"PlayerWAN" (PlayerWAN)
01/11/2014 at 01:19 • Filed to: None
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"PlayerWAN" (PlayerWAN)
01/11/2014 at 01:19 • Filed to: None | 0
| 10 |
Hey fellow oppoites, here with a (probably noobish to some) question. I can't quite grasp how a carbureted engine works with a roots blower. I understand how each of the components (the carb and the blower) work independently, but I'm not totally sure how they work together. Is fuel sent all the way through the blower? That seems awfully inefficient... Anyone care to chime in with a cool explanation? Slightly NSFW pic for the trouble.
DrJohannVegas
> PlayerWAN
01/11/2014 at 01:20 |
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Yep, fuel goes through the blower.
Grindintosecond
> PlayerWAN
01/11/2014 at 01:26 |
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a "draw through" system. the earliest turbo cars had a carb on the front side of as turbo too...corvair monza for instance.
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PlayerWAN
> Grindintosecond
01/11/2014 at 01:47 |
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I see. That's crazy, it seems awfully inefficient, but then again, I'm no engineer.
roflcopter
> PlayerWAN
01/11/2014 at 02:08 |
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Compressing/heating fuel is never a good thing. That's why boost prepping carbs and doing a blow through setup is way better than a draw through setup. It's definitely cheaper to do a draw through but the risk is way higher and you can't be nearly as aggressive with tuning one as you can a blow through.
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PlayerWAN
> roflcopter
01/11/2014 at 02:25 |
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How is it cheaper? (serious question)
Saracen
> PlayerWAN
01/11/2014 at 03:49 |
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You're right, it's not efficient. Carburetors are horribly inefficient anyway. It's one of the reasons why my mom's Plymouth Duster did 9mpg.
Dirty Harry Callahan
> PlayerWAN
01/11/2014 at 04:02 |
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Because you don't have to build a pressurized box which the carb would sit in. It's bad because now the blower is getting coated in fuel and it doesn't help the cold start performance at all. Atomized fuel now condensing inside the blower itself sure doesn't make for an easy startup. A blow through carb setup requires more tuning and the carbs are now hard to access but the fuel doesn't touch the blower helping improve the lifespan of the blower lobe seals. With today's tech though, why they carb a boosted vehicle is only for looks because in the end a fuel injection setup will be far and away more reliable, efficient and powerful.
Oh and that Goat with sequential blowers is just retarded, if they set it up properly you'd only need one, seriously Top Fuel dragsters only need one.
rotundapig
> PlayerWAN
01/11/2014 at 07:02 |
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The one advantage of pulling fuel thought the blower is that the fuel can cool and even lubricate the lobes of the blower. On some engines (blown alcohol pro-mod, for instance) this is mandatory, although they tend to use mechanical injection.
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Grindintosecond
> PlayerWAN
01/11/2014 at 08:57 |
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its inefficient but dirt simple to do in the end. the other way would be a "blow through" where the carb would have to be in as sealed box pumped with supercharger or turbo boost or what is done now...fuel injected after the boost without all that carb stuff but its much more complex.
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roflcopter
> PlayerWAN
01/11/2014 at 11:39 |
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It's cheaper because you don't have to worry about the carb seeing any boost. It's essentially just a matter of slapping a carb on the inlet of the blower instead of somewhere preferably after an inter cooler where the carb has to be jetted/tuned for seeing anywhere from -12psi-15+psi depending on boost and vacuum of the engine.
Go look up how much a fully boost prepped carb is compared to a 'normal' version of the same one.