How much Hp for sub 12 X's

[Burner]

How much HP do ya need for sub 12's on a CC 4x4 SB? I think the weight is 6,800+. What's the formula? I wonder what kind of times could be had by a 5,500 lb Duramax? :cool:


Burner-------> :D

[Burner]

Any gearheads........... :(

[Greg McCall]

HP required for quarter mile = (0.00426 x mph)to the 3rd power x weight

0.00426 x say 107 mph to the 3rd power = 0.0947066
x 6800 = 644 horsepower

[sdaver]

http://www.rpmoutlet.com/dyno.htm

[Michigana_Joe]

Is this really accurate for diesels? Since diesels generate such a high amount of torque at such low rpms the horsepower numbers *seem* to be overstated.

Seems like a calculation using the amount of area under the torque curve would be more accurate -- particularly for diesels.

Don't really know for sure, but I can't believe a 6800lb. Duramax with 489 RWHP would only run 14.00 in the quarter...

[dmaxalliTech]

I think Tomac should be in the 450ish range and I dont know if he dropped below the 13.0 range yet or not...

[sdaver]

I agree joe. I think torque is the wild card.

[afp]

Uh oh, here we go again. Torque is just applied force. You can get 300 ft lbs of torque with a big torque wrench at zero rpm. HP is the rate at which torque is applied. It takes power to rotate that 300 ft lb, and the faster you rotate it the more power it takes.

To generate 300 HP, you can do it with 300 ft lbs of torque at 5250 rpm, or you can get 300 HP with 600 ft lbs of torque at 2625 rpm. Reagrdles 300 HP is 300 HP--however you get it--and as such each engine (300 HP/300 ft lbs @ 5250 rpm or 300 HP/600 ft lbs @ 2625 rpm) is capble of the same amount of work.

Now, the 2625 rpm motor will likely last a lot longer at it's 300 HP................

Blaine

[Burner]

I had posed this question after reading about the “Sidewinder” Banks diesel.


On July 27, the Banks Sidewinder made its first drag racing appearance at Bandimere Raceway in Denver, Colorado. This was a major event sanctioned by the Diesel Hot Rod Association (DHRA).
So how did it run? The best run was 12.167 seconds at 115.10mph
The Sidewinder made its 12.16 pass with a single turbo and no nitrous oxide or propane injection – just straight #2 diesel fuel.


http://www.bankspower.com/sidewinder-dragrace.cfm


Michael Tomac had posted another Dodge running even faster, I think. I have not called the Huston dragway to confirm it but it looks “really” fast! :eek:
I would like to see Apples to Apples comparison (weight wise) between the Dodge, Ford and Duramax. Is there a 5,000lb Racing Duramax out there? Could it beat the Sidewinder?

Banks Sidewinder Diesel (http://www.bankspower.com/sidewinder-dragrace.cfm)


Burner-------> :D

[Michigana_Joe]

Here's an interesting read:

http://ubermensch.org/Cars/Technical/hp-tq

It would seem that horsepower is an accurate indicator of a vehicle's top speed, but a lousy one at predicting acceleration.

The sum total of areas under the torque for the specific RPM ranges utilized by each gear is a more accurate indicator. Unfortunately that's more difficult to compare and quite a mouthful compared to "500 horsepower"...

[CPMac632]

afp we are talking about tq at rpm which is a direct relation to hp. If the motor has a turbo diesel tq curve is it going to accelerate a certain mass the same as a gas tq curve with the same peak hp? Most of the hp or et calculators are set up for a certain type of curve and optimum setup. I don't think they are 100% accurate without being more detailed.

[sdaver]

click on the diesel trucks video

http://www.theclashofthetitans.com/vids/cat.asp?iCat=4

[sdaver]

some more of what you are talking about cpm
http://www.prestage.com/Car+Math/ET+and+Horsepower+Calculators/Calculate+ET+and+MPH+using+HP+and+Weight+/default.aspx

[afp]

I drag raced for about 8 years, and it was commonly accepted that HP determined peak MPH, but ET was a function of having the car set up right: suspension, gearing, convertor, carb size, etc.

My last car's engine was a 350 that developed 610 Hp at 7000 rpm on the dyno. However, best ETs required a 6400 rpm launch against the convertor and an 8000 rpm shift. It would usually hit the lights at 8500 rpm.

6400 rpm was above the torque peak, and 8000 rpm was well above the HP peak. However, as mentioned earlier, it took those parameters to so the engine spent as much time as possible under in the range where the engine accelerated it's hardest. Additionally, a propelry set up drag motor is "used up" at around 100-1200 feet down the track. If it's still pulling at the lights, then it needs more gear.

Apply that to a diesel truck simply means setting up the gear ratios so the engine spends as much time as possible--up to about 1200 feet--under the curve. A DMax may need to shift at 3000 rpm vs my car's 8000 for bet ETs. When all is said and done, it still comes down to the amount of HP getting to the track. The torque curve just determines gear, convertor, and shift points.

Blaine

[mtomac]

This weekend I ran an 8.22 and 8.29 in the 1/8 mile. Compared to my low 13 second 1/4 mile runs with 8.40-8.45 sec 1/8 mile times my truck should be in the high 12's now. The race weight of my truck is 6600#

[whatnot]

I would like to see Apples to Apples comparison (weight wise) between the Dodge, Ford and Duramax. Is there a 5,000lb Racing Duramax out there? Could it beat the Sidewinder?

Banks Sidewinder Diesel (http://www.bankspower.com/sidewinder-dragrace.cfm)


Burner-------> :D How fast do you think this will be?
http://www.thedieselpage.com/features/project2-4.htm