Rookie Posted April 9, 2015 Share Posted April 9, 2015 I don't know how to convince you that turning the super charger off is a bad idea, so I won't try, but read that evo thread and look at the results. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted April 9, 2015 Share Posted April 9, 2015 As far as the mode of operation, there are a couple of way of doing it: Turbo first, or blower first. Lancia opted for the former, positioning the supercharger closest to the engine for immediate response, and incorporating a valve to allow the turbo to bypass the blower when up to speed and pressurize the intake charge with less restriction. http://www.spannerhead.com/2012/11/21/technical-curiosities-twincharging/ http://www.infinitegarage.com/twin-charged-engines/ Quote Link to comment Share on other sites More sharing options...
Rookie Posted April 9, 2015 Share Posted April 9, 2015 That person obviously doesn't know what they are talking about, you would never blow through the turbo with supercharger. They are wrong about the s4 too. Quote Link to comment Share on other sites More sharing options...
Rookie Posted April 9, 2015 Share Posted April 9, 2015 Also there is no possible way a positive displacement supercharger can cause a restriction. Man, where do you get this rubbish? Quote Link to comment Share on other sites More sharing options...
Yowzer Posted April 9, 2015 Share Posted April 9, 2015 VW totally blew through the turbo with the supercharger. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted April 9, 2015 Share Posted April 9, 2015 Yes the restriction part is incorrect. Also I'm yet to find anything that states the Delta ran full time compound. Also, google. A wealth of semi-information. Quote Link to comment Share on other sites More sharing options...
Rookie Posted April 9, 2015 Share Posted April 9, 2015 Like I said watch a video of one. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted April 9, 2015 Share Posted April 9, 2015 http://www.autozine.org/Archive/Lancia/classic/Delta_S4.html Another problem of the outgoing 037 was lack of power. Even in ultimate form its supercharged engine mustered only 325 horsepower. The S4 produced 470hp from the outset. Its engine was downsized to 1759cc (to slip into the 900kg class), but it was boosted by the most advanced forced induction system of the time – a mechanical supercharger plus a turbocharger ! It was the world's first of its kind. Contemporary turbochargers were not as efficient as today's. They provided no boost at low rpm and a great deal of turbo lag, which affected drivability. For a rally car, a flat torque curve over a wide range of rpm is always crucial, since it has to accelerate out of corner from very low speed to near top speed in 10 seconds. A mechanical supercharger could complement the black hole at the low-end power delivery and resulted in a flat torque curve. Nevertheless, a supercharger is always power consuming, the worse the higher the rev. Therefore Lancia designed the system such that once the turbo got running, a bypass valve relieved the pressure from the supercharger so that the latter was deactivated. The theory seemed simple, but it took Lancia and Abarth a lot of research to smoothen the transition between supercharger and turbocharger. Quote Link to comment Share on other sites More sharing options...
puddles Posted April 9, 2015 Share Posted April 9, 2015 the vw 1.4 tsi twin charge uses a clutched eaton supercharger that blows through a small turbo up to about 3000rpm and then is clutched out and runs on turbo only. above 3000 rpm a valve opens and the supercharger is bypassed. its a really cool engine to drive and is rapid enoungh. we had problems many with owners filling them with 91 octane and putting holes in the pistons. you can find that motor in everything from the golf to the tiguan and new beetle. vw stopped using that motor because i think its too costly. you can get the supercharger to kick in in reverse gear which is pretty funny Quote Link to comment Share on other sites More sharing options...
Yowzer Posted April 9, 2015 Share Posted April 9, 2015 This Quote Link to comment Share on other sites More sharing options...
Rookie Posted April 9, 2015 Share Posted April 9, 2015 Untill you find me someone from lancia who says they switched off the supercharger I won't believe it. There is no reason to run two intercoolers if you aren't compounding boost. These people have all been tricked because of this image which shows air going arond the supercharger, all that is is the idle stabilzation. Read the Evo thread he talks about idle IATs going through the roof because he blanked his one off. Watch this video and tell me when you can't hear blower whine all the time. Quote Link to comment Share on other sites More sharing options...
Rookie Posted April 9, 2015 Share Posted April 9, 2015 This I was talking about compund setups when I said you wouldn't do it this way. sorry for the miss understanding. And while great for fuel economy, it is not so great for out right area under the curve, which is what makes twin charging dominate. Quote Link to comment Share on other sites More sharing options...
Rookie Posted April 9, 2015 Share Posted April 9, 2015 Actually this video does an even better job of proving my point that they never turn the supercharger off. And thinking about it, this is the only bit of proof you should actually need. There is no reason to run two intercoolers if you aren't compounding boost. Quote Link to comment Share on other sites More sharing options...
Hemi Posted April 9, 2015 Share Posted April 9, 2015 I read the blurb on Scanias turbo compound unit and it has a geardriven unit that works off've the crank additional to the turbo. Would you guys like to read it? I have access to the service info on my laptop. I thought it was a turbine in behind the turbo that went through a gearbox and attached to the flywheel? pretty sure thats how the Volvo ones work anyhow . I might also be thinking of something completely different Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted April 9, 2015 Share Posted April 9, 2015 I thought it was a turbine in behind the turbo that went through a gearbox and attached to the flywheel? pretty sure thats how the Volvo ones work anyhow . I might also be thinking of something completely different Yeah I just read it again, feeds power directly into the gearbox: TurbocompoundingTurbocompounding relies on utilising a larger proportion of the heat energy in the exhaust gases by means of a power turbine 1. The power turbine is located in the exhaust pipe downstream from turbocharger 2 and the exhaust brake. The power turbine is of the same type as the one in the turbocharger. The exhaust gases from the engine propel the turbocharger turbine at high speed while the compressor side of the turbocharger supplies air to the combustion process. The exhaust gases pass the exhaust brake and continue to the power turbine in the turbocompound unit, which rotates at a speed of approximately 50,000 rpm. The power is transmitted via the gear 3 to a hydraulic coupling 4, which evens out speed variations between the turbocompound unit output shaft and the crankshaft. Via another set of gears consisting of a hydraulic coupling gear, an intermediate gear and a crankshaft gear, the power is then transmitted to the engine flywheel 5 and on to the gearbox . In comparison to a conventional engine, turbocompounding offers a number of advantages. The output and the torque is higher and the fuel consumption is lower in comparison to an identical engine without a turbocompound unit. Quote Link to comment Share on other sites More sharing options...
Alfashark Posted April 9, 2015 Share Posted April 9, 2015 ^ The old Power Recovery Turbine idea... As used in the Wright 3350 Turbo Compound radials from late 1945/early '46. http://en.wikipedia.org/wiki/Wright_R-3350_Duplex-Cyclone#Design_and_development Quote Link to comment Share on other sites More sharing options...
Testament Posted April 9, 2015 Share Posted April 9, 2015 Untill you find me someone from lancia who says they switched off the supercharger I won't believe it. There is no reason to run two intercoolers if you aren't compounding boost. These people have all been tricked because of this image which shows air going arond the supercharger, all that is is the idle stabilzation. Read the Evo thread he talks about idle IATs going through the roof because he blanked his one off. dave is right on this lancia never declutched the supercharger or had anything to do that (and go wrong) henry toivonnen wasnt gonna lift so why declutch it? +1 my car does not have an idle bypass and the idle and esp decel IAT's go nuts, like from 70-80 degrees under load (no intercooler) to 120 degrees when you engine brake from high rpm. Quote Link to comment Share on other sites More sharing options...
Hemi Posted April 9, 2015 Share Posted April 9, 2015 ^ The old Power Recovery Turbine idea... As used in the Wright 3350 Turbo Compound radials from late 1945/early '46. http://en.wikipedia.org/wiki/Wright_R-3350_Duplex-Cyclone#Design_and_development Yeah , they are awesome till the gearbox/ shaft on the turbine siezes and rips itself off the side of the block . Quote Link to comment Share on other sites More sharing options...
Ghostchips Posted April 9, 2015 Share Posted April 9, 2015 (Not specific to thread lingpost style question) Why have wastegates instead of an intake pressure release valve that makes hilarious noises? This question arose at 2 am Quote Link to comment Share on other sites More sharing options...
AllTorque Posted April 9, 2015 Share Posted April 9, 2015 Because the turbo is a restriction in the exhaust. A wastegate bypasses some gas around the turbo. Some super charged setups use an intake pressure release, like a blow off valve. 1 Quote Link to comment Share on other sites More sharing options...
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