1slow370

the tvs does develop boost a hair faster and harder than the twinscrew units but it's efficiency is nothing like a real twin screw. It takes more power to drive lowering the net output and requires a more sophisticated intercooler to get the temps down due to lower adiabatic efficiency. It's a huge improvement over your standerd roots type but it still isn't twinscrew, it's just a blower not a compressor. Blowers have symmetrical intermeshing rotors like two gears running against eachother. the air is trapped between the teeth of each rotor pushed around the outside of the rotor against the case and shoved below it. Superchargers spin the opposite direction of what most people think they should kinda like this (tOOt) the air goes around the rotors from the top of the t's out the bottom. Twinscrew blowers turn in the same manner but have crucial differences, the rotors are opposing cones set up so that air enters at the fat end of the female cone and is compressed by the male cone into a progressively smaller space until it exits the blower. This actually produces a compression ratio in the blower. My work uses a huge 9 liter version to run all of the pneumatic lines in the shop (well we rent it when our busta 100 yr old two stages are broken). These differences in basic design are what produce the difference in performance. The twinscrew type is always compressing the are despite what happens afterward. Blowers only form boost when they push more air then the engine needs. The heat of compression is actually formed in the manifoldbecause that is where the compression takes place. In a twin screw the heat is released inside the blower and leaks into the manifold with the air charge. Twinscrews need to be built to handle the heat they produce, the rotor design is FAR more complex to machine (I'm a machinist and it makes me wonder how the hell they do it), but in the end it releases less heat into the manifold and due to design creates less in the first place.

Technical issues aside look at the vehicles they go in twin screw: Some AMG cars, ford GT40, tvs:GM four poppers and the vette ZR-1(GM has a purchase agreement for the TVS technology). It's a price thing if you want to pay 50% more and don't care so long as it is the pinnacle of performance with real world gains you buy screw not roots. There is a TVS Based four lobber in the new gt500, the best upgrade for it right now is a brand new whipple twinscrew (kenne bell is coming out with a dedicated unit for it as well). With the same boost you make more power with a twinscrew and it is delivered in a flatter manner.

Oh and EATON makes the majority of ROOTS BLOWERS not TWINSCREW COMPRESSORS