Centrifugal vs Positive Displacement SC

[serialk11r]

Originally Posted by Tansey86

You cant directly compare to means of forced induction? Pretty sure thats not true

Stop being difficult. All he said was "better" is subjective, and the obvious reasoning is that there are different criteria in which each method is better. And yes you can't directly compare because they have different attributes, each of which has a pretty clear winner.

[Tansey86]

Originally Posted by serialk11r

Stop being difficult. All he said was "better" is subjective, and the obvious reasoning is that there are different criteria in which each method is better. And yes you can't directly compare because they have different attributes, each of which has a pretty clear winner.

Either way I think you'll have a badass machine at your disposal. I guess it all comes down to budget and goals but IN MY OPINION, I prefer and think turbo is better.

[madfast]

Originally Posted by unijabnx2000

http://www.lsxtv.com/news/procharger...-supercharger/

this is a great stepping stone for variable SCs but we need on the fly ratio changes. make no mistake, for an aftermarket product it is great. i just want to see OEMs start using something like this. IMO it would make the turbo obsolete...

Originally Posted by serialk11r

The (slight) issue with this is that you automatically lose 10% drive efficiency or so from the CVT.

perhaps Rotrak's version can be more efficient?

[ame="http://www.youtube.com/watch?v=ihdo78KsMOA"]Variable drive supercharger Rotrak (Part 2) - YouTube[/ame]

The thing is, engines are turning more and more into mild hybrid types and OEMs are working on electric powered turbos (which solve basically all these problems), which are supposedly pretty close to arriving on the market...sure it's not tuner friendly but can you argue with efficiency and great response?

imo electric turbos are a myth. i'll believe it when i see it. more likely than not would be a performance hybrid system where the electric motor "assist" is used at low rpm while a powerful motor with large turbos spool up. that same motor can also be used at high speed as a KERS style boost. this is what i want to see...

[madfast]

Originally Posted by unijabnx2000

you cant directly compare..... didnt you just do that?

no he didnt. u guys dense? he clearly said that turbos and cent SCs are good at different things so you cant really compare them.

[unijabnx2000]

Someone say electric supercharger...

[Braces]

I use my FR-S as a daily driver. I'm looking for a little more power. What is important is reliability with no engine issues. I'm not looking for huge HP. Somewhere between 250-300. Again ... reliability is the theme. Do I get the centrifugal or turbo?

Thanks

[FreshFRS]

Originally Posted by Braces

I use my FR-S as a daily driver. I'm looking for a little more power. What is important is reliability with no engine issues. I'm not looking for huge HP. Somewhere between 250-300. Again ... reliability is the theme. Do I get the centrifugal or turbo?

Thanks

centrifugal would be your best bet. super easy on parts and should meet your power goals.

[serialk11r]

Originally Posted by madfast

perhaps Rotrak's version can be more efficient?

imo electric turbos are a myth. i'll believe it when i see it. more likely than not would be a performance hybrid system where the electric motor "assist" is used at low rpm while a powerful motor with large turbos spool up. that same motor can also be used at high speed as a KERS style boost. this is what i want to see...

All mechanical CVTs inherently have some extra frictional losses since there is some sliding action going on due to a small variance in speeds. So I don't know how efficient the best CVTs are but it's not as good as the good ole discrete gears.

The thing stopping us from having electric turbos is the 12V system. You can't have high power density electric motors on 12V. That's why I think it's going to be a post-hybridization thing, as alternators and starters are ditched for flywheel mounted generators, belt driven accessories are ditched for electrically driven ones, and 12V is relegated to mundane things like switches, lights, etc., the infrastructure necessary to pipe the large amounts of electrical power that a supercharger would require would start to exist. At the end of the day efficiency would be perhaps the same as a CVT but it would become a modular electric component rather than a mechanical add on.

[madfast]

Originally Posted by serialk11r

The thing stopping us from having electric turbos is the 12V system. You can't have high power density electric motors on 12V. That's why I think it's going to be a post-hybridization thing, as alternators and starters are ditched for flywheel mounted generators, belt driven accessories are ditched for electrically driven ones, and 12V is relegated to mundane things like switches, lights, etc., the infrastructure necessary to pipe the large amounts of electrical power that a supercharger would require would start to exist. At the end of the day efficiency would be perhaps the same as a CVT but it would become a modular electric component rather than a mechanical add on.

but why wouldnt you use whatever energy you generate to power a motor to directly drive the wheels? it makes no sense to use that energy to power an e-turbo instead of a motor. the germans with their single motor ZF hybrids are finding this out the hard way. their hybrids SUCK. toyota, ford, gm, and now honda are all aboard the 2 motor system. that's the future imo. not just for economy cars but sports cars as well. i keep thinking about a hybrid system like the one in the GS450h. that car gets 29/34/31 with a 4200 lbs car. i can only imagine what that system can do in a smaller, light weight car with a slightly larger, more energy dense li-ion battery...

[serialk11r]

Originally Posted by madfast

but why wouldnt you use whatever energy you generate to power a motor to directly drive the wheels? it makes no sense to use that energy to power an e-turbo instead of a motor. the germans with their single motor ZF hybrids are finding this out the hard way. their hybrids SUCK. toyota, ford, gm, and now honda are all aboard the 2 motor system. that's the future imo. not just for economy cars but sports cars as well. i keep thinking about a hybrid system like the one in the GS450h. that car gets 29/34/31 with a 4200 lbs car. i can only imagine what that system can do in a smaller, light weight car with a slightly larger, more energy dense li-ion battery...

Because investing that energy into moar air gives moar power. Same reason why you use the energy from the engine to power a supercharger, instead of the wheels.

I don't know about 2 motor system, for performance applications yes, but depending on the setup they could just ditch one and save the money (and lose some acceleration). Hybrid cars are already pushing it when it comes to affordability.

[arghx7]

serialk11r is correct. Without a high voltage circuit in the vehicle, you need very large wires and lots of current to drive electric accessories (including electric-powered forced induction).