Weight and Horsepower questions...

Mooso, Mike Dailey's site http://www.panteraplace.com/ list all the basic specifications under Technical specifications, very useful website that I'm sure other members would agree with. Haven't seen any skid pad figure though.

Michael,

unless the magazines pull a motor to test it on an engine dyno, they have only 3 ways to quote bhp figures, (1) on a chassis dyno, (2) to extrapolate the figure using acceleration data or (3) to simply quote the manufacturer's claimed bhp. To my knowledge, they do the latter.

I have access to old magazine reports at home I can post some data later this evening. I believe they do include skid pad results. When comparing skid pad results, you must observe the diameter of the skid pad, if they aren't identicle, then the results aren't comparable.

regarding weight, many magazines simply quoted the manufacturer's claimed weight, Road & Track actually measured it.

Vehicles do 3 things, accelerate, corner & decelerate. Many factors affect the vehicle's ability to perform these tasks, not just bhp & weight. Rather than focus on the power & weight of the vehicle, I would suggest you compare 0 to 60 mph acceleration times, 80 to 0 braking distances and the skid pad results.

Every time you read a 0 to 60 acceleration figure, I would like you to think of a name, Uncle Tom McCahill, the pioneer in automotive journalism who originated the use of this measurement.

your friend on the DTBB

Michael,

the push button that R&T tested in the September 1971 issue had a curb weight of 3155 pounds. They posted a 0 to 60mph time of 6.8 seconds, which was about a second slower than every other publication was publishing.

The "L" that Motor Trend tested in September 1973 had a curb weight of 3580 pounds, 20 pounds heavier than the big block Corvette it was being compared to. This figure seems very high, I think it is bogus.

In August 1984 Car and Driver tested a GT5, riding on Pirelli P7s, at 0.89g on a 282 foot diameter skid pad. In June of that year R&T teste the same car. They published no skid pad data, but the 700 ft slalom was clocked at 62.4 mph. C&D listed the curb weight of that GT5 as 3268 pounds, R&T did not measure the car's weight, only "estimating" the weight at 3250. Car and Driver was able to manage 5.2 seconds from 0 to 60 mph, R&T 5.5 seconds.

Curb weight, by the way, means the car is filled with all fluids, a 1/2 tank of fuel and no driver or passenger.

your friend on the DTBB

Thanks, George! It looks like the GT5 is an impressive performer. Even by today's standards, those are good numbers. Just tires and tweaks away from excellent.
So, I understand that if a magazine wants their own HP numbers, they're going to get rear wheel HP from a Dyno run. But when a manufacturer quotes HP, are there any standards? I recall that many years ago they were required by SAE (I think) to hook up "normal" items like air cleaners, alternators and AC pumps when doing dyno pulls, but I assumed those were still flywheel numbers...not rear wheel numbers from a complete car.
I was just wondering if new manufacturers HP quotes are still "engine stand" pulls or are they rear wheel pulls from a complete production model car?
Lots of high end cars hover around 500HP these days. A Cleveland has that potential and more. I just wanted to know where the factory numbers came from and how to compare them to some of the Cleveland dyno charts I've seen.
Thanks for the info!
Mooso.

Michael,

the manufacturers publish engine dyno numbers (flywheel horsepower), not rear wheel numbers. In the US, the SAE specifies "Net BHP", which as you wrote, means the normal accessories are installed and operating. The Euro manufacturers conmply to a DIN specification, which runs about 10% higher than SAE numbers. The Italians generally just pad their numbers 10% higher than their competitors.

Your friend on the DTBB

My owner manual for my 74 lists curb weights as follows: Pantera L 2998 lbs. Pantera GTS 3042 lbs. Pantera GT5 3042 lbs. Chuck

I weighed my 1971 Pantera (ser no. 1386). With a full tank of gas, 9 quarts of oil and myself (180lbs) and son (150lbs) in the car it came in at 3500lbs.

Thanks for the info guys. I was suspicious that the manufacturers' HP numbers were flywheel numbers, but wanted to get an expert to confirm it. Who better than the "director" his-self!
Sneaky Euros. Cheating on the numbers?! Who would have believed it.
Now when I see a massaged Cleveland pulling 500HP at the flywheel...and the latest BMW multi-valve, overhead cam, sequential turbo, variable timing, direct injected, computer managed marvel pulling 486HP...I'll know which one to be impressed with.
Ughh...Pushrods...Good!!
Mooso.

Here's the specs of the GT5-S. I reduced it as much as I could so that it would still be legible. I have the original file if anyone wants a higher resolution one...

Article taken without permission from Autocar 1986 ;-)

p.s. had to reduce the file even further because it exceeded allowed BB capacity. Hope it's legible!

My 72 GT-5 clone weighed exactly 3300 lbs with slightly less than half tank of fuel and no driver. Car has aluminum heads and intake.

Steve