- Feb 18, 2004
- 84
- 0
- 0
just wondering if anyone runs w/ welds on a daily driver and how do u like it
Also what size do i need for my car????
thanks
Also what size do i need for my car????
thanks
I think that's a little out of proportion. Rolling Resistance is a linear function:LuvNLife said:Plus, the rolling resistance of the car goes WAY down.
propellerhead said:I kinda like the old school drag racer look with the 15s. It's so unrice. Plus, the light rims reduce unsprung weight and the tall sidewall will soften the ride.
Are they safe to use on a daily driver? Aren't they advertised as for track use only?
Thundermouse said:I think that's a little out of proportion. Rolling Resistance is a linear function:
weight * u = Resistance (in newtons)
where u is rolling resistance coefficient, which is the dynamic friction coefficient for the tire. The u for car tires on dry pavement is usually in the ballpark of .015 . Low-rolling resistance car tires on dry pavement can range from .01-.006.
Example 1 - normal tire:
Car is traveling at 70 mph (31.2928m/s) and we will use .015 for u.
1587.573295kg (3500 lbs) * .015 = 23.81359943 N of force resisting the roll of the car. To convert this force to a unit of power, multiply by the speed of the car and divide by 1000 to get KiloWatts:
31.2928m/s * 23.81359943 N / 1000 = 0.745194204 kW
and
0.745194204 kW * 1.34102208959503 = 0.999321889 Horsepower
Example 2 - Low Rolling resistance tire:
Car is traveling at 70 mph (31.2928m/s) and we will use .006 (the minimum) for u.
1587.573295kg * .006 = 9.52543977 N
31.2928m/s * 9.52543977 N / 1000 = 0.298077682 kW
and
0.298077682 kW * 1.34102208959503 = 0.399728755 Horsepower
Conclusion
With the use of the lower rolling resistance tire, the rolling resistance drops from 0.99 Horsepower to 0.39 Horsepower. That's a net gain of approximately 0.6 Horsepower. I think some ricers have picked up more hp on the dyno than that by adding cool neons and stickers.
That's absolutely correct! I was only addressing the issue of Rolling Resistance that was brought up earlier.Mustangl3 said:Isn't the point of using welds or any other drag wheel to reduce weight not friction? That would mean that you have to take into account the different weight of the vehicle in example 2. Plus rotational weight affects the vehicle more than dead weight sitting in the car. Drag lites weigh around 14 lbs each and stock bullet wheels weigh around 28 lbs each(if i remember from the weight reduction thread on modular depot), so you save around 56 lbs of rotational weight, which hardly affects friction at all, but will take less power to get moving and has a lot less inertia than the stock wheels. I've heard of people gaining a tenth in the 1/4 mile from adding draglites and skinnies up front, which would take more than .6 horsepower
meade01 said:With the weld wheels did you have to change the wheel studs and install spacers on the front and if so where did you get the parts, because I would like to install draglites on my 2003 GT. Thanks in advance.