[Mk2] [Turbo] can u get a turbo from a diesel to work on an mr2

[simmo490]

thinking about buying one of these cheap rev 2 tubby engine knocking about,

i also have one or two of these lying about



whats the chances of doing a load of fabrication and getting it to work on the engine??

[wierdo]

could be tricky.lot of diesels use varying vane technology which is used to help stop lag but means that it wouldnt have a flap for a wastegate as it would have a charge pressure control unit instead.although they look like a wastegate they do very different things.they are also operated by vaccum not pressure like a petrol car's turbo.if it is just a dirty great turbo you would also encounter problems like having to seriously crank up your fuelling to match the immense amount of forced air it could shove back into your engine.either that or watch your pistons turn into melted lumps due to extreme lean mixture.things like the angles and pitch of the fins on the compressor wheel and impellor wheel also have a big role to play.

[alexwainwright]

Wierdo is partly right - not sure sure what you mean by "operated by vacuum not pressure".

Only the very latest diesel turbo's, and even then only a small minority, are variable geometry. The one in the pics is not VG - just a standard type turbo (although it is actually twin entry, much like the standard MR2 turbos!)

There is a bit of a problem with diesel turbos - they usually have comparatively large turbine housings (as is very obvious on that one!), so wouldn't spool up very easily. It's hard to say how well it would work without looking at a compressor map. It could run into surge quite easily.... or you may just not be operating anywhere near the decent efficiency areas of the map. It would be a PITA to do all the work only to find it drives like a bag of s**t.

Also, the materials are designed for lower temperatures - but then again they are also designed for much higher duty cycles, so would probably be ok. Diesel exhaust gas temps are around the 700 deg max mark, whereas you're looking at around 900 deg C for a petrol engine.

Alex

[RyanRs]

No point mate.. its the sizes of the casings / compressor and exhaust turbines that determine the charaistics of a turbo. the principle of one is simple, but the actuall science behind them is a lot more 'complex'.

that turbo looks like its poss off a 7.5tonne lorry, doesnt look big enough to be a 18T class2 etc.. but still, you think, a 7.5 tonne will have an engine size of around 7-8 litres , and more than likely 6 cylinder or more, and running maximum power / torque at about 1500 RPM, redline at about 4,000 RPM.

a little 4-pot petrol wouldnt have the puff to get that thing going to its efficiant operating level, and if somehow it did, you would be pulling in enough air to supply boost to a potential 7L 6+ cyl engine.. dread to think what would happen next!

[wierdo]

I was refering to the charge pressure control units on vg turbo's being operated by vaccum generally and wastegates usually being opened by pressure onto the actuator.As you say though this does look somewhat commercial so pretty much rules it out

[PW@Woodsport]

you cannot run a diesel turbo on a petrol car at all! they are made from different materials internally and will not cope with the temps on a petrol engine,net result being you will get turbo failure or bits of turbo entering the engine and killing it.

Putting a diesel turbo on a petrol car is a seriously bad idea.

[simmo490]

um your right it aint off a 18t truck, its off a 25t truck with a rolls royce lump in it

anyway that clears it up