INCREASED ROTATING MASS= DECREASE HP

wrong, increased rotating mass=decrease in acceleration, the dyno was not measuring acceleration.

Put 35 inch tires on the camaro and see what happens?

wrong again, we have 4.10:1 gears that make up for the size of the tires, the only way the tires are a deficit is if both vehicles have the same final gear ratio - the tires change the gear ratio reducing mechanical advantage, that's why our trucks come with lower diff gears, to remove the mechanical dis-advantage.

you guys are missing the bigger picture, the raptor was never meant to compete with what amounts to a muscle car. It DESTROYS the competition in the truck class, don't worry about what the effing Camaro's are doing.

 

War surfer, you mean to tell me that if i have 45 inch tires with 373 gears and you hav e 355 gears with 20 inch tires that the slightest increase in ratio would compensate. Your wrong. Think before you post. Camaro 342 ratio 26.5 inch tire vs raptor 35 inch tire 410?

 

War surfer, you mean to tell me that if i have 45 inch tires with 373 gears and you hav e 355 gears with 20 inch tires that the slightest increase in ratio would compensate. Your wrong. Think before you post. Camaro 342 ratio 26.5 inch tire vs raptor 35 inch tire 410?

There is a big difference between 3.42 and 4.10 and yes that is enough to make up for the larger tires. But I guess you know more about it than the Ford engineers. They clearly let the Raptors off the assembly line at a dis-advantage.

Don't take my word for it...

What's in a Ratio?

An automobile uses gear ratios in both the transmission and the drive axle to multiply power. The two ratios multiplied together equal the final drive ratio. Spend a few minutes in any bench-racing session and soon you'll hear rear axle gear ratios discussed. For many performance cars, 3.73s and 4.10s are common gear choices. The rearend gear ratio refers to the relationship between the ring gear and the pinion gear. By simply dividing the ring gear tooth count by the pinion gear tooth count, the ratio is determined. For example, if we divide a ring gear with 41 teeth by a pinion gear with 10 teeth we find that the gear ratio is 4.10:1 (41/10 = 4.10).

Tire diameter will also have an effect on a vehicle's final drive ratio. As tire diameter changes, so will engine rpm at a given speed. We can demonstrate this with the simplified formula: rpm = (mph x final gear ratio x 336*) / tire diameter (*see "Formulas for Success" sidebar). For example, given 65 mph, a tire diameter of 30 inches, and a final gear ratio of 4.10, the engine speed will be approximately 2,984 rpm--(65 mph x 4.10 final gear ratio x 336) / 30-inch diameter tire. If we reduce the tire diameter to 25 inches, the engine speed increases to 3,581 rpm. By installing shorter tires, the vehicle will accelerate as though it has a 4.73 (higher numerically) gear without the expense of gear swapping.

Because transmissions are comprised of several gear choices, the transmission allows the vehicle to accelerate quickly with lower gears and to maintain a cruising rpm using higher gears. In the '60s and '70s, most transmissions offered three or four gears with a 1:1 high gear. Using a TH400 as an example, First gear is 2.48:1, Second gear is 1.48:1, and Third gear is 1:1. Multiplying the 2.48 First gear by the 4.10 rear axle results in a final drive ratio of 10.16:1 (2.48 x 4.10 = 10.16). For most street performance applications, a 10:1 final First gear ratio is usually considered optimal. The disadvantage of operating a 4.10:1 axle ratio on the street with a 1:1 high gear is excessive freeway engine speed.

Fortunately, today's transmissions frequently utilize Overdrive high gears in the neighborhood of 0.70:1, which allow reduced engine speeds. Combine these overdrive transmissions with a 4.10 axle ratio and you have a fuel-friendly final drive ratio of 2.87:1 (4.10 x 0.70 = 2.87) in high gear. A TH200-4R overdrive automatic utilizes a First gear of 2.74, a Second of 1.57, a Third of 1.00, and a 0.67 Overdrive. With this transmission's First gear ratio of 2.74 combined with a 3.73 axle ratio, the final drive ratio >> yields a 10.22 (2.74 x 3.73 = 10.22). In overdrive, the final drive ratio equates to a Bonneville-ready 2.49:1.


The point is that the Raptor was designed to run with the 35's, thus they are not a dis-advantage - what I mean is, 326hp in the Raptor is 326 REAL rwhp, not some fake number that reflects the weakness of running larger tires.

 

I agree with thats what a raptor makes 326 rwhp. If this engine was put in a mustang it would make a lot more power and yes due to tire size. Inreased rotating mass= increase WEIGHT=DECREASED HP. Why do you think an aluminium driveshaft can increase hp on a dyno it is because of decreased rotating mass. Anybody in racing can verify this. The camaro really should not be compared to the raptor as the 6.2 in a chevy truck is detuned. I was just commenting on the camaro vs raptor 6.2. I would like to see a dyno graph of a chevy truck 6.2 vs raptor 6.2.

 

I would like to see a dyno graph of a chevy truck 6.2 vs raptor 6.2.

totally agree - but we both know the outcome already

 

Does anyone have any numbers from a Lariat,King Ranch,Platinum, Lariat Limited, H-D to compare to either an LTZ, SLT or Denali? Preference would be a Platinum with the 6.2 and SLT with the 6.2 and tow package...this would allow for a two speed transfer case and 3.73 gears...that would be a more apples to apples comparison

 

You are right. But the raptor 6.2 has 31 more hp than the limited at 380.