Good idea or a complete lack of mechanical knowlege
Discussion
Manufacturers seem to be moving to turbos to get the fuel economy figures without losing the power. I am not a big fan of forced induction based on experience (despite loving my supercharged V8 SLK).
I will start with a slightly clichéd description of the options at the moment.
Turbo chargers = good power, good economy, driving experience compromised through lag
Super charging = good power, constant mechanical drag effecting economy, good driving experience
Natural Aspiration = okay power, poorer economy, best engine response
Now imagine having an 'always on' turbo charged engine. Still the good economy and power but with normally aspirated like engine response.
I know Lancia and VW have done supercharged and turbocharged engine but this is a very mechanically complex system with lots of extra gubbins to fit into the engine bay.
What about this then - fit an electric motor into the turbo charger. The electric motor keeps the turbo spinning while it is 'off boost' and can be switched off once the turbo is up to speed. Less weight and complexity that a supercharger and wouldn't need massive batteries (weight) as it would only need to work at low revs. It could even recharge on overrun.
Any engineers want to shoot this idea down before I run off to the patent office?
I will start with a slightly clichéd description of the options at the moment.
Turbo chargers = good power, good economy, driving experience compromised through lag
Super charging = good power, constant mechanical drag effecting economy, good driving experience
Natural Aspiration = okay power, poorer economy, best engine response
Now imagine having an 'always on' turbo charged engine. Still the good economy and power but with normally aspirated like engine response.
I know Lancia and VW have done supercharged and turbocharged engine but this is a very mechanically complex system with lots of extra gubbins to fit into the engine bay.
What about this then - fit an electric motor into the turbo charger. The electric motor keeps the turbo spinning while it is 'off boost' and can be switched off once the turbo is up to speed. Less weight and complexity that a supercharger and wouldn't need massive batteries (weight) as it would only need to work at low revs. It could even recharge on overrun.
Any engineers want to shoot this idea down before I run off to the patent office?
A colleague of mine developed an electric turbocharger at a previous company - it had an electric motor in it designed to make lag essentially zero. It was very effective but expensive.
F1 engines next year will have a similar concept - the MGU-H is connected to the shaft of the turbine to extract kinetic energy from the turbo when it's not needed (instead of a wastegate) but can also spool the turbo to reduce lag.
F1 engines next year will have a similar concept - the MGU-H is connected to the shaft of the turbine to extract kinetic energy from the turbo when it's not needed (instead of a wastegate) but can also spool the turbo to reduce lag.
What we need is an accumulator, rather than dumping over boost, store it! We used to use similar on 1980's moto-x bikes, "Boost Bottles".
The idea was to store carb back pressure on throttle closing, which would then be released back into the intake when you cracked open the throttle.
Not sure if it made any difference but it sounded good ;-)
The idea was to store carb back pressure on throttle closing, which would then be released back into the intake when you cracked open the throttle.
Not sure if it made any difference but it sounded good ;-)
Smaller turbohargers, from a drivers point of view tend to be "always on", i.e. the boost occurs low in the rev range and fills it in nicely but it doesnt contribute
much at the top end, for example a Saab 2.0 engine made 130 odd bhp, the LPT (Light Pressure Turbo, i.e. small) made 150 bhp but the difference was night and daym, the N/A engine was ok but felt flat in comparison to the rather lovely LPT unit, which, thought the headline figure wasnt that great was a fantastic engine that felt way way quicker than a 15/20 bhp deficit would.
It isnt like Natrually Aspirated engines dont have lag, my 350Z and its predecessor the 944 S2 had large capacity N/A engine but you still need a few revs to get it moving, in reality, lag on modern turbos is a non issue, or means you are in the wrong gear, there are other criticisms but rarely is the "boost threshold" one of them, generally the turbo robs some of the aural purity of an engine note, a lot of turbo units dont like to rev and they aint that economical, lets get that bit right, drive an evo and see how economical it is, power takes energy however you make it.
much at the top end, for example a Saab 2.0 engine made 130 odd bhp, the LPT (Light Pressure Turbo, i.e. small) made 150 bhp but the difference was night and daym, the N/A engine was ok but felt flat in comparison to the rather lovely LPT unit, which, thought the headline figure wasnt that great was a fantastic engine that felt way way quicker than a 15/20 bhp deficit would.
It isnt like Natrually Aspirated engines dont have lag, my 350Z and its predecessor the 944 S2 had large capacity N/A engine but you still need a few revs to get it moving, in reality, lag on modern turbos is a non issue, or means you are in the wrong gear, there are other criticisms but rarely is the "boost threshold" one of them, generally the turbo robs some of the aural purity of an engine note, a lot of turbo units dont like to rev and they aint that economical, lets get that bit right, drive an evo and see how economical it is, power takes energy however you make it.
Your about 15 years too late for the Patent Office i'm afraid!
The current limiting factor (other than the cost of such a device) is that a std 12v automotive electronic system simply cannot supply much more than approx 3kW of power. And a turbo charger will be shifting approx 50kW at peak power!
Plenty of systems have been developed that act as a "fill in" charging system, and hence require a lower maximum power, but even these are only just viable with 12v electrics. The big move will be when the OEM's finally shift to a higher voltage architecture, but this has been talked about for ~15 years now! (although i believe the next BMW 7er is going to have some systems on a 60V bus)
Regarding using boost resevoirs, yup, we've done that too. Back in the early 2000's we used large composite resevoirs "Hidden" behind the bumpers of WRC cars to try to circumvent the 34mm intake restrictor to a degree. Needless to say, this was quickly banned!
The current limiting factor (other than the cost of such a device) is that a std 12v automotive electronic system simply cannot supply much more than approx 3kW of power. And a turbo charger will be shifting approx 50kW at peak power!
Plenty of systems have been developed that act as a "fill in" charging system, and hence require a lower maximum power, but even these are only just viable with 12v electrics. The big move will be when the OEM's finally shift to a higher voltage architecture, but this has been talked about for ~15 years now! (although i believe the next BMW 7er is going to have some systems on a 60V bus)
Regarding using boost resevoirs, yup, we've done that too. Back in the early 2000's we used large composite resevoirs "Hidden" behind the bumpers of WRC cars to try to circumvent the 34mm intake restrictor to a degree. Needless to say, this was quickly banned!
you dont need pops, bangs and a melted exhaust system to have anti lag..
there is another way
http://youtu.be/n_qCd6Lx7pE
there is another way
http://youtu.be/n_qCd6Lx7pE
SystemParanoia said:
you dont need pops, bangs and a melted exhaust system to have anti lag..
there is another way
http://youtu.be/n_qCd6Lx7pE
Oh don't worry, zerolag (or more accurately ex Prodrive WRC antilag) does melt stuff just as well as bang-bang antilag......... ;-)there is another way
http://youtu.be/n_qCd6Lx7pE
I'll have to find out more about the compressors we have at work. Reciprocating compressors but powered by house sized engines. A couple if them are turbo charged straight sixes. What makes them unusual is that the turbo is chain driven (I.e is a supercharger) at lower rpm but then "freewheels" once up to speed
wca said:
What about this then - fit an electric motor into the turbo charger. The electric motor keeps the turbo spinning while it is 'off boost' and can be switched off once the turbo is up to speed. Less weight and complexity that a supercharger and wouldn't need massive batteries (weight) as it would only need to work at low revs. It could even recharge on overrun.
Any engineers want to shoot this idea down before I run off to the patent office?
I think you'll find some manufacturers are or have already developed much higher tech versions of your theory.....Any engineers want to shoot this idea down before I run off to the patent office?
From the blurb on the new BMW M3/M4 engine released recently,
...."In "Sport" and "Sport Plus" settings, the turbochargers are "pre-tensioned," which means that they keep spinning at a high rate of speed even after you have taken your foot off the throttle. This trick ensures ultra-quick response times fully comparable to those of a naturally aspirated engine"......
Don't ask me how BMW have engineeered this though
I'll have to find out more about the compressors we have at work. Reciprocating compressors but powered by house sized engines. A couple if them are turbo charged straight sixes. What makes them unusual is that the turbo is chain driven (I.e is a supercharger) at lower rpm but then "freewheels" once up to speed
Gassing Station | General Gassing | Top of Page | What's New | My Stuff