when he was talking about his collection of Radial Aircraft engines. Why have I never heard of an automotive application of two-stage supercharging? I guess it's quite possibly been done and I just haven't heard of it, but I can't recall an instance.
Maybe from working in a 3rd axis. Altitude not usually an issue in maintaining boost in cars?
I vaguely remember a BMW two stage TURBOcharger setup at the auto show several years back. They were in series and different sizes. I don't remember much else (like if it was gas or diesel, etc). '07 or '08, maybe?
Clem
Twin charging (super and turbo) 4AG's has been around a while. I think either Greddy or HK$ had a system.
VW and Nissan have both have production cars with superchargers and turbochargers.
For years now I've seen references to turbo-superchargers on aircraft. I figured it was someone not knowing what they were talking about. I do know that some had two speed superchargers.
Lancia twin charged rally cars.
Ive seen Scion TCs get the TRD supercharger and then also get aftermarket turbo'd
spitfirebill wrote: For years now I've seen references to turbo-superchargers on aircraft. I figured it was someone not knowing what they were talking about. I do know that some had two speed superchargers.
Some WWII aircraft were "turbosupercharged" which was the 1940s way of saying "turbocharged".
Some used superchargers, some turbo(super)chargers and some a combination of both.
obligatory hotlink - and you thought a remote-mount turbo was a new thing?
Compound turbos are not unheard of in the diesel world but I have only heard of a handful on gas motors. It might be the best way to get huge pressure and flow but how many gas fueled engines can handle it for more than a few seconds?
Guy who used to work for me a had a dual turbo (not twin) 4G63, he put it in a first gen DSM. I've. Not heard how it fared though since he moved to Vermont. I'm hearing of more and more of them.
OTOH, VW needs to bring that twin charged Polo to the US.
spitfirebill wrote: For years now I've seen references to turbo-superchargers on aircraft. I figured it was someone not knowing what they were talking about. I do know that some had two speed superchargers.
Turbo or even turbocharger is essentially just shorthand that's now more or less universal. A supercharger is something which compresses the air going into the motor. A turbo is simply a turbine driven supercharger. Thus a turbosupercharger. It's only more modern usage where the term supercharger has (generally) come to mean something more specific.
http://rwebs.net/avhistory/opsman/geturbo/geturbo.htm
typically in aviation, the purpose of supercharging or turbo charging and aircraft isn't to add power to engine, as is the case with an automotive engine. Aircraft engines use superchargers or turbos to "normalize" an engine at high altitude.
When ever you see a horsepower rating of an aircraft engine, that rating is given at sea-level. As altitude increases and the air thins, the horse power will decrease accordingly, and at that point the added volume of air from a turbo or supercharger is used to basically fool the engine into thinking it's still at sea-level in the thick air.
The two speed supercharger is used in high speed at high altitude, and low speed at lower altitude, to avoid over stressing the engine.
There is also another use that turbos have seen on aircraft engines, typically called a "turbo compound" engine. The most popular was on the Wright R-3350 as used in the Lockheed Constilation triple tailed airliner. Each engine had 3 turbos, but the turbos were not used to turn a compressor or feed air into the engine in any way. They were used as power recovery turbos. Their output shafts transfered their power directly to the crankshaft using a fluid coupler. They recovered about 500 horsepower from the exhaust, for a total engine output of about 2700 hp.
I don't think the VW twin charged engine will run on 91 octane fuel, thats why we dont have it here.
The 4AGE twincharge system was HKS.
Twinscrew superchargers are a much better idea, they have the advantages of twin-charging (boost at low and high RPM) without the complications, there really isn't a good reason to twin-charge a car engine anymore.
Looks like it's about covered.
My dad used to tell me that there isn't really anything new in hotrodding. It's all been done before in aviation. The only difference is the application and the technology over time.
I was taught by dad (an aircraft mechanic) and in aviation mechanics school that turbo supercharger is the proper name for an exhaust driven supercharger or what is known as a turbocharger.
Fuel injection also derived from aviation, mainly to maintain steady fuel delivery while flying at all angles, like acrobatic/dogfighting.
jeffmx5 wrote:spitfirebill wrote: For years now I've seen references to turbo-superchargers on aircraft. I figured it was someone not knowing what they were talking about. I do know that some had two speed superchargers.Some WWII aircraft were "turbosupercharged" which was the 1940s way of saying "turbocharged". Some used superchargers, some turbo(super)chargers and some a combination of both. obligatory hotlink - and you thought a remote-mount turbo was a new thing?
Thanks for this. It's the best picture I've ever seen of this system and makes the whole thing perfectly clear.
I remember my G-Pa telling me that as he'd climb in alt., he'd feel the supercharger kick in. He said, you'd feel the plane start to slow down, then, it would kick in and it would start to accelerate like as if nothing changed.
My original question was focused on "two-stage" supercharging, which I believe is compressing the air flow once and then doing so AGAIN before being fed into the cylinders for combustion. I think Oldtin is correct and it's a function required by altitude, but I remember reading of somebody trying to do something like this at the Indy 500 and they kept blowing the head gasket. They were going to use an AMC inline 6 because it was the only thing that had head bolts large enough to tolerate the pressure.
My interest was sparked by the RR Merlin 61 (IIRC) which had two-stage two-speed mechanical supercharging. I knew the P-47 had a turbocharger but was recently surprised to find out that the F6-F and the Corsair both had two-stage mechanical superchargers despite using the same engine as the P-47. I was unaware they were supercharged at all.
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