I'm hoping this question belongs in this forum.................
I've read somewhere on this forum about downshifting at the top of a long hill and also about not letting your engine cool off too much while going down hill. I will be pulling a 30 foot fifth wheel through the mountains sometimes and would like to know just how to drive this "beast" so as to extend the life of all its essential parts. Could someone please attempt to expain to this amateur just how to drive my 6 speed manual, turbocharged, HO, and the purpose for doing each maneuver? In the next few weeks I'll have new gauges (boost, pyro, FP) installed on the pillar.
Thanks,
Monte

 

I wouldn't downshift until you need to.Just because you are pulling a hill doesn't mean you need to go to 5th.Only if it is lugging the motor.I prefer to keep it reved up a little more than some guys do.I think that is actually easier on the tranny and clutch.As for extending the life of the ''essential parts'' some guys like to double clutch all the shifts.I personally don't do this very often.I just wait long enough for the synchros to slow down a bit,and then put it in gear easy.As for not letting the engine cool of going down a hill,I have heard that too,but I wouldn't worry about that,your sig says you have no fuel mods so it's not going to run that hot anyway.Just watch the thermostat.And always cool it down after a good pull.Good luck

 

Just drive and don't worry about it. There is very little that you need to do differently than any other vehicle. Don't shut it off right away after a hard pull, let it idle for 5 minutes or so first. Keep the RPM over 1800 or so pulling big hills, don't let it lug to hard and you will be fine.

 

Watch your gauges. The pyro will tell you a lot. If it gets too hot, drop a gear.

Don't carry too much speed down hill. Slow and safe is much better than getting there first.

If you do not have rear disks, I would seriously do the rear cylinder upgrade. It is very cheap as far as mods go and helps out a ton on the braking.

I cannot tell you how much of a difference an exhaust brake makes on hills. I love mine. If you do not have the cash for it now, try to budget it in when you go with a bigger exhaust, assuming you are planning on a four inch exhaust.

 

I agree. I think higher RPM are easier on this engine than possible lugging.

Don't worry about excessive cooling. Just descend hills slowly. If you have to hit the brakes to scrub off 10mph, you're gong too fast. Just crawl down them and ride the brakes-- it will be fine. Slow sustained heat is easier on the brakes than superheating followed by cooling. This is why you have to go slow. TO fast, and the brakes overheat.

jlh

 

Or add an exhaust brake and don't worry about overheating the brakes. Then it will be even better!!

Rusty

 

The riding the brakes comment makes me nervous, ride the brakes- the brakes get hot = brake fade.
Class 8 experience tells me this is a bad idea.

Use a lower gear to slow your rig if you have a long, steep descent.

Exahaust brakes are awesome.

Buta gain, none of this is as complicated as it sounds.

How much does your trailer weigh?

 

Tool,
The trailer weights in at about 9000 and loaded about 11,000#
Monte

 

If you go slow enough, riding the brakes is, in fact, the best way to go.

What determines how hot the brakes get? Braking HP!!

Yes, your brakes have HP. Basically, how fast can they slow down a given weight.

But what brakes really do is convert mechanical energy to heat. The kinetic energy of you vehicle is given by 0.5(Mass)*(velocity SQUARED)

Notice that velocity is squared. This means is has a LOT more impact on the amount of energy to be converted than mass does.

So the brakes have to convert energy to heat. Since they themselves are cooling and losing heat as they do, then you have to ask: how hot will the brakes get?

This is a function not only of how much energy the brakes have to convert, but HOW FAST. Yes,the RATE of energy conversion is paramount.

If you slam on the brakes, they get a LOT hotter than they would with steady pressure.

So if you do the common practice of coasting then pumping your brakes, you have allowed the vehicle to pickup speed, and you are forcing the brakes to do MORE work!

It's much better to go slowly and ride the brakes, allowing them to dissipate a reduced or constant energy level. The trick is drawing this out for a long time so the brakes can dissipate the heat. TIME is your friend in this case.

Pumping the brakes is bad because it heat the brakes hotter and faster, which increases the likelihood of rotor warpage and brake failure.

So the next time youhave to go down a big hill with a heavy load (and don't have an E brake), just crest the hill slowly and crawl your way down at 10mph or so, riding the brakes the whole way. It's much safer and the brakes have a lot less strain put upon them.

JLH

 

#1 truck drivers rule , if you have to ride your brakes your are going to fast ,

just do the speed that is comfortable and you dont have to ride your brakes.

 

Get an exhaust brake, best money you will ever spend, you can go down almost any hill without having to step on the brakes, I tow about the same weight as you do, and have yet to have to step on them. And going 10MPH downhill is fine, as long as somebody doesn't run over you. Keep RPM's 1800-2200 while climbing, any less lugs it, any more flogs it!!!

Tom

2001.5 2500 4X4 5-Spd LB QC Black. Catcher ECM, DD Stage-1's, AFE, Bully Dog 4" pipe, ATS Exhaust Manifold, Silencer Ring MIA, JAKE Brake w/shifter switch, Geno's Banjo's, 3 Autometer's on the A-Pillar, Gear Vendor's O/D, Firestone Air Bags, Redline Oil throughout.
Soon-to-have 14cm Turbo Housing and RASP Pump (Thanks Olee!!)

 

Exhaust Brakes and a straight pipe are mean sounding down long grades... It will save you brakes. I'm still one the orginal shoes and got over 70% of the shoes left @ 58K on the clock!

I can haul a full box of firewood plus a 8x8x2 Trailer down out of the mountains and never touch the service brakes the whole 15 miles down a 7+% grade with twisting corners!

 

Thanks to everyone who replied to this thread. I guess I was reading too much into everything .
Monte

 

Dead on, stay off the brakes as much as possible, let engine backpressure/ braking do as much worka s possible. General rule is descend a hill at the speed that you can climb it, however, the horsepower and engine capabilities far exceeds the braking system on 6these things (as well as many modern OTR trucks) so I'd say go a little slower downhill. No need to be doing 10 MPH down a hill, that can cause a hazard in itself!!! When gungho' trucker crests hill at a much greater rate of speed and there you are doing 10 mph in his lane! Just be reasonable, drive within the parameters of your skills, experience and equipment and you will be fine.

Good luck.

 

Something that will make it easier on the engine when pulling a big hill and getting all heated up is as you crest the hill, just back off the throttle a little to let things cool down before getting into coasting down the hill. Makes the shock of getting cold fast a little easier.

You said you have class 8 experience, use it and drive the same as you would a big truck, there is really no difference, just lighter weight with smaller engine and brakes. I don't ever ride the brakes, sorry guys, a little light pressure to knock off 5 mph is not hard on the brakes nor does it heat things up. I keep the jordan set up so that I can drag the trailer brakes for minor slow downs withough hitting the truck brakes which will be cool if needed in a hurry. My light stopping is done with the trailer brakes. Works real good for me.

After a couple of bad hills with overspeed in an 18 wheeler you catch on real fast how to get it back under control again. You hit them hard, down gear, hit them hard, down gear, and keep doing that to get the speed dowh to where you can handle it. Try and ride them down and you just fade and get way too hot. First rule of life on a steep hill, you have to slow it down or die. This paragraph is ONLY for the do or die situation where you have screwed up and are running away. If you have been riding the brakes and get in this situation you are too hot to jamb them down one gear.

Another thing to remember when using the engine for a brake, you can let it climb up to the 3300 rpm figure all day long. The faster it is turning the more braking power it has. Cummins says it will not hurt it.