Quote:
Originally Posted by Ryephile
It's rather surprising how ignorant most aftermarket tuners are of the TVS's unrivaled qualities. Not to totally derail the thread, but personally I feel this would be a fantastic solution for the FA20. TVS's overall efficiency is excellent and they're still an air pusher, so there's no inherent significant parasitic drag from internal compression like a twin-screw or centrifugal. They're really the best overall solution for a supercharged setup, but they're also the most expensive.
That said, a good small turbo setup would give a big flat torque shelf while offering the best fuel economy. You can't have everything; a small turbo setup would trade throttle response and a little bit of lag for better FE and more torque in a less-expensive package over a TVS setup. For most enthusiasts that can't swing a $8k TVS setup, a $4k small turbo solution that gets great fuel economy and is super fun on twisty back roads is hugely attractive.
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Eh, I don't think a small turbo's fuel economy would be any better than a TVS, and it might even be worse if it has the usual spring actuated wastegate rather than an electronically controlled wastegate due to the extra restriction. The turbine is going to be the reason for the power falling off at higher rpm, unless you want to blow off a lot of boost pressure throughout the powerband to flatten the torque curve (could be done to improve reliability, but then again, why not just use a cheap Eaton M62 if you're going to run the turbo so inefficiently).
It's too bad that the smaller TVS units are impossible to find. If they don't hurry up, variable speed centrifugal chargers might take off and nix any chance they had, they have to work at taking away market share from turbos anyhow. Truth be told, the 5th gen M45 and M24 are pretty efficient and are actually better suited for low boost than the TVS chargers in some situations (though the TVS still has packaging/mass advantages), someone should try strapping an M45 to the FA20, running the M45 at max speed will give maybe a 25% bump in power everywhere and that would represent a very efficient usage of the supercharger, although you won't be able to just swap pulleys if you're not happy with the power.