8 second quarter mile on biodiesel

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MA
Wow thats pretty cool. 80psi. No intercooler they just use water injection. i wonder where they place the nozzle(s), before the turbos or after?
 
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18
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east tennessee, usa
quote:
Originally posted by Santo Fontana: Wow thats pretty cool. 80psi. No intercooler they just use water injection. i wonder where they place the nozzle(s), before the turbos or after?
Bound to be after, before would erode the blades in the turbo. [Edit: also, you get more cooling action the bigger the difference in water temp and the air it's injected into.] Hey, my first post was a useful one, do I get a prize? -asi
 

Shannow

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'Stralia
Asimov, particularly with race type engines (low mileage, driven on weekends) water is injected prior to the turbo. Improves atomisation, and can use boost pressure to regulate water delivery. WRT to erosion, I've seen water take 30lb 33.5" turbine blades clean off the rotor.
 
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east tennessee, usa
Ok, I guess on a race motor it makes a little bit of sense. I based my statement on the pictures I have seen of turbos after sucking up rainwater due to poorly located cold air intakes. I believe I would spring for some more/better injectors to improve atomization rather than spray it through the turbo even if it was a racecar. Besides, what about the heat transfer? It's always more effiecent the wider the tempature gap, and, up to the point that it vaporizes, the water is still fine for phase change heat transfer in the cylinder. Or have I misunderstood something? I've never actually used water injection, though I did consider it for a while in my 2.3L ford turbo.
 

Shannow

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Asimov, I've read that passing through the impeller (obviously) breaks up droplets, and more finely disperses them. They evaporate during the compression process, and still cool. Think about putting 1kg of air, and 7 grammes of waterin a vessel and rapidly compressing it, versus compressing the air, then adding water. The end results should be pretty much the same.
 
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18
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east tennessee, usa
If you add water after you compress (and heat) it, it will be more efficent, because the wider the heat differential, the more efficient the heat exchange. For that matter, adding water to the air and then compressing it wouldn't cool the intake charge much, if any. Now that I think about it the only chance that would have to cool anything would be in the cylinder when it undergoes a phase change. It wouldn't cool the compressed air at all, it's being compressed (and heated) at the same time as the air. So I guess cooling the intake charge isn't that big of a deal to the ones doing it (obviously the turbo health doesn't matter)
 
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There are some real high output diesel marine engines for go fast boats .The higher the output the shorter the life. More boost and feul= more power.
 
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