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Electric Supercharger
Badger_McLetcher - 1/10/10 at 09:25 PM

This link makes an interesting read, apparently via the use of an electric supercharger (amongst a lot of other tech) apparently this firm has managed to reduce C02 emissions to that of a diesel.
Also a not unhealthy 400 Nm of torque!

[Edited on 1/10/10 by Badger_McLetcher]


flak monkey - 1/10/10 at 09:32 PM

We did some development work on some electric superchargers when I was at uni.

The only issue with them is the huge amount of power they consume, to get a good benefit (boost!) you need to run another alternator just for the charger (they pull around 40A-60A to enerate any significatn level of boost)


dinosaurjuice - 1/10/10 at 09:35 PM

if you calculate the power going down the shaft of a turbo its huge. the complexity and bulk of using an electrical system is just a bit to pointless IMO. if people really care about the environment, they cycle to work


MikeR - 1/10/10 at 09:51 PM

random (i've had a drink) thought.

Could you not use an electric motor on a supercharger to help get round anti lag?

I'm thinking when you lift off the throttle to change gear the electric motor spins up to keep the turbo spinning along with having the waste gate open (so no pressure). Then as you re-engage the engine the waste gate closes, the electric motor rapidly runs out of torque to power the turbo but at the same time the engine gasses catch up. It won't be perfect as i'd expect there still to be a dip in turbo spindle speed ...... but would it help????


MikeRJ - 2/10/10 at 08:36 AM

quote:
Originally posted by MikeR
I'm thinking when you lift off the throttle to change gear the electric motor spins up to keep the turbo spinning along with having the waste gate open


I'm certain this has been tried and/or is in development but there are always practical details which make things difficult e.g. how do you attach a motor to something spinning at 100k+ RPM without it causing any drag when the motor isn't engaged, and also survives turbo temperatures.


dan8400 - 2/10/10 at 09:12 AM

Isnt that what a dump valve does?? Leave the turbo in free-fall (as it were) whilst you change gear... then its spinning when you let the clutch out and throttle up??

Dan


tegwin - 2/10/10 at 09:20 AM

VW got round the "lag" issue by bolting a turbo and a supercharger together...

Low RPM boost from S-C, then high rpm boost from turbo...


MakeEverything - 2/10/10 at 09:56 AM

quote:
Originally posted by dan8400
Isnt that what a dump valve does?? Leave the turbo in free-fall (as it were) whilst you change gear... then its spinning when you let the clutch out and throttle up??

Dan


No, a dump valve depressurises the system when the throttle body closes, in order to protect the turbo. The turbo is still being spun by the exhaust gases, so it never reaches a "Free Fall" effect until the engine is turned off.


Confused but excited. - 2/10/10 at 12:19 PM

quote:
Originally posted by dinosaurjuice
if you calculate the power going down the shaft of a turbo its huge. the complexity and bulk of using an electrical system is just a bit to pointless IMO. if people really care about the environment, they cycle to work


We all do, that's why we all use the Otto cycle.


dinosaurjuice - 2/10/10 at 12:51 PM

quote:
Originally posted by Confused but excited.
quote:
Originally posted by dinosaurjuice
if you calculate the power going down the shaft of a turbo its huge. the complexity and bulk of using an electrical system is just a bit to pointless IMO. if people really care about the environment, they cycle to work


We all do, that's why we all use the Otto cycle.



JoelP - 2/10/10 at 06:04 PM

quote:
Originally posted by MakeEverything
quote:
Originally posted by dan8400
Isnt that what a dump valve does?? Leave the turbo in free-fall (as it were) whilst you change gear... then its spinning when you let the clutch out and throttle up??

Dan


No, a dump valve depressurises the system when the throttle body closes, in order to protect the turbo. The turbo is still being spun by the exhaust gases, so it never reaches a "Free Fall" effect until the engine is turned off.


I think dan is closer IMHO. When the throttle closes during a gear change, flow of gas is reduced/halted in both intake and exhaust. The pressurised gas between the turbo and the throttle makes the turbo stall. By letting it out of a dump valve, the turbo will keep spinning due to its own momentum, and thus repressurise faster once you get back on the gas. Thats how i see it anyway.