[A Quiet Boom]

Originally posted by sithot
HP requirements for MPH

The formula:

HP = (MPH/234)3 x WEIGHT

The Math:

165 MPH / 234 =.7051

(.7051)3 is .7051x.7051x.7051 x 2200 (generously low weight for a Targa) = 543.78 hp

The BS:

No 2.4, 2.7, or 3.8 for that matter.

Any questions?

Tom

Sorry, wrong math! That is the formula to determine HP required to reach a given MPH from a standing start in the 1/4 mile, it's relatively accurate but doesn't take into account variances in aerodynamic drag, gearing, or shifting speed between different cars. According to Porsche's own website's specifications for the new 911 GT3 it has a top track speed of 193 (this implies it's the fastest they've taken it but whatever), a curb weight of 3075lbs not including driver and 415 HP.

Using your math it would take AT LEAST 1726HP for a GT3 to cross the finish line in a 1/4 drag race at 193 MPH. If I solve the equation for MPH based on the curb weight and stated HP I get right around 120 MPH for a trapspeed in the 1/4 mile which suggests it's a very solid 11 second car. that would be about right given the weight and HP based upon my own personal experience.

Anyone here know how much HP is required to move a 3000lb car of average aerodynamics down the interstate at 65mph? It's a LOT less than you think.

As for all us so called experts saying it isn't possible? Myself, cegerer, mr9146, and even TRE Cup have stated in this thread otherwise. TRE Cup is a respected car builder and he claims this Targa kept up with him when he pulled the redline of 7800 RPM in high gear in his 2.8L RSR.

I know of a frequently driven 302 ford V8 that turns low tens in the 1/4 mile "on the motor" in other words no power adders like NOS or forced induction, that car is shifted at or above 8000 RPM depending upon track conditions. I've stood right next to that car when it pulls a perfect launch and runs those numbers and I've seen the owner put the street tires back on and drive it home. If an American V8 can be built to survive 8000+ RPM on a regular basis and survive without frequent teardowns or limited driving what makes you think that an engine the started with a 7300 RPM redline and was built to cruise all day long at that redline can't be massaged up to 8500 RPM?

I think the sellers ad was stupid, but that doesn't mean I don't think the claims are possible. Guys 165 simply isn't all that fast in the grand scheme of things. How fast would an F1 car run the salt flats if the down force was set to a mimimum and the car was given a tall enough gear to reach max speed? Based on my short geared 911 box my car would hit 165 at just under 8000 RPM if I had the engine to do it. Besides I still think the factory redline is at least 500 RPM on the conservative side.