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BMW 3-Series (E90 E92) Forum
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OMG... e90 "electric supercharger" on ebay..
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04-14-2006, 10:42 PM | #1 |
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OMG... e90 "electric supercharger" on ebay..
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04-16-2006, 07:56 AM | #2 |
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You know some suckers are buying them. That's a ton of dough for a cheap fractional HP fan.
Producing cfm is one thing. Producing cfm at a reasonable psi level is another. There's a reason that most supercharger compressors run off the crankshaft lol. Without getting my pencil out, I would think any motor required to produce decent psi and airflow would be in the 15-20HP range...and that ain't running off your alternator/battery without some upgrade.
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04-16-2006, 08:04 AM | #3 |
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"it makes a nice sound making it seem like you got something bigger then what you actual have under the hood" "A stock turbo from an Audi 1.8T produces 400CFM" no mention of psi
I'm sorry I s#!+ myself laughing... |
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04-16-2006, 10:13 AM | #5 |
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From their FAQ...
"How much CFM will the supercharger produce? The supercharger produces 250 CFM but when combined with a cold air intake it produces about 2 PSI of boost. " Is there any chance that this would produce the 15-25hp gain they suggest? It seems a modest claim for a 'supercharger', so could it actually work? OK I admit it, i'm a sucker... |
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04-16-2006, 10:34 AM | #6 |
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The concept is valid. Legitimate electric superchargers can and have been made, they require THOUSANDS of watts to power.
Just like most any product, there are good executions and there are poor executions. This is a VERY poor one. |
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04-16-2006, 10:52 AM | #8 |
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seriously...if it were that easy, don't you think car manufacturers would do it. 2.2 amps is not enough to make the kind of air you need to feed an engine.
Eve try to inflate a tire with a 12v compressor? yes they advertise 225 psi but the cfm they can produce is so low. it takes forever to inflate your tire. Then there's the camping inflator...producing lots of CFM but low pressure, again working off 12V. You'd need an enormous electric motor, with much more current draw and a very high tech impeller (appropriate bearings) to produce enough CFM and a reasonable boost pressure to make a difference...would be to costly and ineficient or else car manufacturers would have mess with this, as they have all other "tuner" mods. |
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04-16-2006, 10:53 AM | #9 | |
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Quote:
...and lose horribly |
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04-16-2006, 11:39 AM | #11 |
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www.electricsupercharger.com nuf said.
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04-16-2006, 03:59 PM | #12 |
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POSTED FROM A GOOGLE CACHED PAGE:
How To Waste Money -------------------------------------------------------------------------------- E-RAM Electric Supercharger Updated 10 February 2001: I recently got an email from the head honcho of E-Racing, maker of the E-Ram. Read his letter, and my response, here. Updated 08 February 2004: I finally performed some dyno runs using the E-Ram. You can see the pitiful results here. While the ads touting this product make a very seductive argument for buying and installing this item, the actual performance gain is so small as to be unnoticed. The E-Ram only powers up at WOT (which is when you'd want it to power up). It is supposed to give up to 1 PSIG of boost; unfortunately, it does not deliver. Before I can rip apart the ridiculous claims made by this product's vendor, I have to explain what is supposed to happen. Consider a 2.5L V-6 with a volumetric efficiency of 82%, and with peak HP at 5850 RPM. We need to find the amount of air, in cubic feet per minute (cfm), that this engine is able to pass at peak HP. Now, the displacement of the 2.5L engine (is 2.5L, but we're going to work with cfm) is 152.4 cubic inches. Using the above mentioned facts, we can figure out how much air the engine is capable of passing. vfr = (rpm * 0.5 * cid * ve) / 1728 Where: vfr is the volumetric flow rate of the engine rpm is the engine RPM where expected maximum power is developed cid is the cubic inch displacement of the engine 0.5 is a factor that takes into account that an gasoline engine only moves air for two of its four cycles 1728 is the conversion factor from cubic inches to cubic feet Now, we plug in numbers. vfr = (5850 * 0.5 * 152.4 * 0.82) / 1728 = 211.5 cfm From the above formula, we find that the 2.5L V-6 is able to pass a maximum of 212 cfm at WOT. Now, the E-Ram is supposed to provide a 1 psid boost at WOT, which would be 212 cfm for the V-6. To provide this much boost for this flow rate of air, one must expend about 1 HP, or about 746 watts (W). Taking this into consideration, and assuming for the moment that the E-Ram is able to provide this boost without any mechanical or electrical losses whatsoever, the E-Ram should draw (746 W)/(13 V) = 57.4 A (amps) when it is running. However, under test, this item only draws 15.3 A, for a power draw of 199 W (0.27 HP). So, at most, the E-Ram can provide about 1/4 psig of boost, which is hardly enough to offset the HP loss just by running this thing. To compound the situation, the E-Ram actually provides a intake restriction when it's turned off (during any part-throttle response). This, in turn, requires the engine to work harder just to draw air in, which is power that could have been used instead to propel the car forward. |
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04-17-2006, 11:04 PM | #13 |
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i bought one it is soooo popular that it is on back order.... :rocks:
syk....i would never buy this piece of sh*t...hahahhahaha..i saw em too on ebay and laugh for like 10miz
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nuff said! |
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04-18-2006, 12:29 PM | #14 |
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what tl posted makes it seem logical but if any one has looked at the vids on their site it seems like it may work.....
but then again im not buying that pos |
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