txballstryker

My truck is a 1996 4x4 3500 w/the nv4500 and 4.10 gears...I need to know how to calculate how much HP and Torque and how to get it to the ground...if a Ferrarri or a Corvette can smoke the rubber off AND run super high speeds, why can't I? Can you order any individual ratios in a gear set to help with this? Aerodynamic resistance is something I will have to overcome with pure power, but how much?

rootremblay

Money, Money and$$$$$$

txballstryker

The $$$$ goes without saying...I have already planned on 1500-2000 for the clutch, 800 for bigger sticks, 2-3k for a new twin setup, 1000 for head mods, 500 for all the p7100 work, etc,etc,etc... But I will be trying to push a 7200 lb brick through the air and because that for becomes progressively hard to overcome, I need some help with the real world numbers.

blackdiesel

hmm, do they make load range E tires that is rated for 150 mph? my dually at 135 started "floating" really bad. Not to smart takin a 4 ton truck that fast IMO

logskidder

150 mph in my old whooped Dodge...............it might take all 6 lanes of traffic to keep it under control....if you call it control

BCB

My 2500 was solid as a rock at 120

sixb

I would be curious to know if any of these 400, 500 or even 600 hp automatic trucks will do it without power braking! You can see what I have in my sig, and it's not even close to smoking tires. And I am way to chicken to go even a 100 mph. much less 150.

displacedtexan

You would prob need higher gears, and/or 5k RPM (and assocated work to turn over 4K)

I bet you could get some Toyo Proxies in some of the 20" sizes with a z rating.

J7 Diesel

rbrettctd has a first gen that will do it!! It was a auto non lockup with 3:07 gears or something crazy like that and now a five speed so theres some ideas!

David Alfonso

Diesel power mag. has a project truck they've been working on, but it's not a dually. It seems to be a street driven truck though and I thought I read that they did the standing mile @ 160 mph.

HOHN

Gee, I hate when I get called out like that

There are a bunch of reasons why a Ferrari or 'Vette can smoke the tires and run super high speeds, but you can't.

It's not just a function of gearing, and not just HP.

OK, I can feel a GEEKOUT coming on, so hopefully this won't get too bad..

Answering this question forces us to dig up the old theoretical discussions of what horsepower is, and what it means, and what does a dyno tell us and so on. I'll try not to get that far into it all...




There are two main reasons your truck won't do what a Corvette will do: Mass and RPM. If you think about it, the mass is the reason for the RPM difference, so it really just boils down to mass.


MASS. It's the single most relevant specification because it drives so many other things. How high can you rev something? How fast can I accelerate something? How much energy does (insert task here) take?

The answers to EVERY one of those questions involves MASS.

Now diesel engines also have RPM limits due to the slow combustion speed of diesel fuel, and you're not going to see 6000rpm diesels anytime really soon. The fuel burns too slowly to be able to transition from one piston stroke to another 200 times per second. (two stroke per rev, remember.) But perhaps a really oversquare diesel design might raise the rev limit over present limits.

Aside from the fuel combustion speed limitations, MASS is the main reason you won't get the 150mph speed limit and smoking all 6 very easily from a dually. POssible? Of course! Easy? Not a chance.

How much does a CTD engine weigh? I'm told about 900lb. Compare that to the 500lb of a typical cast iron small block V-8-- never mind the exotic aluminum engines in modern performance cars like a Z-06 'vette that are around 400#.

The block is very heavy. But that doesn't matter for engine RPM. Instead, it's the weight of that heavy crankshaft, those connecting rods, and the massive pistons. That heavy crank takes a lot of power to spin up quickly, and those massive piston/rod assemblies are designed for maximum durability, not fast revving. They are way too heavy for a serious accleration.

But, given enough combustion force, you CAN make those heavy parts accelerate quickly. It's sheer brute force.

The other thing we encounter is that "mass breeds mass." In other words, that heavy crank and heavy pistons and rods now need a beefier block and bearing to withstand the stress of the extra mass. We'll need q beefier transmission with bigger gears to handle the more severe engine harmonics and torsional vibrations in addition to the higher output. We'll need a stronger driveshaft and rear axle to deal with the violent application of torque when the clutch is released with a big trailer hitched up. We'll need heavier stronger wheels and heavier tires to handle the loads, too. So, like many things in life "stuff breeds stuff."

All this mass is the enemy of accleration, and with each layer of more mass breeding more mass, acceleration gets tougher to do, because F=MA tells us that it's going to take more and more force to accelerate an object as mass goes up.

**begin edit**
OK, part deaux.

Smoking 6 tires from a stop isn't that hard to do with a warmed up CTD. Running 150mph is possible too-- just tough. Doing BOTH, though-- that's going to be murder on your driveline, because you'll need tall gearing to hit the high speeds, and to light 'em up with the tall gears, you're dumping TONS of energy into your driveline all at once. This is a recipe for broken parts-- especially if you have sticky tires.

We'll start by figuring just how high an RPM we can make solid steam. Figure for a streetable 12V that 3700rpm is a good shutdown speed (though rumor has it that Banks ran their Sidewinder up to 4300 rpm in their top speed runs). Anyway, transmission is a variable, so we'll just assume you have an auto trans. Honestly, an auto trans is a much better fit for the goals of high top speed and hard launch. We'll assume 31" tires and calculate the axle ratio we need to hit 150mph at 3700 rpm.

3700 engine rpm becomes 5362rpm after the .69 OD ratio of the auto trans.
At 150mph, our axle is turning at an rpm we can calculate using revs/mile and speed. The 31" tires spin 655 times per mile, or 1637.5 revs/min at 150mph.

What gear ratio will take 5362 input RPM and convert it to 1637.5 output rpm? Simple divide and you get 3.275. The closest gear ratio usually offered near this is a 3.31 or 3.42.

To light up all 6 tires, you'd want a loose converter and simply rev up to make RPM with the pedal floored and drop shift from neutral to drive.

Then pickup all the parts off the driveway, rebuild your driveline and try again


Justin

Goalie990

i felt save at 145 in my truck!

Ph4tty

Well I drive a rwd dually and I can light up all four rears from a roll in 3rd or 4th gear with a 3.54 rear. And thats with less than 500 hp. If its raining and I'm on the interstate I can fishtail at will- basically just build boost and sideways I go

You're going to need taller wheels/tire, possibly a different rear, and some rpms to reach 150. Tires/ wheels would easier since the gears need to be changed in the front and back.

Our trucks are engineered to run stock power, thus when you double or triple that power weak points become apparent and need to be addressed. I'm trying adhere to the comprehensive bombing approach, even when that means that my hp per dollar spent is some kind of terrible =P

smokeyram

Just curious how you guys are getting so much top end. I have not done a gsk, or the free mod, so im sure theres alot of it there. Am I correct assuming that my govenor is whats holding me back? I have a straight shot commute, almost all highway, and im running 2200 rpms at about 85-90.
I need to get some of this delicious 100mph plus action.
I could shave 15 minutes off my commute with another 15 -20 mph.

displacedtexan

Yes, you need a GSK for the extra RPM. And I don't encourage it, I just suggest it