1. #11
    So a supercharger is the same as a compressor?

    Thought every engine would need that in thin air, why not a ww2 piston engine?
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  2. #12
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by tjaika1910:
    So a supercharger is the same as a compressor?

    Thought every engine would need that in thin air, why not a ww2 piston engine? </div></BLOCKQUOTE>

    Yep, the supercharger and compressor is the same thing. Perhaps it`s the German fondness of marking it as 'Kompressor' on cars what makes the confusion. In their ww2 aero engines, they refer to it as 'Lader', but it`s the same thing.

    And yes, 99.9% of the ww2 piston aero engines were supercharged, because of the reason you pointed out, they needed it at altitude, + because of the performance boost (all engines were supercharged with 30-250% higher manifold pressurethan ambient air pressure). The confusion probalbly comes from there were worser and better superchargers... but powerful s/c were also traded low altitude performance for better performance at altitude : they took engine power away when it was not neccesary, though some designs such as Junkers and Daimler Benz employed solved this with hydraulic couplings to the s/c and variable inlets.

    More on turbos, from what I heard, they can be annoying in everyday use, you have to run the engine on idle for a minute or two before stopping the car, to allow the turbo blades to gradually cool down. Otherwise they can crack... and that`s expensive. Could be a pain in the ***.
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  3. #13
    bird_brain's Avatar Senior Member
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    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kurfurst__:
    And yes, 99.9% of the ww2 piston aero engines were supercharged, </div></BLOCKQUOTE>
    Unfortunately the P39 @ the beginning of WWII was not. This limited their high altitude performance and meant it could not go above about 15000 feet. The engine lost too much power. When it was designed, the Army did not think they would need it.

    You could look here as well;
    http://www.aviation-history.com/engines/allison.htm

    It supplies a great explanation of gear driven vs. turbosupercharger systems on Allison engines in the P40 and P38.
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  4. #14
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by bird_brain:
    Unfortunately the P39 @ the beginning of WWII was not. This limited their high altitude performance and meant it could not go above about 15000 feet. The engine lost too much power. When it was designed, the Army did not think they would need it. </div></BLOCKQUOTE>

    The Allisons were supercharged - think about it, if they were not, the engine would immidiately loose power above SL, with the air density dropping - however the superchargers performance was enough only to provide supercharging and constant pressure up to 15 000 feet. That`s not bad btw, rahter typical for early war fighters. Ie. the 109E`s, Spit I`s etc. supercharger could only provide constant pressure up to about 16 000 feet, too. Above that their engine output declined as well.

    As I said, the diffo is between how powerful the installed supercharger is, not that it`s supercharged or not. Powerful superchargers are heavier, and take more power away at lower levels, so at low levels you loose power. Ie. the Spit IXF had good performance at 28 000 feet, but it was so-so at lower levels, compared to earlier Spit Vs with less powerful superchargers. The Army seems to thought it`s up to 15 000 feet where fights could happen, so they optimized the plane/engine for that. It`s always a compromise between wheter you require good high alt or low/medium alt performance - unless you employ a hydraulic clutch like DB 60x engines did. Or you can go with a turbocharger, but that`s not well suited for fighters, being large, bulky and expensive and requireing more maintaince.
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  5. #15
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by FI-Aflak:


    yeah, diesels basically have to be turboed or they hardly produce enough power to drag their own weight around, let along a truck.

    Fun thing about a diesel is, especially with that cummins turbodeisel you can get in Dodge trucks is this: you can up the mixture and the compression to crazy levels and the thing keeps giving you more and more power. sure, its dumping unburned gas out the tailpipe, but the power it gives is incredible. I've got a vid of an F-350 with a Cummins turbodeisel in it (Dodge engine in a Ford truck, I know . .) . . the thing is lifted, has big knobby offroad tires. Not a car you would expect to be overly fast, right? Well its at a drag strip, facing a Supra. lights go green supra jumps ahead, then the F-350 takes off, leaving a black cloud out of the tailpipe and runs a 10.5 or something. That truck does a faster quarter mile than almost all the hypercars you can buy. I think the Enzo runs the 1/4 is 11.something. Of course, the Enzo is going to have a higher top speed and there will be no handling comparison, but for brutal acceleration the giant american diesel truck wins. The race being over, just set your mixture back to normal and drive home, truck as normal as could be. </div></BLOCKQUOTE>

    You must obviously not paid attention to the development to diesel engines last decade. Diesels have a lot more momentum, some cars have incredible torque of 700 Nm combined with lots of horsepowers. A typical car with a diesel is more economic, clean and powerful than a benzin car with the same volume.


    Thanks Kurfurst. I wondered what supercharcher was, thought it was something old, like a pre electronic injection or whatever used mainly in american cars.

    A low presure turbo, with intercooler does not behave like some posters have implied turbos do. To bad turbo is not fashion at the moment. But I guess diesel is the new thing here. Even BMW had to do something.
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  6. #16
    Taylortony,

    I thought I recognized a 58P (or TC) Baron. My straight 58 is a whole lot easier (not to mention cheaper) to work on but, alas doesn't go as fast or as high as the turbos do. I just installed a new port engine as well but mine only cost $35,000 US.

    Hint: use a shorter CH4108 oil filter instead of the long CH4109. It filters just as well and gives more clearance.
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  7. #17
    stathem's Avatar Senior Member
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    The Lancia Delta S4 Grp B rally car used to use a 1.8L motor with a supercharger and a turbocharger, something like 500-600 Bhp. The super was used because big turbos in the '80's suffered from severe lag, and the mechanical blower provides more power and torque lower down the rev range. Modern day production turbos use much smaller and lighter impellers which spin up faster at a lower back pressure. The WRC cars of today have a water injection and anti-lag devices in order to reduce turbo lag.
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