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locost supercharger
02GF74 - 23/10/06 at 09:22 AM

Maybe a stupid question but since I have never examined a turbo then you have to excuse me.

How difficult would it be to take a turbo unit, replace the exhaust drive vane thingy with a pulley and drive it off the engine like a supercharger?

(I'm guessing not since someone else would have thought of this but with the plethora of turbos out there, surely there must be one that can be converted?????)


liam.mccaffrey - 23/10/06 at 09:25 AM

problem is you would be driving a pulley at many many thousandes of revs. I think however it is possible, the g60 supercharged vw corrado had a setup like this, I think it had reliability issues though, could be wrong.

as a retrofit i doubt it would be feasable though, but happy to be proved wrong


Bluemoon - 23/10/06 at 09:25 AM

I guess the problem is getting High enough RPM, from a belt drive...


Coose - 23/10/06 at 09:29 AM

I had a Polo G40 in my youth and it was ace! The G-Lader is a form of supercharger, more like a rotary engine rather than a twin-vane charger as per the standard units.

It ran at 1.6 times engine speed as standard, though mine ran a bit quicker as it had a smaller driven pulley.

Your best option is to look at the new Mini supercharger as they're plentiful due to being changed if the car is fitted with the John Cooper upgrade. I've never used one, but it'd be a good place to start!


JohnN - 23/10/06 at 09:51 AM

I believe that a turbo would normally spin at several hundred thousand rpm, hence needing precision gearing if driven by a belt......
See this thread here

[Edited on 23/10/06 by JohnN]


02GF74 - 23/10/06 at 09:55 AM

ok; a pulley to drive a couple of gears?


JAG - 23/10/06 at 10:12 AM

This is very do-able if a bit specialist.

.... and as you may guess has been done lots before. A supercharger can use any type of impellor/compressor and there have been many made with centrifugal compressors as found in turbochargers.

There was also the BRM Type 15 V16 F1 car that ran a large centrifugal supercharger in the 1950's.

Also do a search on here as I remember seeing a thread recently where someone was planning on fitting a commercially available centrifugal supercharger.

HERE IT IS.

[Edited on 23/10/06 by JAG]


NS Dev - 23/10/06 at 10:13 AM

bit more complex than that, an epicyclic box would be the best bet.


liam.mccaffrey - 23/10/06 at 10:21 AM

i agree epicyclic gbox could be best


Agriv8 - 23/10/06 at 10:37 AM

From reading the Article in PPC last month about turbo rebuild. surly getting the thing balanced would be a concern.

Just my 2p worth

regards

Agriv8


02GF74 - 23/10/06 at 11:33 AM

... this is more of a thought experiment about using a turbo.


Surely the balancing could be overcome?

if blancing is an issue, what about fitting a turbo from a larger engine, say 5 l (lorry engine?) to a car engine, 1.6 l - so it moves a bigger volume of air - will that provide the same pressure but at lower rpm than a car turbo?

(something tells me it is not as easy as that).


NS Dev - 23/10/06 at 11:38 AM

have a look at what Turbo Technics offer, and also at the innards of a Rotrex, all use either geared or friction epicylics plus a big turbine casing and wheel from a truck etc.


JAG - 23/10/06 at 12:21 PM

Centrifugal compressors drop out of the maximum efficiency zone if you run them too slow and heat up the intake air even more, just like an ordinary supercharger.

The major advantage of a centrifugal compressor is efficiency - they're around 70% efficient compared to less than 50% for a Roots type of supercharger.


clutch_kick - 23/10/06 at 12:54 PM

just my 2p of thought ...

... anybody thought about using an electric ducted fan unit to supercharge an engine? The latest RC motors are very powerful, with brushless operation.

Just a few advantages I can thinik of:
*Lightweight
*Speedcontroller is Mappable
*Electric .. i.e. no power drain from the Engine.

I'm sure this set-up will provide a good 5-8psi of boost, The airflow of the system has to be calculated, and then match up the throughput of the Ducted-Fan unit to the engine size, i.e. bigger displacement = bigger fan.

We were going to supercharge a Fiat 126 600cc engine with a 5 in fan unit, just enough to provide 4 psi boost. Might sound very little but you roughly get 2-5 bhp per psi, depending on how good your installation and mapping/jetting/ignition is.


JackNco - 23/10/06 at 01:10 PM

its been done. there is a company called procharger in the USA that do them. ive got a leaflet on my desk here lol.

The prices they are charging are silly.

Basically its a turbo thats powered by the pulley system. they actually do one designed for a focus so would be find on a 2L Zetec.

Its a T6 Turbo geared up/down 5.40:1 or there abouts depending on the model. ive toyed with the idea a few tims but never done anything about it




[Edited on 23/10/06 by JackNco]


JackNco - 23/10/06 at 01:13 PM

BTW there is also another company that do one for a focus and they reckon u can get 8PSI out of it without an inter cooler. with the uprated puller for higher spin speeds


jono_misfit - 23/10/06 at 01:17 PM

theres a UK company does them for Bikes.

TTS i think.

We used one on the Firehawk. 1400 Busa engine with Supercharger.

Belt driven, with epicyclic box on the back.

Works well


JackNco - 23/10/06 at 01:25 PM

lol bet there not cheap, wounder if u could strap one on a zetec n get any results


02GF74 - 23/10/06 at 01:32 PM

quote:
Originally posted by clutch_kick
just my 2p of thought ...

... anybody thought about using an electric ducted fan unit to supercharge an engine? The latest RC motors are very powerful, with brushless operation.




please do a seach; I posted about the cheap electric superchatger that are bineg sold on ebay - in short, the fans producr volume but not much pressure.

and will draw a fair amount of current so do load the engine via the alternator - where did youy think the power to drive them was coming from?


ReMan - 23/10/06 at 02:54 PM

quote:
Originally posted by 02GF74

and will draw a fair amount of current so do load the engine via the alternator - where did youy think the power to drive them was coming from?


But thats always the case, i'm sure i've read that belt drive superchargers can use anything up to 100Hp to drive them


zetec7 - 23/10/06 at 04:25 PM

As far as the speeds are concerned, exhaust-driven turbochargers frequently run up over 100,000 RPM - that's a lot of gearing to get out of even a BEC...