http://www.vetteweb.com/tech/0407vet...l_information/

Guess so. They mentioned the test was on an Inerta dyno, which I'm not familiar with.

11 seconds to 145mph. I wish my car could go 145mph. ****.

I've heard the same thing about rims, "a pound on the rims is like 50 on the car".

Additionally:
http://www.se-r.net/engine/light_flywheels.html

 

Just to clarify. HP isnt a "fictional number." Its a measurement that is arrived at mathmatically. It measures work accomplished over time.

Torque is, IIRC, work done at the moment.


BC

 

For the purposes of automotive comparison, it's a relative measure. An approximation of what kind of performance you are going to get. It's something to brag about.

If I told you a vehicle had 100 hp, could you tell me how fast it could do a quarter mile? What if it was a 1.6 liter Civic, or a 650cc Sport Bike, or a turbine powered go-kart?

Now if we had the same car, with a 100 hp engine, and a 200 hp engine, we know the 200 hp engine would be faster, but still no exact time.

So back to the original point, horsepower is indeed a real number, it just doesn't mean much. Read any discussion about turbo sizes and there will be discussions about "usable power" versus "peak power". Terms like "properly sized turbo" and "dyno queen" come up frequently.

It's a number for the marketing guys to put on the brochure. Just like audio amplifiers that claim they're good for 1000000 watts. The real number to look for is RMS watts @ <= 1% THD.

If anyone was wondering, I was bored at work today.

 

perhaps he means brake rotors?

 

Brake rotors are cast iron, I don't know of any forged ones, but iron isn't usually (or ever) forged AFIK. There are steel rotors, but iron works better for most intents and purposes, because it's harder and resists abrasion better.

 

I had a lighten flywheel in my b16. I rev up very quickly, the car becomes very responsive, but on the same note, it revs down just as quickly too. My friends who are not used to driving it always stall the car and hate driving it.

It also makes engine braking almost non existent since there's alot less momentum. I can only imagine that it'll be the same with a rotary rotor; most likely more noticiable since its closer to the energy generating source.

 

Whatever the case, you're looking at a brand new design of the rotors.
Problem with forged components is that their heat expansion rates are different than cast items.
With the close tolerances of the rotor and rotor parts, I'd worry about tolerances.
All these forged piston owners bitch about "piston slap" until the engine warms up...


-Ted

 

This is funny ****. It reminds me of one of the first local 7 owners I met when I got into 7s myself back in 99. IT was this young dumbass redneck kid who thought his s4 NA base model was the fastest **** on wheels. He had dual 3" straightpipes, and painted it bathroom aqua green with no clearcoat, "RE" written on the fenders (he said it stood for rotary engine, my girlfriend at the time said it stood for retard), and little purple "rotors" stenciled on it in random places all over the car.

Anyway this dude swore his car had titanium rotors and that is why it was so fast. HE also claimed to have went 170mph on the interstate even though the speedo in his car stopped at 150 and he had tires 3 sizes too small for the car. I just kinda shrugged it off and went on with life, though I did make fun of him from time to time.

Sounds a little bit like what we are dealing with here.

 

Damn I'm learning chemisty and physics at the same time! haha! This is genius! haha! Who needs school! haha! j/p

I really didn't think that this would be such a hot topic! I was just wondering! haha!

Hasan

 

Horsepower is a very helpful number. Moreso, in fact, than torque, since cars have a transmission (which multiplies the torque). Horsepower is a good indication of how you can take advantage of your gearing to produce more torque at the wheels (actual torque at the wheels, not engine torque measured at the wheels). A dyno measures wheel torque and engine RPM. Then, it uses wheel RPM and engine RPM to establish the gearing and applies that ratio to the measured torque at the wheels, which is usually higher than the torque at the engine. If two cars make 200 ft*lbs of torque at two different RPM, the one with the torque at a higher RPM will accelerate faster because the car can be geared lower (increasing the torque to the wheels) for the same speed.


For the car to maintain the same speed in first and second gear, the engine would have to be at a lower RPM in second, right? For example, if 8000rpm in first gear is 40mph, and second gear gives you 40mph at 4000rpm, then it would take twice the engine torque to accelerate the car in second gear at the same rate. So, imagine you have an engine that makes 200ft*lbs at 4000rpm (152hp) and an engine that makes 200ft*lbs at 8000rpm (305hp). The first car has a drivetrain producing a 1:1 ratio between engine speed and wheel speed, while the second car is a 2:1 ratio. For both cars to maintain the same velocity, the engine speed of car 2 must be twice that of car 1. So, car1 is at 4000rpm making 200ft*lbs, and car2 is at 8000rpm making 200ft*lbs. They are going the same speed. If both punch the gas, car 2 will accelerate much faster, because it's 200ft*lbs at the engine is now 400ft*lbs at the wheels due to the gear ratio. Coincidentally, that car has twice the horsepower.

That's why horsepower is actually a better indication of a car's ability to accelerate than torque. In a car with only one gear, torque would be the deciding factor. Since automobile manufacturers have the ability to choose gears to suit a car's powerband, horsepower is the deciding factor as to a car's speed. It takes into account engine torque AND the torque-multiplying effect of a car's gearing.

 

titanium rotors....would be damn light!!
Is it possible?
Anyone tried?

 

Titanium rotors, even if possible, would be ungodly expensive. The only street car I've ever seen with titanium anything was one of Bob Norwood's Testarossas, and it had close to $150,000 put into the engine.