Is Horsepower Overrated? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Topless · 10-21-2007, 04:03 PM

I just watched the America Le Mans series final at Laguna Seca. The Audi R10 won the race and the overall. Great racing. In second was the Penske Porsche RS Spyder just seconds behind. While the Audi was faster in the straights the Porsche laid down faster best lap times all season.

Compare these two cars:

Audi R10 2040 lbs, approx. 700hp, approx. 1000lbs torque, lbs/hp 2.9

Porsche RS 1708 lbs, approx. 500hp, approx. 500lbs torque, lbs/hp 3.4

That is a HUGE difference in power. Why didn't Audi run away from everyone? Why did Porsche turn faster lap times? Are the Penske drivers that good? What gives?

10-21-2007, 04:13 PM

Driver skill. Better braking, Taking more speed into and out of the curves.

blue2000s · 10-21-2007, 04:22 PM

I wouldn't say power is overrated, I'd say low weight is underrated. Everything that involves acceleration or deceleration (in any direction) is improved with lower weight.

Topless · 10-21-2007, 05:00 PM

Interesting.

10-21-2007, 05:12 PM

Another way to look at it:

Topless · 10-22-2007, 06:34 AM

So Newtons law of motion tells us that the Audi will need an extra 200hp an an extra 500lbs of torque to overcome a 330 lb weight difference? Wow. That seems like a lot.

racer_d · 10-22-2007, 06:46 AM

Quote:

Originally Posted by Topless

I just watched the America Le Mans series final at Laguna Seca. The Audi R10 won the race and the overall. Great racing. In second was the Penske Porsche RS Spyder just seconds behind. While the Audi was faster in the straights the Porsche laid down faster best lap times all season.

Compare these two cars:

Audi R10 2040 lbs, approx. 700hp, approx. 1000lbs torque, lbs/hp 2.9

Porsche RS 1708 lbs, approx. 500hp, approx. 500lbs torque, lbs/hp 3.4

That is a HUGE difference in power. Why didn't Audi run away from everyone? Why did Porsche turn faster lap times? Are the Penske drivers that good? What gives?

um.. Porsche did win 7 or so races outright vs the Audis this year.
Weight is critical. When you watch F1, you learn that every gallon of fuel ads several tenths of a second per lap. The audis are already 300lbs heavier without fuel. The key to the Audis is that there incredible Torque allows them to pull away from slow corners quicker. Tight street courses played to the Audis advantage usually. Longer courses with "fast" corners, well, light weight has its advantages.

Of note, at Mosport, the GT3 cars were pulling 150ish at the end of the back straight.. the LMP2 cars, about 170, the LPM1 Audis - close to 185. The extra hp/tq can also come into play when setting up the cars downforce. You can run "more wing" and not give up to much to the LMP2 cars.

Uncle Bob · 10-22-2007, 07:18 AM

The Audi had less fuel at the end as well, allowing it significantly quicker lap times. Did you see the Road America race 2 weeks ago? Basically same scenario.

HB. · 10-22-2007, 07:46 AM

I guess we can all post our theories, but the bottom line is which car came in first and which car came in second...

Honestly, I'd rather be the guy with the heavier car with more horsepower winning the race, then the guy with the lighter car with less horsepower loosing the race.

10-22-2007, 08:04 AM

Like my race car driver friend Ricky Bobby says, "Second place is just the first guy to loose!"

Shake-n-Bake!

Uncle Bob · 10-22-2007, 08:35 AM

Quote:

Originally Posted by HB.

I guess we can all post our theories, but the bottom line is which car came in first and which car came in second...

Honestly, I'd rather be the guy with the heavier car with more horsepower winning the race, then the guy with the lighter car with less horsepower loosing the race.

Factor in that these are endurance races (Road America was Petit Le Mans) and strategy really comes into play.

Topless · 10-22-2007, 08:45 AM

Of course, winning is always best. Performance wise these cars were so very very close. In the last 20 laps at Laguna the Porsche passed the Audi twice in the curves only to be passed again in the straights. As racer_d said the Porsche beat the Audi seven times during the season... An Audi with 40% more HP and 100% more torque. That is a bigger power difference than Boxter S vs GT3. I am still trying to make some sense out of this.

Gary in BR · 10-22-2007, 09:02 AM

Lightweight is why our 200hp boxsters are as much fun as more powerful cars

racer_d · 10-22-2007, 11:55 AM

More importantly, and not touched on, are the regulations of the sanctioning body. No one at ALMS want their "top" class, LMP1, beaten (and beaten consistantly) by the 2nd tier class (LMP2). IIRC, the Porsche faced inlet restrictions to choke down power so that the LMP1 cars would be faster (and possible also weight penalties).

Only at LeMans (I don't think the US ALMS adopted) the fuel restrictions (ie smaller fuel tanks) for Diesels put the real hurt on them. Thus, the inherant advantage at LeMans, and the reasoning behind the Audi Diesel, was greater fuel mileage. The French (the pescarola team) whined to the French orgainizers of the French race, to lobby to change fuel restrictions on the diesels, knowing full well that, given the same size tanks, the diesels could still run slower but win due to fewer fuel stops.

The Audi diesel is a remarkable racing achievement. 1000 ft-lb of torque? 700 (or more) hp? Audi clearly took over where Porsche left off in Dominating long distance races... The R8, R10 (and the interim Bentley (nee audi coupe) have dominated against both strong and weak competition for nearly a decade.

I would love to see Porsche LMP2 RS Spyders run at LeMans. I love the image of Porsche as "giant slayer" as they were in the '50-60s and then as Giants themselves from 1970-1990's.