sneaky98gt
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RockstarMentality said:So what you're saying, its not that wider tires create more friction, its that the wider tire grips the road better in a sense of having more stuff to "grab ahold of and push on", for lack of a better term? The way I'm seeing this is that the rubber tires sink down into the crevices of the road, which i can see how that would increase traction.
However, I was always told that wider tires were "softer" and therefore had a higher (mu). If a person were to create a softer, skinnier tire it would have the exact same amount of traction as a wider one. I knew this was not the case, but I had no alternative solution or explanation.
No, the coefficient of friction is relatively identical for 2 different sized tires (assuming same brand, obviously). What is different is the normal force applied per unit area (i.e. pressure). In theory, if the tire and road were smooth surfaces, the size wouldn't matter because a smaller tire still has the same overall weight on it that the larger tire does; the smaller tire has less area on the road, BUT it has a larger amount of force per unit area than a larger tire, resulting in the same amount of traction.
BUT, because of the reason I explained earlier, that is not true. A wider tire will usually hook better than a narrower one.
97 king cobra said:The whole power/traction topic is really relative. Like I mentioned before, with my old setup I consistantly went low 1.4's and the car only made 380-390rwhp(depended on bottle psi). The car also ran 11.2-11.4 in the 1/4th. Most cars running that slow and making that little hp dont 60' that well. So saying hp directly relates to 60' or even the type/size of a tire is incorrect.
I think that your weight and steep rear gear ratio (IIRC) has a LOT to do with that. Throw 600-800 pounds of weight and some more typical 3.73 or 4.10 gears on your car, and you'd probably be 60'ing about what most "normal" street cars do (1.5-1.6). Also, your nitrous setup is making a lot more torque than lots of other setups.
I still maintain that if everything else is equal (weight, tire, suspension, gear, etc.), the 60' is directly related to the amount of torque you are putting on the wheels during that time.
While I was at work yesterday, I was actually thinking about this, and thought I'd do some quick torque multiplication calculations just to put what I'm saying in perspective. And to clarify, all I'm saying is that mostly stock automatic Mustangs don't require slicks and/or suspension to hook up at the track, and that there's nothing wrong with 2.0-2.1 60's from those types of cars.
So, car A. It's a 95 Mustang GT, 5-speed, COMPLETELY STOCK, other than 3.73 gears. I started out using a modded car, but even a stock 5 speed more than adequately illustrates my point. It launches at 5000 rpm, where it is making about 250 ft-lbs of torque. Now, let's do the math for the amount of torque it's making on the wheels (which is really what's important). 250 ft-lbs from the motor x 3.35 1st gear ratio in the transmission x 3.73 rear gear ratio. That equals a whopping 3,124 ft-lbs of torque on the wheels! That is very impressive, and certainly makes for some great 60's if you have the traction.
Now, let's move to car B. It's a 95 Mustang GT, AOD-E, a few simple mods like a CAI, underdrive pulleys, offroad H pipe, Flowmasters, and stock 3.08 rear gears. Because of the low stall speed on the stock converter, it can only leave at about 1500 rpm, where it is making 200 ft-lbs of torque (guesstimate). So, 200 ft-lbs from the motor x 2.40 1st gear ratio in the transmission x 3.08 rear gear ratio. That equals a dismal 1,478 ft-lbs of torque on the wheels, NOT EVEN HALF what the 5-speed makes. Does that put it in a little better perspective as to why the stock stalled/rear geared auto doesn't cut good 60' times?!?!? (not directing that at anyone in particular)
Hell, to even further prove my point, I'll use my OWN car (car C), with a positive displacement blower making a lot of torque even off idle, with a steeper 1st gear and rear gear ratio than the old AODs came with. With the stock converter, I've never been able to leave above about 1900 rpm. But for argument's sake, I'd generously guess that I'm making about 300 ft-lbs of torque at an arbitrary 2000 rpm. 300 ft-lbs of torque at the motor x 2.84 1st gear ratio x 3.27 rear gear ratio. That equals 2,786 ft-lbs of torque on the wheels. So in this case, even with the power odds completely stacked against car A, car C (which is a mid 12 second car) is STILL putting down LESS torque on the wheels at the starting line than car A (a mid-14 second car at best).
I hope (seriously) that some of you that don't agree with me now see where I'm coming from. I think a lot of people have been forgetting about the gear multiplication differences in an automatic and 5-speed car, as well has how limited a stock stalled automatic is in getting into it's powerband. So I hope that it is a little clearer why I say it is ridiculous for someone driving car A (or one with MORE power and MORE gear multiplication) to suggest that someone driving car B needs slicks/suspension because car B is half a second slower in the 60' than car A....
Rice_slayer said:@Sneaky, I legally drive my car to the track, who the hell in the right mind drives 2 hours on the highway on slicks?
Exactly my point....
I guess I should rephrase: "I like racing my STREET car in STREET trim..."