Oh, Nightfire, you force my hand.
You PD guys preach nothing but dyno graphs and "power under the curve”…
Whether you agree with it or not, it is a FACT that the car that puts down the greatest average torque to the ground WILL win a race. Period. That’s math. No arguing that. And the car with the greatest power under the curve will put down the greatest average torque to the ground. Another FACT.
....yet they are consistently outperformed at the track by centri…
Complete, utter nonsense. Not only does every bit of personal experience I have disagree with this, but every OEM on the planet disagrees with it as well. If a centrifugal supercharger really did perform as well, you’d see them on OEM equipped cars. Newsflash: they aren’t.
It should also be telling when you look at the aftermarket options for newer 5.0s and GT500s, as well as what owners are actually buying. There’s all of about 2 options for a centri blower, with upwards of a dozen options for PD blowers. And, to date, I have not seen ONE 2011+ car with a centri blower on it. At the track, on the street, at a cruise-in, dyno day, etc. Not ONE. Have seen countless ones with TVS’s, Kenne Bells, or Whipples.
Now you’re actually make some sense. The very best performing cars at the track on any given day I go are usually well set-up turbo cars. Their downfall is usually the cost and complexity of the system and tuning. But overcome that, and turbo cars usually run very strong.
It reminds me of the old saying:
A positive displacement supercharger gives low rpm torque, but robs crank horsepower.
A turbocharger doesn't rob crank horsepower, but doesn't give low rpm torque.
A centrifugal supercharger doesn't give low rpm torque AND robs crank horsepower.
Hell, I run 0.4 slower than a 2012 GT500 running 650rwhp. The guy can drive like a pro and destroys me out of the hole. I pull slightly in the mid range and freight-train him on the top end.....but he was just too far ahead from the get-go.
You realize that you’re proving my point, right? 4 tenths at your power range is significant, around 5 car lengths. And while he has 100-125 rwhp on you, he also has around 500 pounds on you as well. If a manual transmission car is beating you off the line, especially if you have a converter and built transmission, that should be telling about how much more torque he’s making down low than you are. Even at a relatively significantly power disadvantage, a stalled auto should ALWAYS be quicker off the line than a manual transmission.
Out of curiosity, what are the other numbers comparing the two cars? 60 times, trap speeds?
YOU'LL NEVER GET ME TO BELIEVE YOUR PD-BABBLE SNEAKY! On paper they should win.....but I just never see it.
If you don’t like them, that’s fine. But don’t go giving your opinions as fact to someone who doesn’t know any better.
.....and don't even get me started on the heat-soak issues.
More nonsense. The water-meth on my NON-intercooled Heaton cools it down from scalding hot in a matter of a second or two. And then it stays cool for several minutes following. I’ve done runs at the track from return lane straight to back to the staging box, and rarely do I lose more than a tenth or two. And for the cars with an air-to-water intercooler, they do just fine relatively speaking on cooling the ACTs down. Is it true that you’ll lose power on back-to-back runs with no cool down? Absolutely. But you’ll find that to be true on any car.
Centri and turbo setups avoid this by utilizing an air-to-air intercooler which significantly reduces the temp of the air entering the engine.
There is nothing wrong with air-to-air intercoolers, but don’t be fooled into thinking that air-to-water intercoolers are inferior. Go to a track, and look at a 1500+ horsepower X275 or 10.5 car and find one running an air-to-air intercooler. Pro-tip: don’t waste your time looking, you won’t find one. They’re all air-to-water. The reason? Because you can actually cool the air to below ambient temps. With an air-to-air, even at 100% efficiency, you can’t get it below ambient. So on a 90 degree race day, you’re looking at 90 degree ACTs if the intercooler is perfect (which it’s not). But with ice water in an air-to-water, you can get those temps down well in to the 50s or even 40s on a hot day. Some smart folks out there even invented a system for the 03/04 Cobras that pumps the intercooler fluid through the air conditioner so that you cool the water way down, and it actually works very well, especially on the street where you’re running the A/C anyway.
So bottom line: PD >>> centrifugal.
Nightfire, don’t take any of this personally. I need to have something to do during my off-time at work.