Supercharger project

Hey guys,

most of you will know im an engineer, and I have a wee project you may be interested in.

I am currently developing a boundary-layer turbine that will be used to pump water, but can compress air too, and in a unit the size of a 10 pack of cdr's can make 40psi easily at 3k rpm. I am still working on the prototype at work but I was thinking it would make a ****** good supercharger, as it takes minimal force to run it (im developing it to pump out a lagoon of 1,000,000 gallons of water that usually takes a 100kw pump (73bhp) to do, with only 4kw of power driving my turbine design.

If it turns out to be viable, I would have it manufactured as an add-on blower, and beleive it or not, a 1" (25mm) scale model was able to produce 20psi with a power input of 0.18kw (0.13 bhp) so it would seem to be the ideal machine for increasing an engines output without sucking engine power to run it. It has no real internal resistance to flow, and needs no dump valve, as it isnt a reaction or impulse turbine like conventional turbochargers. It doesnt stall when the outlet is blocked!

Obviously airflow in cfm is important in car turbine design, and pressure is not the only factor, but it will be designed to accomodate the airflow requirements of the engine and still produce the correct pressure, early trials have shown the turbine can reach rotational speeds of 120,000 rpm with no damage, and so 6k from an engine is a walk in the park and may not even need a pressurised oil supply.

(as a sideline project, im making a gas-turbine jet engine from an old frontera 2.2 tdi Garret T15 turbocharger, using diesel as fuel, a fire extinguisher as a combustion chamber, an injector from an audi TDI 130, and a glowplug from the same.....watch this space!)

anyway - my supercharger will have almost no lag, instant boost, mbc control (ball & spring valve) for max pressure setting (5psi is safe for NA cars) and its only 150mm (6") across by 40mm (1.6") thick. Driven by an auxiliary belt, it could be fitted to any car by just changing the shape of the outlet hose end.

Just thought id gauge the interest from a good band of car enthusiasts like your selves.....

Comments welcome!

I hope to keep the cost down below £200 depending on the manufacturing charges and whether I can get a consistent quality from the people who laser-cut the turbine discs.

Anyhoo, will keep you all posted as said and hopefully a working one can be trialled on a car and the results published.....just have to pick up a donor hack and if it looks good results-wise, try to get a manufacturing deal struck with an engineering firm to produce them.

docurley said:

Well if your looking to apply this to a NA car then the 3.0 may be the one but for a big interest and to make good money I would say the S4/RS4 V8 is the market to look at.

Intercooling or charge cooling the system would I think be a must then you may want to talk to a mapping company to help with the ECU side of things.

I think N/A Audi engines are good for around 9-9.5 psi before going bang.

A cheap supercharger kit right now would be a very good niche right now.

Click to expand...

Yeah thats what I was thinking since the existing kits are extortionate prices. Combined with a simple air-to-air cooler it would probably still be cheap, and much more effective, cheers for the suggestion there doc.

I do intend that the charger could be fitted to any NA engine since the physical space it takes up will be minimal and the outlet volute scroll can be piped to any intake throat by just changing the boost pipe end, so that any car can use it mounted on a simple bracket since the turbine is essentially flat, and looks like a pack of cd's sorta shape. It doesnt use a conventional bladed turbine wheel so has little or no resistance to spin at low rpms but as the speed builds then so does the pressure, very quickly but also very smoothly.

Conventional "reaction" and "impulse" turbines take a lot of force to spin them through the air even slowly since they have a large amount of drag, hence I started down this road to produce an alternative low-energy self-priming pump for mixed fluids (mostly water with suspended solids) but it pumps thick sludge equally well, and since it can also pump gases, it makes a great compressor, thats what got me thinking about alternative use as a supercharger.

Im having the turbine discs made at a local engineering firm who do a lot of work for my employer so that will take a lot of the burden off me when building better prototypes and refining the device. Im using sealed-for-life ball-bearings that we install on machinery that lives in harsh environments and is difficult to maintain, since I hope to need no lubrication to the bearings which simplifies the applications it can be used for. Plus if the charger lasted say, 30k miles but only needed bearing replacement it still looks good value i think.

Cheers for the support guys, and i'll put up some pics of the prototype and maybe a video on youtube of it running over the next few weeks.

lol, cheers for all the input and comments guys! and no_idea, thats a cool offer mate, thanks. I'll get in touch when I get a chance.

Was thinking, it doesnt need a cooler as theres no "hot wheel" - its belt driven.

To answer somewhat about why it should be good cheap and reliable, the construction is much simpler than a conventional turbine wheel, theres only one moving part, no heat, and a 1.5" prototype makes 20psi at 10,000 rpm.

So in car terms, we only need say 5 to 10 psi max, but with enough airflow to accomodate the engine requirements. Since 5psi is easily within its abilities, a larger one will flow plenty of air and due to the design it has little or no resistance at idle or overrun so no dump valve needed, just a mbc ball & spring valve to limit max pressure to the required amount.

Unlike a normal turbine it free-wheels for ages after power is taken away, and it doesnt stall when the output is blocked, therefor no dv required, and should have instant spool up.

Since its not complicated to manufacture, it should be possible to keep it cheap, and since it could be used on a lot of cars, more sellable and again that keeps the price down. The casing will be cast or machined duralumin and the internals tempered stainless steel. One boost pipe, one bracket, one pulley and a toothed belt is all the kit will consist of!


I think supercharger & turbo manufacturers have high prices because sales are limited so they need higher prices to profit, and manufacturing costs are high on complicated machines.