lonj

I thought some of you might be interested in the following link:
www.stealth316.com/2-calc-hp-et-mph.htm

You can pick any of the performance data that's been published for 1/4 mile speed, Et, Weight, Hp and play around with the formulas and see what you end up with for rear wheel HP.

I have seen weights ranging from 3135 to 3153. You would need to add in the weight of driver and a minimum of gas.
I have seen 1/4 mile speeds in the 125/126 range, and ETs in the 11.2s.

There are a lot variables that come into play in an actual car test. Most of these are small as compared to weight and HP. They will produces variances from the prediction however.

Nonetheless these mathematical models of performance suggest we may have significantly more HP than 475.
Remember, This is just for fun.

aamersa

Porsche and AP at launch did elude to the fact that hp is actually closer to 500.

918man

I think its 500 plus. This is purely opinion on driving the car.

Mike in CA

Fun to play with those. Thanks for posting. FWIW, the car that Car&Driver tested had a curb weight of 3197 lbs which included a full tank of fuel; figure adding at least 150-175 lbs for the driver. It ran 0-60 in 3 seconds and the 1/4 in 11.2@126mph. The 475 HP rating does seem conservative.

Macca

Ive estimated total weight of Sabines car with half tank of gas using specific gravity cals and an estimate of her weight clothed at 3351 lb assuming the car is stock with buckets and no cage.

The only solid facts we have from Sabine video are the 0-400 time of 11.2s. 1/4 mile is 402m

As we can fairly accurately calculate the weight of the vehicle (1520kg) with an assumption on Sabines weight clothed =68kg the Hales calculation is the most conservative at 471 BHP and plating with the others we see anything from 510 bhp upwards (using 122 mph as trap speed).

As the formulas all produce quite different results its hard to tell which is the most accurate (as we are missing data on relative humidity, traction surface and ambient temperature amongst others).

However, I think its safe to say at the very least we have the full 475 bhp. My experience at the track suggests its about right when compared to a colleague running a 997.2 GT3.

Nick

Does Porsche know?

aamersa

Of course they know, but they are not very good at communications.

ToyGuyAZ

Several 991GT3's have gone 125-126 in the quarter mile. That's indicative of at 500-510hp pretty easily.

Jimmy-D

^ But keep in mind Porsche has put together a pretty unique package. Meaning, it is how the horsepower is delivered and when. Plus, you have to factor speed of shifts which knock tenths off the equation. So, I do think 475 may be conservative but there are still factors that Porsche did in the 991 that helps it's straight line speed. actually, this car has me a little stumped. There are few cars you can actually compare this to. And I am not talking about the raw performance numbers. It is just how this car gets there which is fascinating.

24Chromium

frayed

X991

ToyGuyAZ

It's not rocket science and they aren't doing anything new. DCT's have been around for years and power is power. The hp rating just happens to be underrated from the factory. The only thing the car does for the driver in a quarter mile situation is allows for maximum trap speeds very easily with repeatable launch control and shifting. The horsepower/weight/trap speed figures are usually pretty accurate given an accurate trap speed and weight

quickshift

Don't forget the gearing, good bit lower.

Drifting

It feels like 500.

Remember Car and Driver timed the GT3 0-60 in 3 seconds flat (as in 3.0 seconds), and the quarter mile in 11.2 seconds at 126MPH.

When guys ask me how much HP the car has, I just say 500.

Jimmy-D

^ One thing for certain; - How many cars with 475 hp weighing around 3300 lbs can do the quarter mile in 3.0??

I kind of understand what ToyGuyAZ is conveying.