Quote:
Originally Posted by CSG Mike
It's also why an automatic Porsche Turbo is faster than the manual; the turbos don't need to respool between shifts.
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Porsche isn't a good comparison for that as with their variable technology it would be a moot point. The 911 doesn't come in stick anymore anyway as well. It's also ignoring that they use dual clutch gearboxes which have lower losses than a conventional auto and can shift faster than you can blink. Even if boost didn't drop on shifts with a stick, you'd still lose.
But yes, on an old school journal bearing turbo with a normal conventional auto and stick, the auto will usually win so long as the drivetrain loss isn't excessive.
Quote:
Originally Posted by TurboBRZ
I'm just curious why you would be willing to spend so much money for such little hp gain?
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Have to see the dyno sheets, the main gain is low end and in the factory dip. It's also being continuously developed and getting better.
Quote:
Originally Posted by TurboBRZ
Off the line would imply drag racing, in which case most drivers rev their engines up to 4-5k RPM's to make sure boost is there when they launch.
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RPM =/= boost with a turbo. If you want boost off the line, you need load (building boost with the torque converter on an auto) or a 2-step.
Quote:
Originally Posted by TurboBRZ
This is only true if the turbo manifold runners and collector are smaller than the stock header, which they are not. The stock exhaust is 2" and I have a 2" outlet on the back wheel of my turbo. Plus my runners are slightly larger on the manifold.
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This alone means you don't have the slightest clue about what you're talking about. Turbos are a restriction (so much so that they can seriously quiet down a car) and if they did flow like a straight pipe, that would in essence be breaking the laws of physics.
The main reason turbos are better than superchargers is that they're low maintenance (they use the same oil as the engine) and they're more efficient than superchargers (though a Rotrex gets damn close). They're also in essence a "displacement on demand" as load = boost = more power. This is why the OEM's like them because they can have the passing ability of a larger engine, with good fuel economy.
Quote:
Originally Posted by TurboBRZ
You assume I ever let my foot off the gas to go from 6k to 5k rpm's... I don't. I've run many tracks, drifted with the pros on pro courses in Japan, and maintaining your throttle position is key to any type of performance driving. If you're letting your RPM's fall without keeping your foot on the accelerator then of course you're going to get lag in any situation. There is always a delayed response to your foot.
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Bypass/blowoff valve doesn't only work when the throttle is closed, it also kicks in at smaller pressure differential changes (like if you let off the throttle). Pushing the clutch is removes the load on the engine so it's also going to cut boost.
If you've ever driven a car with a loudish BOV you'd know all this...