Recently, a company called Anatov has produced a small two-speed transmisison designed to go on a centrifugal-style supercharger. The goal is the same as when you attatch a transmission to an engine, you're trying to control the speed. This means that, provided the transmission has the proper gear ratios, you can take a centrifugal supercharger and set the boost output to an extremely high level and not have to worry about it building boost by the sqaure and achieving it only beyond a certain set RPM. The attatched transmision would be geared so that the engine, at idle, would spin the supercharger fast enough to produce the desired boost. A brilliant idea on paper, but it got me thinking. A transmission has to shift gears, and to do so, I'm guessing there's a momentary complete loss of power to the supercharger. This I thought, regardless of how short of a time it takes, would cause a significant drop in boost levels, so that when it shifted from gear 1 to gear 2 it would have to re-build the boost it lost. And so here is my question to you all. Would it be worth it? A momentary complete loss of boost, which would happen in first gear as the engine's RPM became high enough to sustain the preset boost in second gear, for the ability to launch of the line with 25+ PSI being fed to the engine?

As well, if the set boost level is large enough to where only the extremely high RPM range is capable of sustaining it while the SC tranny is in second gear, every time you shifted the engine's transmission and dropped the RPM, the SC tranny would also have to shift down to the firstr gear to sustain your boost. The SC tranny's downshift would not be a problem because it would occur at the same time as the engine tranny's upshift and likely be completed the same time the upshift was completed, however, that means in every single gear you would be dealing with the same momentary loss in power to the SC somewhere in the RPM range. Like I said though, this would only happen if the boost levels were set high enough. So it's possible that this supercharger two-speed transmission would not be a logical choice for high-boost.

On top of all this the predicted cost is between 2,000 and 4,000.....euros.

Discuss?

 

On another note, does anyone know if changing the gear ratio on the supercharger to allow more boost at idle would increase the parasitic loss? Perhaps to an inefficient level for higher boost race applications?

 

well, the transmission itself would probably cause more less in itself, over the differenve between the 2 gears, but i'd say, like i have before, CVT all the way, but we havn't gotten that far advanced on them to handle power and stuff like that, but i don't think it'd be practical, and like you said, that momentary loss in power would put the car on its face and then pick it up, and on the track i don't know how much fun that would be, plus in high HP apps, you launch at such a high RPM your probably in boost anyways...yo no se

 

there is no boost at idle, if you did you'd have problems.

But, changing the pulley ratio on a SC can allow for more boost sooner AND more boost up high. If you can fuel/handle the boost, then its a good thing. Also, yes the parasitic drag does increase the faster and harder that the SC has to work AND it highly depends on the particular SC itself on where the mechanical redline is and how shitty the efficiency becomes.

 

think its a good idea, but it fails.

 

With the Anatox transmission, you'd have boost at idle engine speeds unless it had a neutral it sat in while idling. The idea behind the transmission is obtaining boost down low without having to deal with surpassing the supercharger's maximum speed as your engine's RPM climb. That's why the second gear is there, it prevents that. And I understand parasitic drag increases as a SC spins faster and works harder, but I'd like to know if the parasitic loss would be greater than normal while the Anatov transmission was in first gear. I thought about it like a bike. My peddling represents engine speed and the speed of the rear wheel if the speed of the supercharger. If I want to increase the speed of the rear wheel on a bike without changing the speed of my peddling I'd change gears. I know that when I do that it becomes harder to peddle at the same speed and requires more energy. That's my empirical evidence for thinking that the supercharger in a lower gear would also require more power from the engine to run. Meaning that for those who wanted to run relatively high boost levels, the parasitic loss on the engine may become to great to do so with the transmission.

 

without numbers to calculate coefficients, this thread is useless.

 

I think planetary gearsets on turbos would render superchargers 100% useless rather than just 70%

Instead, I'll stick with VGT's