Why would you supercharge when you can turbocharge??
Turbo Mini Forums

Why would you supercharge when you can turbocharge?? .. Been looking at Members' ace photos and see that quite a few of you guys run superchargers ...WHY?

Only the turbocharger gives you owt fer nowt ..by using waste
exhaust energy .. while a supercharger uses some engine power

OK, with a super you get no lag and loads of low down torque ...
... is that it?

its all about lag. some hate it and some of us love it (dont like too much though)

turbos give you that punch in the back

Edited by ppj_racing on 16th May, 2007.

the man that built my engine used to work for Lancia and preped the 037's etc. he also worked on Will Gollops turbo 6R4 metro

surely it must be fairly easy to measure what losses a turbo gives?

Run it on the dyno but with nothing connected to the plenum. i.e. boosting but not supplying the engine with boost.

then do the same but with a lcb.

would be interesting.. hmm maybe a uni dissertation...

I've heard the free power argument before and though durrr?. No such thing as owt for nowt (perpetual motion ring any bells?)

I think you test needs a bit more thinking about Iain, loading the turbo for instabce, but yes would be interesting.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Run 2 engines with one running NA but with a turbo boosting the other engine.

you could still produce the boost though wil... just not use it.

i would say run 2 engines but as well all know 2 engines dont run the same power...

got this idea in my head now... best talk to uni!!

I just thought dyno an NA engine on an engine dyno then put on the turbo and the other engine will just take the boost and load the turbo, it doesn't matter what spec/power it is, it's there to take boost.

ah as in use the boost on an engine at the side...

i dont think that you'd need to if you replicated the hose as the orrifice size of the plenum...

defo an iteresting idea, whether or not it would work as a final yr uni project i dont know.

the reason i want to do something like this is i have particularly poor motivation when it comes to assignments. if i'm actually interested it would mean i could do it.

good thing is uni would do all the machining i need, most likely for the new engine too. could do it with the K1100 head then...

Yes, I don't think that you need two engines. I was just thinking of a dummy load i.e. a restrictor. If the compressor has nothing to restrict its output then you won't create a realistic backpressure.

I simulate miles of railway using a resistor network in the lab, I'm just thinking along similar lines.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

But won't you need a throttle butterfly, carb, manifold etc (even the whole engine) to get the true restriction? I don't think you'd load the turbo with just the plenum.

Edited by Jay#2 on 16th May, 2007.

Not really, you could derive a dummy load that would be close enough to give good results.

As I said this is what I do sometime with dummy loads for electric circuits. It's never going to be 100% but close enough to give good results.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

end if the day you want it balls to the wall, so the butterfly etc will be wide open.

i'm sure it can easily be done to load it with a suitable orifice.

certainly a lot of things to consider but interesting. going to have a chat with some lecturers tomorrow i think!

Im surprised nobody has considered using a centrifugal supercharger on a Mini yet....

A small Rotrex unit would probably work extremely well.

You wont get that huge rush of torque low down, but you will get massive gains up top.

Think traction and drivability.

Turbos are superb, but when trying to achieve big numbers, which is easy...it often comes with a downside, especially on small engines, which is that massive step between on, and off boost creating a huge difference in power/torque.

And the torque breaking things.

Edited by stevieturbo on 16th May, 2007.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Just do what I think Axel was doing... use both! Turbo feeding a super. I might be tempted by a similar set up, depending on the finances when I get to building the engine.

There is no sense crying over every mistake- you just keep on trying til you run out of cake.

do you realy need both? when you can gget 200bhp woth turbos??

i dont know weather you would benifit anything by having more than 200+bhp in a front wheel drive mini! not sensibly anyway! lol

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Hi,
Stevie .. I wouldn't be surprised if the huge off on transition attributes to the breakages...
Cheers,
Gavin :)

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On 16th of May, 2007 at 06:14pm stevieturbo said:
Im surprised nobody has considered using a centrifugal supercharger on a Mini yet....

A small Rotrex unit would probably work extremely well.

You wont get that huge rush of torque low down, but you will get massive gains up top.

Think traction and drivability.

Turbos are superb, but when trying to achieve big numbers, which is easy...it often comes with a downside, especially on small engines, which is that massive step between on, and off boost creating a huge difference in power/torque.

And the torque breaking things.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

The turbine needs energy to drive the compressor. That energy is in the form of pressure, temperature and velocity.

The only way it can get that energy from the exhaust gas is to rob it from the combustion process. Hence at the end of the combustion stroke the conditions in a turbo engine cylinder are different from a NA engine.

This has an effect of the output of the engine. You dont get owt for nowt as TD says.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I have a supercharger. Why? Here is Aus, it's much cheaper, it's easy, they look nice when all polished up, a hell of a lot less piping, tons less heat, can be switched off for any reason (I never do though) and give me the torque I need. (I live in a very hilly, country area).

PS, I use an SC12, a Toyota supercharger.

Supercharged 1964 Morris 850 - Now 1330cc with 7psi.

Every day is a school day ...........

How fast and how expensive ...... the same question...