ForkHorn

Maybe someone can help me sort this out. Lets's say you have two identical trucks.

One making 330 ft lbs of torque with 4.11 gears for a torque multiplication of 1356.3. (330x4.11=1356.3)

Now the second truck also makes 1356.3 ft lbs through torque multiplication but does it with an engine making 396.7 ft lbs through 3.42 gears. (396.7x3.42=1356.3)

Which of the two trucks is faster? Does one have an advantage over the other?


I would prefer if the question was answered without using my truck as bias, but I have a 5.3/6l80 nnbs rcsb on 285/70/17's that I'm trying to decide if I should do gears, or save the roughly $1500 (it's a 4x4) for a 6.0.

Thanks guys

Edit: I should clarify that I mean acceleration. Top speed, and cruising speed are easy enough to figure out with a gearing calculator.

ForkHorn

I'll keep adding thoughts as I think of them... as far as the 1/4 mile is concerned, the 4.11s would put me crossing in 4th gear at a much better rpm I think.

I'm currently leaning towards the gears.. I may get them in and decide I don't need an engine swap. This truck is a daily driver that will probably rarely see the track which kind of contradicts the first thought in this post. But the truck probably needs gears engine swap or not

Gears will be tougher on my driveshaft and will spin it faster for the same speed

smokeshow

iTrader: (16)

If you assumed torque was a constant value...they would accelerate exactly the same. But in reality, whichever truck remains closest to peak torque on average would win in a race.

Atomic

iTrader: (42)

Yep, exactly...you need to look at the engine output over the RPM range through the gears, taking into account shift time and extension....as jake said, the car that spends the most of its time closests to peak power will win (assuming power is the same). Said another way, the car that puts out the highest average power over the race will win (assuming they are the same weight).

Clear as mud eh?

bstill

Hmm... My blazer has a torque multiplication of 7296. 400 X (4 X 4.56). I guess I did that right...

ForkHorn

Thanks guys. Good info. And yep bstill you did it right. I left out the tranny multiplication in my first post due to the two trucks in comparison having the same tranny. It's a variable that can be eliminated

bstill

I guess this is figured for 3rd gear (1:1). I was just throwing my transfer cases into the equation.