Flight

Proper old school documentary on how your turbo engine works

http://www.youtube.com/watch?v=xbB1qwhKaaE

J4CKO

iTrader: (1)

Thanks, very interesting !

mgcvk

Wooden molds in 1984 I say! Favourite quote "several hundred formula one engines do not warrant an investment in computer aided design"

craigo

iTrader: (1)

brilliant, is there a follow on to that episode ?

craigo

iTrader: (1)

ah, got it... http://www.youtube.com/watch?v=gqfVA...feature=relmfu

AndyC_772

iTrader: (2)

Excellent stuff - just finished the first part and about to settle down with a mug of tea to watch the second.

What surprised me wasn't so much how engines and manufacturing have changed since then, but how documentaries have changed. I can't remember the last time I saw footage of real engineers actually carrying out proper development work... no dumbing down and no condescending presenter telling us how important it is that this stuff has spin-offs which help the world be a greener place.

Leslie

Some years ago when Renault were the first to turbocharge an F1 engine, they were successful so I thought I would have a go at doing the same to my racer just for the hell of it.

It was a 1300cc BDA engine and I was getting about 125 BHP at 11500 rpm.

I bought a s/h turbo off a trucking companyand borrowed the book on turbos from the library. I went into all the theory and how you had to install the correct compressor for the mass air flow and constructed the pipery to fit it all to the engine. I was using Lucas mechanically metered fuel injection so I had to use a disused runway to tune the fuelling by doing ignition dead cuts and spark plug readings. I altered the fuelling by filing the cam which was moved by the throttle and measuring it on the spot with a clock gauge.

It sounds ridiculous but it all worked perfectly by the end of the afternoon and I was getting 265 BHP boosting at 15 psi.

It was a very driveable car and was very nice to go booming down the straights with the very expensive cars on the track.

One of the most interesting bits of design and construction that I did in those days.

Les

hodgy0_2

thats pretty cool Les

I used to send my wife to sleep by explaining the theory of turbos to her

and still 25 years later if she is having trouble getting to sleep she will ask me to explain again

one dfay I will send her on a proper course

Jimbob

iTrader: (13)

Awesome programs, just half way through the last one>
I can remember Equinox on TV, just goes to show how dumbed down things on TV are now, with their pleasant to look at (invariably thick) tv presenter, and sweeping angles of camera.

Leslie

Get her to have a go at a practical application!

Les

tony de wonderful

They were used in WW2 piston engined aircraft. It's not like F1 invented turbos.

Leslie

Did anyone say that turbochargers were invented purely for use in F1?

I did say that Renault was the first firm to use a turbocharger in F1. Did you misunderstand what I said?

One advantage of a turbocharger is that the impellor is driven by a turbine which in turn is driven by the energy from the exhaust gases of the engine in question. This system therefore uses the energy from the exhaust which would otherwise be wasted. The more work the engine is asked to do, the more energy is available to drive the turbocharger's turbine which will produce more boost should it be needed. A supercharger which is mechanically driven will require extra power from the engine to drive it and which is therefore wasted power.

Les

AndyC_772

iTrader: (2)

Is that really true Les? Surely the engine does mechanical work to push the hot exhaust gases out of the cylinder, and the turbocharger acts as a restriction in the exhaust which therefore increases the amount of work the engine has to do?

I guess if the exhaust is still at greater than atmospheric pressure by the end of the power stroke, it will expand when the exhaust valve opens, which in turn would allow some work to be done 'for free'.

jef

iTrader: (13)

cosworth "the search for power" makes some good reading, altho just about mike costin and keith duckworths company, a fair bit about their turbo charged engines

im sure it was a1.5l v6 making 1200hp lol

all those years ago - think it ran baout 5 bar IIRC lol

New_scooby_04

iTrader: (4)

Yep ........... for one lap.....then it s'ploded!

jef

iTrader: (13)

1 laps good enough haha

wouldnt have expected it lasted as long lol

even still for all those years ago - impressive

although they were as anti turbo as it came then it seems

J4CKO

iTrader: (1)

I just suggest a **** to my wife and she is out like a light

Leslie

Yes but that work is being done with either a supercharger fitted or with a turbocharger. Fitting the turbocharger gets rid of the mechanical work required to drive the supercharger which is extra to the basic mechanicaL requirements of the engine.

The exhaust gases have heat energy as well as that due to the gases' inertia as they travel along the exhaust system. The act of driving the turbocharger's turbine will extract both of that kind of that energy from the gases and transfer it to the impellor in order to add speed and pressure to the inlet column. Fitting a turbo then does enable some of the energy in the exhaust gases to be used in order to increase the engine's output power instead of being thrown overboard as in a normally aspirated engine.

The turbocharger can run at speeds up to as much as 180K rpm which is pretty staggering. Mine was running at around 130K. It was necessary to construct a wastegate to dump exhaust gases in order to control the max boost supplied to the engine. I was using 20PSI max but the turbo was capable of supplying over double that, for as long as the engine would last with that much boost anyway, ie not very long!

There is actually not as much back pressure as you might expect in the exhaust system with a turbocharger in line. The gases flow through the turbine very easily. There is so much extra boost available that it would not reduce the power available in fact.

The turbine extracts heat energy as well as pressure and speed energy from the exhaust gases. It is amazing how slowly the exhaust gases leave the turbo and how much cooler the gases are too on exit. The turbo acts as a fairly good silencer, or to an extent anyway.

Les

Evolution Stu

iTrader: (2)

This isnt strictly true, A turbocharger will always increase an engines pumping losses, the only time it starts to get even close to a well designed nasp exhaust is at full boost and even then, it is still significantly more restrictive than an exhaust without a turbocharger inline.

scooby red

iTrader: (2)

Bookmarked for bedtime

Leslie

I agree that if the exhaust system is not designed to take full advantage of the exhaust flow that there will be losses as described.

My own exhaust system was designed to be as efficient as possible when the gas flow was taken into consideration. I found no significant power loss throughout the engine operating range with the turbocharger in line and of course a very large increase in power once the turbocharger began to supply measurable boost to the inlet manifold. I certainly did not see any sign of power loss due to restrictive exhaust flow. My engine was producing close to double the unboosted BHP with less than 2 bar boost so the exhaust system could not have been that inefficient. Once the engine had positive boost available it was powerful throughout the boosted RPM range.

Les

Evolution Stu

iTrader: (2)

The fact remains, restriction is actually a requirement to make the turbocharger work.
Most people wouldnt argue that a huge amount of energy is lost to heat on any turbocharger installation I am sure?
Well that heat is caused by the very restriction that you are suggesting doesnt really exist.

Its very easy to measure mate, just measure the EP on a standard exhaust, then measure the TIP on your turbochargers exhaust primaries and the results are clear as day. A turbocharger cannot operate with no TIP and lowering it to improve the engines VE then moves the engines powerband upwards along with turbocharger responce, however, you need to lower TIP as soon as you start to produce a TIP / MAP ratio of anywere past 3:1 anyway, ideally a little sooner, so you cant have your cake and eat it with a standard turbocharger installation, that is why variable geometry was designed, as it actively controls TIP.

The Pink Ninja

iTrader: (23)

Ross Brawn really suits those glasses, Lol,

Evolution Stu

iTrader: (2)

Must actually watch these videos... not found time yet.

Leslie

I really can't be bothered to argue about it all. I can only go by my own practical experience in which it all worked.

Les

Evolution Stu

iTrader: (2)

Its not an argument mate, far from it, I thought we were having a technical discussion.



Me too, on literally thousands of engines.