With all the talk of turbos lately...

[Toast]

http://www.motorcycledaily.com/16april06_direct.htm

Direct injection turbos.

If it's good enough for BMW, I, like this dude, would say that it's good enough for production bikes.

That would spice things up a bit from the usual yearly rounds of refined and updated 600cc supersport and 1000cc superbike shoot-outs.

[bugjuice]

so what's the different (aside from higher compression) between conventional and direct turbo's then? I don't understand what the 'change' is..?

[Ixion]

It's the injection that is different. Conventional FI squirts the fuel into the intake tract where it mixes with the air being sucked through the intakes. then the fuel/air mix is drawn into the cylinder , through the intake valve and compressed, in the same way as a carburetted engine.

Direct injection works like a diesel. Only air is drawn through the inlet valve, and compressed. Slightly before TDC the fuel is injected directly into the cylinder. Petrol direct injection still uses a spark to fire the mixture though, whereas diesel relies on the very hot compressed air to set the fuel burning.

Because the engine is only compressing air, not air/petrol mix, which can prematurely explode (detonate) whilst being compressed, the engine can use much higher compression ratios (though maybe not as high as diesel ?) . The higher compression ratios suit turbocharging.

I think I got all that right, but it may be I'm talking bollocks, in which case I'm sure someone like Mr Motu will set me right.

[Bangbug]

Ixion you pretty much have it right :)
No, i don't think you can use compression as high as diesels.
But you're right about the detonation etc and the direct injection.
All good news really.
Good fuel econ, less lagg.

Due to the popularity of the triumph rocket etc it looks like a new horsepower war may be on! 200bhp bikes on the way..... New Kawasaki beats 200hp i think. Some of the older bikers ain't so keen on the corners anymore but still want some power to weight thrills. Nice lazy riding with a big punch in your right fist. Who wants to work the gears right? lol. :P

Not sure if i'd want to straddle myself over rocket with a turbine feeding it........ well....... maybe later :P

So bring back the years of the turbo 600's and 750's..... hehehe. I heard someone in japan turbo'd an Cbr250....... gave him 2 stroke power.......hmmmm :P
Toodles my lemon poodles

[Bangbug]

oh yeah, thats why conventional turbos have low comp..... the forced induction pumps it up. and yes, detonation. (detonation == hot air and fuel! :))
Toodles again, clean up your own poopies

[.produKt]

Hmm the phrase 'Direct Injection Turbos' makes me think that the fuel is sucked in with the air from the charge side of the turbo? if that makes any sence..

Just gimme 1600$ and ill mount a turb on my zxr :)

[Toast]

So bring back the years of the turbo 600's and 750's..... hehehe. I heard someone in japan turbo'd an Cbr250....... gave him 2 stroke power.......hmmmm :P
Toodles my lemon poodles

I heard that it gave him 250GP 2-stroke power...just shy of 100 at the rear wheel I think.

A turbo 600 or 750 is what I'm thinking would be some good stuff.

[Motu]

I hope BMW make a better attempt at direct injection than Mitsubishi did with their GDI engines.They were only game enough to to put them into their own domestic market though.....oops,and then they end up here.They apparently run EGR almost continuously to keep combustion temps down....that detonation mentioned earlier.This then fills the engine with so much crap the only way to clean pistons valves and combustion chambers is by using oven cleaner.The Japanese domestic market is used by the manufacturers for preproduction testing - why the fuck do we end up with the failed experiments?....sorry,rant mode off.

Direct injection is the ideal....pretty soon the petrol engine might be half as efficient as the diesel.

[Ixion]

But we are interested in bikes. And if the big advantage of DI is that it permits higher compression ratios, and higher power at (presumably) lower revs; will we not have the same problem as diesels in bikes. That the engine compenents, castings, scantlings etc have to be so strong and heavy that they are impractical on a bike. (I'm assuming that the turbo lag can be eliminated - not a good thing on a bike , that, I would think).

Dunno, m'self, just wondering.

[Toast]

. (I'm assuming that the turbo lag can be eliminated - not a good thing on a bike , that, I would think).

Dunno, m'self, just wondering.

That seems to be pretty much the whole point in the article. BMW is now using the turbo tech that they have shunned for ages (apart from the old 2002) due to its average throttle response because they reckon that the direct injection helps to get over this.

I think Audi and a couple of others have a range of direct injection petrols on the market now, so I'm guessing that it can be done better than the Mitsi GDIs.

[Crasherfromwayback]

But we are interested in bikes. And if the big advantage of DI is that it permits higher compression ratios, and higher power at (presumably) lower revs; will we not have the same problem as diesels in bikes. That the engine compenents, castings, scantlings etc have to be so strong and heavy that they are impractical on a bike. (I'm assuming that the turbo lag can be eliminated - not a good thing on a bike , that, I would think).

Dunno, m'self, just wondering.

A really interesting item on www.motorcycledaily.com that refers to BMW's fiddling with such engines from memory.
I think it should happen NOW.

[Toast]

A really interesting item on www.motorcycledaily.com that refers to BMW's fiddling with such engines from memory.
I think it should happen NOW.

I think you mean the article referenced at the top that started the whole thread...?

[Motu]

Turbos run on waste heat,not gas velocity,heat is energy,and it converts that energy back into work.The direct injection gives higher compression ratios without detonation,which gives higher combustion temps,which give higher exhaust gas temps,which spool up the turbo quicker and give more waste heat to convert into work.

[Crasherfromwayback]

I think you mean the article referenced at the top that started the whole thread...?
The exact same one.
Pass me another Steinie!

[Toast]

The exact same one.
Pass me another Steinie!

Steinie? That's like, early '90's at best dude...Stella is the beer of choice here in Shit City...actually I think it's Heineken now...things move so fast.

[onearmedbandit]

I hope BMW make a better attempt at direct injection than Mitsubishi did with their GDI engines.They were only game enough to to put them into their own domestic market though.....oops,and then they end up here.They apparently run EGR almost continuously to keep combustion temps down....that detonation mentioned earlier.This then fills the engine with so much crap the only way to clean pistons valves and combustion chambers is by using oven cleaner.The Japanese domestic market is used by the manufacturers for preproduction testing - why the fuck do we end up with the failed experiments?....sorry,rant mode off.

Direct injection is the ideal....pretty soon the petrol engine might be half as efficient as the diesel.

Umm, Motu GDi's were sold throughout the world. They were first released in 1996 in Japan, have since been sold new in different parts of the world.

What other 'failed experiments' do we end up with that are not used in other markets?

[bugjuice]

so in lesser words, this whole thing is just a direct injection engine (which has been around for yonks) with a turbo strapped on?
There's nothing special or different about the turbo, it's actually all about the motor it's bolted on?

And there was an internet article about some dude who injected his CBR250RR, then bolted a turbo onto it..
you can turbo almost any motor in theory

[Ixion]

Hm. Been sniffing around. 'Twould appear that the detonation problem is not QUITE solved! Or at any rate, there seems to be a lot of interest still in solving it!

Reading between the lines, it would appear that GDI works OK, so long as everything is *exactly* spot on. But in the real world (bugger of a place, that), things seldom stay "spot on" for long. Then Mr Detonation comes a calling. And given the beast that GDI is, that may mean a completely wrecked engine in a few seconds (Though no engine manufacturer will admit to that!). To counter that, instances so far either use a markedly over rich mixture, or full time EGR. Which is fine and dandy on a new engine. But once the miles clock up, oh dear.

And turbocharging is going to make all of those worse. Much worse.

BTW, GDI was first used by Mercedes in 1955 on the 300SL. It was then "reinvented " by Mitsubishi in 1996. So it has staggered out of the pits a few times, and each time died ignominiously. The reason that manufacturers are pushing it back onto the track is Californian fuel efficiency requirements. As noted, on a nice new engine, under ideal conditions, GDI can run ultra lean, and produce very nice consumptions figures. Quite good enough to make the Californian grade. And the californian legislators do not actually consider what happens a year or two down the line. Phew, we're in boys.

I don't think I'll hold my breath., And if it did actually get up and running I'd have to ask - if we've gone that far down the road toward what is almost a diesel engine, why not go the whole hog and go diesel?

[Motu]

Umm, Motu GDi's were sold throughout the world. They were first released in 1996 in Japan, have since been sold new in different parts of the world.

What other 'failed experiments' do we end up with that are not used in other markets?

For a start you answered your own question - first released in Japan.

Secondly,they are failed experiments because they were never intended to run beyond 7 years,or whenever they were put off the road in Japan....we are continuing to run the experiment to it's conclusion.I think everyone has concluded that the Mitsi GDI is a total fuck up.

[Crasherfromwayback]

Steinie? That's like, early '90's at best dude...Stella is the beer of choice here in Shit City...actually I think it's Heineken now...things move so fast.

As you can see mate...not for me!

[onearmedbandit]

For a start you answered your own question - first released in Japan.

Secondly,they are failed experiments because they were never intended to run beyond 7 years,or whenever they were put off the road in Japan....we are continuing to run the experiment to it's conclusion.I think everyone has concluded that the Mitsi GDI is a total fuck up.

First released in Japan, yes. But you made no mention of new sales elsewhere (including New Zealand). And you alluded to used imports. But anyway, I agree. GDi is a total fuck up.

[slimjim]

But we are interested in bikes. And if the big advantage of DI is that it permits higher compression ratios, and higher power at (presumably) lower revs; will we not have the same problem as diesels in bikes. That the engine compenents, castings, scantlings etc have to be so strong and heavy that they are impractical on a bike. (I'm assuming that the turbo lag can be eliminated - not a good thing on a bike , that, I would think).

Dunno, m'self, just wondering.:gob: should have a read up on the diesels bike that's been built oversea's, lovely':doobey: