Just to thicken the plot, KKK developed a combined unit that used the exhaust gas waves and a an engine driven impeller to get the best of both a supercharger and a turbocharger. It works well on industrial diesels http://www.stopstart.fsnet.co.uk/smilie/eek4.gif , but when Ferrari tried it on their F1 Turbos in the 80's it couldn't take the rate of increase in revs of a racing engine and proved unreliable.

Markus

Got to go with Adam on this one. Nitros assisted Turbo is the way to go. No extra compressors or plumbing with no drag on the engine.

You'd probably only need a 25 HP system with a throttle switch to come in early and close at 2500 revs or so. It would make the car seem like it had another litre capacity! The turbo would spin up much quicker and the residual charge temps will be cooler meaning more boost when the turbo is on line. The Nitros bottle should last quite a while as it is only squirting for a short time when you need it (you would have a seperate arming switch- just like Mad Max with his supercharger red button on his gearstick).

David Vizard did a guide on it.OK!

F

Just an idle question I thought of yesterday really. Feel free to ignore... http://bbs.scoobynet.co.uk/wink.gif

Why do most manufactures decide to put a turbo charger into a car to give it more power rather than a supercharger? I assume it's because a turbo involves less re-design of the engine and can be fitted onto their stock units. Are turbos easier to produce/fit? Are they more reliable than a supercharger? I understand that supercharges are more common in the US. Has anyone driven a supercharged car? What are the differences in power delivery to a turbo?

Why do they not use Supercharges in rallying? Would it not reduce the lag (or does the ALS get over this anyway?).

Amazing what goes through your head when your gardening... http://bbs.scoobynet.co.uk/wink.gif

OK for what it's worth....

Technically speaking a turbo charger is a form of supercharger - it simply uses exhaust gases rather than the mechanical method that a traditional supercharger uses. I suspect the main reason is weight. A turbo charger is the easiest/lightest way to improve bhp/tonne figures.

I'm sure there is more to it, but that's a start http://bbs.scoobynet.co.uk/smile.gif

Chris

Nimbus, while wathering the plants, I found this : http://bbs.scoobynet.co.uk/smile.gif

A supercharger produces a more linear gain than a turbocharger. That's all I know. http://bbs.scoobynet.co.uk/biggrin.gif

A turbo charger uses exhaust gasses to drive a turbine thats linked to a compresser that pressurises the intake system. A turbo system has lag as it has to wait for the exhaust gasses to build up enough pressure to drive the turbo compressor fast enough for it to produce boost.

A supercharge also uses a compressor but this is driven off a crank pully and so the compressor had no inherent lag. The boost is there throughout the rev range hence the linear progression.

Turbos are capable of producing higher boost levels than superchargers.

Turbos also generate more heat than a supercharger and so incur air charge temperature problems and hence the use of intercoolers and chargecoolers. The higher the level of boost the higher the operating temperature of the turbo and hence the need for greater ATC cooling systems.

Bren

Also supercharging is powered by the engine itshelf so at high revs it sucks a considerable amount of engine power for compression purposes. The turbo uses "free" energy of exhaust gases. As for rallying us old men remember the Lancia S4 having both volumex scharging at low revs and t/charging higher up. Ahh those were the days...

As Stelios brings up the subject of turbo and super chargers on the same engine... (think you know where this is going http://bbs.scoobynet.co.uk/wink.gif)

...what advantages/disadvantages would there be from adding a supercharger to a scooby turbo?

My idea would revolve around the supercharger for low to medium revs, then over to big 'ol turbo for that high end kick.

Ignoring the mechaincs of it all, I guess the major problem would be getting the system working so that the supercharger cuts out at a certain rpm, with the turbo taking over. My guess would be that the turbo would always be available, but as it would be a big un it would suffer from low rpm lag, which would thus be compensated by the supercharger, then when over X rpm the turbo would be up to speed and take over.

sound feasible? or am i nut nut (yeah, I know I am http://bbs.scoobynet.co.uk/wink.gif)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by EvilBevel:
<B>Nimbus, while wathering the plants...
[/quote]

Weeding actually http://bbs.scoobynet.co.uk/wink.gif Good site though..


Thanks guys.

Markus, it would be much easier to produce an anti lag system, or use nitrous to boost power before a whopping turbo charger comes in.

Plumming for what you are talking about would be a nightmare, plus incase you didnt notice, there isnt that much room under the bonnet for another compressor.

getting one to take over from the other wouldn't be too difficult though, a simple actuator controlled valve, related to boost could do that, in the same way as the wastegate, with an electromechanical clutch on the supercharger pulley to disconnect it wheh the turbo takes over.

Superchargers drink fuel all the time... turbo chargers drink fuel when you use them... i.e. all the time... http://bbs.scoobynet.co.uk/wink.gif

Superchargers do give a more natural linear power delivery... so they would be well suited for rear wheel drive applications where progressive throttle control is a big plus.

So is that why Mercedes have gone for a Supercharger in their "Kompressor"? Is it because it's more drive-able without the lag of a turbo?

I've driven the SLK 230 Kompressor and it's actually great fun on snow/ice. Much easier than dealing with the turbolag. It feels more strong than quick.

I prefer quick... http://bbs.scoobynet.co.uk/biggrin.gif