Electric turbo
Discussion
Does anyone know why we don't have electrically powered forced induction aids? It strikes me that in its simplest form an electrical blower pumping compressed air directly into the intake manifold could eliminate turbo lag, while not introducing the cranking losses inherant with a supercharger.
I suspect it would be somewhat cheaper to manufacture than a 'normal' turbo / supercharger too....
Is this a great example of thinking 'outside of the box' or am I being dumb? I need to know...
I suspect it would be somewhat cheaper to manufacture than a 'normal' turbo / supercharger too....
Is this a great example of thinking 'outside of the box' or am I being dumb? I need to know...
Guy Humpage said:
I read in Autosport last year (or the year before) about a chap who built a hillclimb car with a Cossie engine which had a seperate turbine engine which powered the turbo.
This sounds like the hyperbar engine built by (I think) Nick Mann? Basically the dump valve blew into a burner where fuel was injected and burnt and fed into the exhaust upstream of the turbo. Meant the turbo ran continuously at any boost you wanted. I think he ran at extremely high boost, 11 bar springs to mind!
This sounds like the hyperbar engine built by (I think) Nick Mann? Basically the dump valve blew into a burner where fuel was injected and burnt and fed into the exhaust upstream of the turbo. Meant the turbo ran continuously at any boost you wanted. I think he ran at extremely high boost, 11 bar springs to mind!
11 bar boost!
Bloody hell! The turbo F1 cars only ran 4!!! That must have flown!!!! E-charging is something most of the major manufacturers are working on at the moment. The idea is to have an ordinary turbo (driven by exhaust gas) but to have an alternator/battery driven electric motor that can help it out when it needs it ie. to illiminate lag and crappy low revs performance.
Expect to see them in production on Diesels at least in the next few years.
Expect to see them in production on Diesels at least in the next few years.
GreenV8S saidThis sounds like the hyperbar engine built by (I think) Nick Mann? Basically the dump valve blew into a burner where fuel was injected and burnt and fed into the exhaust upstream of the turbo. Meant the turbo ran continuously at any boost you wanted. I think he ran at extremely high boost, 11 bar springs to mind!
Isn't he the same bloke who used to run a Morris Minor with a mid-mounted Rover V8 very successfully? He certainly likes to do things a bit differently it would seem!
Must admit I'm not sure it was eleven bar, it might only have been 110 psi or something, I just remember it seemed a hell of a lot compared to the 1-2 bar I've come across elsewhere. The engine underneath this was quite exceptional as I recall, I guess it would have to be to take this sort of boost. What boost do top fuel dragsters run btw?
according to this page : Top Fuel Dragster they run about 54 psi...
>> Edited by Fatboy on Thursday 20th March 16:47
>> Edited by Fatboy on Thursday 20th March 16:47
>> Edited by Fatboy on Thursday 20th March 16:47
>> Edited by Fatboy on Thursday 20th March 16:47
Sounds like it'd be a bit counter-productive to me: consider an air compressor such as you'd use for spraying paint. You have a big motor driving a compressing piston via a reduction belt drive. There's usually an unloader valve to disconnect the reservoir from the cylinder as the motor starts in order to get it moving. That tells you something of the forces involved (OK, you wouldn't have a reservoir as such on a car). Bear in mind this is a 240V AC motor; if you make it a 12V DC motor the current drain would multiply several times. Where's the juice coming from? Er... the car alternator. Ever turned your headlamps on and heard the engine note change? That's due to the electromagnetic retardation effect as the alternator gets loaded up by the electrical system.
So... you have your motor-driven air compressor. You put your foot down, the motor comes on load as the air gets compressed, loads the alternator which attempts to slow the engine down. Hmmm.
I can see the point made about improving turbo-lag, but unless you could make the turbo selective (engage and disengage by an electromagnetic cluch, say... oh, but that in itself would load the electrical system !
, it would have to be making some pretty spectacular contribution to the overall power delivery to make it really worthwhile.
Regards Ian
So... you have your motor-driven air compressor. You put your foot down, the motor comes on load as the air gets compressed, loads the alternator which attempts to slow the engine down. Hmmm.
I can see the point made about improving turbo-lag, but unless you could make the turbo selective (engage and disengage by an electromagnetic cluch, say... oh, but that in itself would load the electrical system !
, it would have to be making some pretty spectacular contribution to the overall power delivery to make it really worthwhile. Regards Ian
Well it worked on my lawnmower
I got my sisters old hairdryer, removed the heating element, wired up a potentiometer to vary the hairdryers speed, took off the air filter assembly, put a pvc funnel onto the carburettor, and sat the hairdryer in it.
Start up the mower, flick the switch, turn the knob and BOOOOOST! Simply twisting the knob was like instant throttle. Imagine this on a gokart!
The motor was never the same again
I got my sisters old hairdryer, removed the heating element, wired up a potentiometer to vary the hairdryers speed, took off the air filter assembly, put a pvc funnel onto the carburettor, and sat the hairdryer in it.
Start up the mower, flick the switch, turn the knob and BOOOOOST! Simply twisting the knob was like instant throttle. Imagine this on a gokart!
The motor was never the same again
What was the hairdryer motor powered by?
Pelo said: Well it worked on my lawnmower
I got my sisters old hairdryer, removed the heating element, wired up a potentiometer to vary the hairdryers speed, took off the air filter assembly, put a pvc funnel onto the carburettor, and sat the hairdryer in it.
Start up the mower, flick the switch, turn the knob and BOOOOOST! Simply twisting the knob was like instant throttle. Imagine this on a gokart!
The motor was never the same again
mrsd said: Wouldn't you be getting power losses twice over and having to house both a huge alternator and an airpump ? Why not just have an airpump running direct from the drivebelt - ie. a supercharger.
Sounds good to me
I suppose you could have a large battery, not connected to the alternator and just switch on the turbo when you want it, and recharge the battery over night?
There is actually an electric turbo on the market.
Cant remember who its made by at the moment tho, but it fits most cars and gives a modest 15% power increase on a standard unmodded motor.
The test car was if i remember correctly a mitsubishi charisma...supposed to be a part replacement fitted in the airbox..talk bout stealth!
Cant remember who its made by at the moment tho, but it fits most cars and gives a modest 15% power increase on a standard unmodded motor.
The test car was if i remember correctly a mitsubishi charisma...supposed to be a part replacement fitted in the airbox..talk bout stealth!
No no no no you've got this all wrong.
You don't want an electric motor turning it, what you want is an anti lag supercharger type system.
Let me explain. At low revs (when the turbo is off boost) you drive the compressor using shaft power. When the turbne of the turbo spools up and starts to provide the power to run the compressor you disconnect the shaft power from the engine.
You could do this with an elecromagnetic clutch.
Now I'm not sure exactly how these work but I know that Merc have one in one of their V6's. Although on this car its only used to bring the supercharger in and out of operation. It doesn't use the turbos as well.
The merc uses the electromagnetic clutch to ensure that the 'charger only comes online when you need the extra power. So you get the fuel economy of a normal car when you're off boost. I remember seeing it in a magazine somewhere but I can't remember where.
Andy
You don't want an electric motor turning it, what you want is an anti lag supercharger type system.
Let me explain. At low revs (when the turbo is off boost) you drive the compressor using shaft power. When the turbne of the turbo spools up and starts to provide the power to run the compressor you disconnect the shaft power from the engine.
You could do this with an elecromagnetic clutch.
Now I'm not sure exactly how these work but I know that Merc have one in one of their V6's. Although on this car its only used to bring the supercharger in and out of operation. It doesn't use the turbos as well.
The merc uses the electromagnetic clutch to ensure that the 'charger only comes online when you need the extra power. So you get the fuel economy of a normal car when you're off boost. I remember seeing it in a magazine somewhere but I can't remember where.
Andy
andytk said: Now I'm not sure exactly how these work but I know that Merc have one in one of their V6's. Although on this car its only used to bring the supercharger in and out of operation. It doesn't use the turbos as well.
The merc uses the electromagnetic clutch to ensure that the 'charger only comes online when you need the extra power. So you get the fuel economy of a normal car when you're off boost
The old Mk1 MR2's had a magnetic clutch on the supercharged versions. It avoids the power losses of driving the supercharger at low engine speeds/part throttle when it wouldn't be doing anything anyway, but you'll never get the economy of a N/A engine simply because the compression ratio of a petrol engine using forced induction is that much lower.
The whole point of a turbo is 'something for nothing', anyway. ie all those exhaust gasses get put to good use. If you have to put energy in, might as well be with a supercharger belt driven off the engine.
Maybe an elastic band powered turbo would be good, or get a few hamsters in the back spinning up the turbine I can see it now, the Volvo S40 HamsterTurbo 
Otherwise, what about a big bottle of compressed air? You know, diver's bottle. Assuming weight wasn't a problem it could give you A LOT of boost for a limited period
ie the energy is put into the charge beforehand. If you're doing bottles, makes as much sense to go for NOs, though, eh?
>> Edited by domster on Wednesday 26th March 17:02
Maybe an elastic band powered turbo would be good, or get a few hamsters in the back spinning up the turbine
I can see it now, the Volvo S40 HamsterTurbo Otherwise, what about a big bottle of compressed air? You know, diver's bottle. Assuming weight wasn't a problem it could give you A LOT of boost for a limited period
ie the energy is put into the charge beforehand. If you're doing bottles, makes as much sense to go for NOs, though, eh? >> Edited by domster on Wednesday 26th March 17:02
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