Electronic Superchargers - 986 Forum - The Community for Porsche Boxster & Cayman Owners

denverpete · 02-19-2006, 07:25 PM

I've noticed several threads regarding the "electronic superchargers" that seem so prevalent on E-Bay. Obviously the general opinion is "junk" and I have to agree. But, there's nothing wrong with the principle (which is why I think these things keep popping up). So, being bored, I decided to investigate a bit. Here's some info I found.

This site has a pretty comprehensive explanation of what they are, how they work, and why they don't do what they say. Instead of plagarizing this guy's work - I'll just list the link http://www.dansdata.com/danletters105.htm The article is the 4th headline down. What's interesting is that most of these are apparently bilge ventilating fans for boats!

I did look up the data on Thomas Knight's ESC Electric Supercharger and was pretty impressed. This is a real supercharger driven off of battery power (requires 1- 3 extra batteries). I found an interesting article in Turbo Magazine about the product. http://www.turbomagazine.com/tech/0406tur_knight/. You can also check out their website at http://www.boosthead.com/home.php From what I can see, this is apparently one of the few, if only, legitimate electric superchargers out there. But as such, it also cost nearly $1700.

I don't know how well it would work with a Boxster but the bonus seems to be that it's about as close to a Mad Max switchable supercharger as any of us will get! Anyway, check out the links, there's some interesting information there.

Adam · 02-19-2006, 07:29 PM

Please do it and tell us how it goes ok....

MNBoxster · 02-19-2006, 07:40 PM

Hi,

Generally these are very limited. If driven off the Alternator, there's a limit to the amount the Alternator can produce and there is a Parasitic loss as it uses Crank HP (The Jaguar XK8 Supercharger draws away 70 Crank HP at Peak Boost). For an independently powered one, of course the drawback is the extra weight of the Batteries, seriously negating the benefits.

But add to this the inherent Mechanical inefficiencies and the low amount of boost they're capable of ,and it's not a really worthwhile Mod...

Happy Motoring!... Jim'99

denverpete · 02-19-2006, 08:50 PM

Quote:

Originally Posted by MNBoxster

Hi,

Generally these are very limited. If driven off the Alternator, there's a limit to the amount the Alternator can produce and there is a Parasitic loss as it uses Crank HP (The Jaguar XK8 Supercharger draws away 70 Crank HP at Peak Boost). For an independently powered one, of course the drawback is the extra weight of the Batteries, seriously negating the benefits.

But add to this the inherent Mechanical inefficiencies and the low amount of boost they're capable of ,and it's not a really worthwhile Mod...

Happy Motoring!... Jim'99

I'm not advocating the system, I simply thought it was educational for those interested in these types of things. But, to play devil's advocate:

1. The ESC is not driven off of the alternator, hence no parasitic losses. The idea is to use it similar to a Nitrous shot - but one that is rechargeable.
2. I really don't think that 18 lbs of blower + 60 lbs of battery seriously negates the benefits.
3. The device is capable of up to 6 psi boost.
4. The device installed on a 2.5L 4 cylinder Ford Ranger dyno'd an increase of around 38HP and 50 ft-lbs. Installed on a V6 Dodge Avenger it showed around 75 HP and 114 ft-lbs.

No - I'm not putting this on my Boxster - but I think it's an interesting mod and might be worthwhile for some.

MNBoxster · 02-19-2006, 10:47 PM

Pete,

I'm always skeptical whenever an AfterMarket Company throws Dyno Testing into the Mix. I mean there's Dyno Testing and then there's Dyno Testing.

One Company's product was tested on a Dyno, and they did get the Readout they wanted for Advertising purposes - they did however leave out the fact that the Engine needed a total rebuild once they were done - but the Truth in Abvertising Guidelines were met.

There are so many variables on a Dyno that a repeatable, verifyable result is frequently unachievable. If they don't publish the Methodology, it's all bunk!

People put Great Faith (read Too Much Faith) in someone else's Dyno results. I just read an article about the Guy from Wisc. who invented the Rolling Dyno. He Tried to market it to AfterMarket manufacturers. At $25k/copy, it was a tough sell. One Major Manufacturer flat out told him, why would I spend $25k, when I can market junk by placing a $5k Ad in a Car Mag and get $50k worth of Sales from it..??

But, the Dyno gain popularity and the Faith of the Average Joe. So today, Dyno Testing has become De Rigeur for anybody with a Fancy, New, Widget. But, there is a wide degree of accuracy in Dyno results, often greater than the increases boasted by the Manufacturer. If say the Super were Free-Wheeling, then that much boost may be attainable, but in real life, I doubt it.

It takes a lot of energy to produce 18PSI of Boost. The impellor needs to be very precise, not to mention the torque and power of the electric motor. These things have great inefficiencies - they do not transfer Energy well due to Mechanical Loss. It is fairly simple Mathermatics - there is only so much usable Work to be derived from 1 Horsepower. Take away Mechanical inefficiencies and a Unit has to draw waay more power than the actual work it's producing. The Blower is not an innovative technology - it is no more efficient than a Blower powered by another means. The Electric Drive Motor isn't innovative - no more powerful than any other, so I'm not convinced.

But, if I ever do find a way to make more from less, I'll have a Car Collection which puts Seinfeld, Leno, and Ralph Lauren to shame...

Happy Motoring!... Jim'99

denverpete · 02-20-2006, 06:01 AM

Jim,

All very good points. And I think it's good to be skeptical about horsepower gains - particularly with all of the claims we've seen out there. No one should expect "bolt on gains". It just doesn't happen. Believe me Jim, I completely understand the math and dynamics behind superchargers.

My question is: Did you read the information I provided through the links? To me it doesn't sound as if you did. That's fine if it's the case - I appreciate your insight and knowledge regardless. But if you did read the links, well then I'm really interested in your analysis of this product in specific and not electric superchargers in general.

BTW, I found a great article about some guys who built their own "bilge pump" blower and they found that it actually dropped their HP by 10! They removed the device with a baseball bat.

MNBoxster · 02-20-2006, 07:25 AM

Quote:

Originally Posted by denverpete

Jim,

All very good points. And I think it's good to be skeptical about horsepower gains - particularly with all of the claims we've seen out there. No one should expect "bolt on gains". It just doesn't happen. Believe me Jim, I completely understand the math and dynamics behind superchargers.

My question is: Did you read the information I provided through the links? To me it doesn't sound as if you did. That's fine if it's the case - I appreciate your insight and knowledge regardless. But if you did read the links, well then I'm really interested in your analysis of this product in specific and not electric superchargers in general.

BTW, I found a great article about some guys who built their own "bilge pump" blower and they found that it actually dropped their HP by 10! They removed the device with a baseball bat.

Hi,

I did read all the articles. I still believe the Drawbacks exceed the Benefit. For instance, it's only available for short bursts, great if you're coming out of the 4th Corner heading for the Line, but on the Street, not all that useful. Also, you invariably shorten a Naturally Aspirated design Engine by Forcing it, admittedly a compromise many are willing to take.

There are a number of pretty Wild claims so far as HP increases, longevity and reliability are concerned. No mention is made of required Mods to Injectors, Exhaust and ECU or the costs associated with them. I don't have one or use one, so I cannot state this unequivicably, but if it offered that much promise, the Guy would most likely be Marketing it to Major Manufacturers rather than the DIYer, because that's where the real money would lie.

Multiple Motors and isolating the power draw from the Car's own system are somewhat innovative, but not Earth Shattering. As I said, I am not as yet convinced. Also, I own a Turbo-Designed car - the Esprit. I inherently dislike Forced Induction primarily because of the Car's Split Personality. I think a lot of Super/Turbo appeal comes from the noticable kick when the Boost comes on, but I find it upsetting. I had enough of that when I was a Government Employee being shot off Carrier Decks back when I was too young and too stupid to know better...

Happy Motoring!... Jim'99

denverpete · 02-20-2006, 10:55 AM

Thanks Jim! See, that's the kind of insight I was looking for!

I agree that the "shot boost" has limited appeal to me - but maybe not to others.

I too am not the biggest fan of forced induction for the reasons you listed. I remember test driving a Volvo S60R not too long ago (all wheel drive, comfortable, a bit sporty). I have to admit I was pretty embarassed by my driving. I would hit the boost point and suddenly throw myself and the dealer back into our seats. All on or all off. I'm sure with experience I could have mitigated that effect, but it was a major turn off at the time.

Brucelee · 02-20-2006, 11:46 AM

If all one wants is a SHOT boost, I think Nitrous (spelling?)is the way to go! Cheap too!

denverpete · 02-20-2006, 03:13 PM

Quote:

Originally Posted by Brucelee

If all one wants is a SHOT boost, I think Nitrous (spelling?)is the way to go! Cheap too!

Mmmmm.... Nitrous.

MNBoxster · 02-20-2006, 07:15 PM

Quote:

Originally Posted by Brucelee

If all one wants is a SHOT boost, I think Nitrous (spelling?)is the way to go! Cheap too!

Hi,

I thought about a Nitrous Kit, but couldn't figure out how to plumb it into the Cabin... " I was really going 17MPH Officer? Seemed much Faster..."

Happy Motoring!... Jim'99

Adam · 02-20-2006, 07:20 PM

Quote:

Originally Posted by Brucelee

If all one wants is a SHOT boost, I think Nitrous (spelling?)is the way to go! Cheap too!

Your spelled it wrong Richard, it's Nawwwzzzz. Get it right

denverpete · 02-20-2006, 07:23 PM

Quote:

Originally Posted by MNBoxster

Hi,

I thought about a Nitrous Kit, but couldn't figure out how to plumb it into the Cabin... " I was really going 17MPH Officer? Seemed much Faster..."

Happy Motoring!... Jim'99

LOL! It's the PERFECT solution for all those who aren't happy with the power of their Boxster. It wouldn't add any power - but at least they'd be HAPPY!

Brucelee · 02-21-2006, 06:21 AM

We are not only the smartest Boxster forum on the web, we are the funniest!

:dance: