before you hit the upgrade say milesburg at 124ish but not one mile an hour more than that west on that curve, it will come right off and kill. You are still at 90 6 miles into the upgrade on that 80. Then the fuel pump kicks in and you crest near snowshoe at 60 or so 80K like a elevator. BEFORE you downshift.

Im glad I don't drive hellcats like that anymore. Ive always been a top end man. But... that one was hunts words... absolute crazy either way, good or bad.

And the worst of all that? I still got late a couple times. 130 aint make a dam difference when you sit on 70 at effinham waiting for the town to unclog gridlock so you can get to that fuel.. for about a hour. If you do some math you will find that 70 is averaging not much different in terms of time gained in short runs. There is no point.

However...

Texas says 85. Let em go 85. The tires in the big trucks are good for 85. Let's go Texas is dam big. Need like two days sometimes to get across at 55. Let's make some time. We can use it.

I remember the days fondly when 425 cats and other similar engines were the cat's meow and very well done for what they were. Fancy Gap was always showing off in the left lane loaded passing all us cummins peons.... (Fancy Gap I-77? VA to NC?) anyhow.. it is what it is.

Another area we used to get up and go well... it was 81 in va. When they first started governing trucks at 55 everyone moved left and stayed there to keep making time at 70 or better. Then MS Carriers I think were sometimes a problem at 68 when you had a 72 mph truck. The very early form of get out of the left lane parade float!!! "WHAT? Kick that back you *&% let's see who has a float around here with the hills of ironton coming up...."

Fun times.

Those days are over.

But.. considering People who are testing Hyperloop technology and other truly high speed stuff. Let's go, we are supposed to be professional. Open them up. But not too much. 85 is plenty. You will find most engines will develop good horse curve at 65 to 72ish in top gear and at 85 will have room to lug a little without holding up half of texas and pissing them off....

 

Ya know I always heard for a Texas Trooper to be able to exceed 110 MPH he had to have a bull wagon escort out front. Can't say I've ever had the pleasure myself

 

I know hills like that. You buzz it trying to grab the next gear, and it falls down so much you grab the next gear at 600 rpm!