924Board.org

[timstar92404]

Just curious if these things actually work, not talking about the smaller ones but like this one I saw on Ebay.

Just want to know if they could work. Not that I have the ability to fit one on my car, just want to know if they work because I've never heard of this before.

the other small ones on ebay look like scams and I can't see how a small fan would do anything but this one says it provides up to 6psi of pressure.

http://cgi.ebay.com/ebaymotors/ELECTRIC-SUPERCHARGER-FOR-YOUR-CAR-6-PSI_W0QQcmdZViewItemQQcategoryZ107063QQitemZ4572016210QQrdZ1
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78 924 sold.
85.5 944

[CBass]

Judging from the size of that thing, I'd say it was more suitable for the guy's motorcycle in the first place!

While usually these "electric superchargers" are simply an inline fan, that is an actual lobe type compressor, so the compressor side would definately give some pressure. Whether the motors there can provide enough power and speed to get any meaningful boost out of that very small compressor, that's another story.

Remember that it takes a few horsepower just to drive even a small supercharger, because of the resistance of the air to being compressed. You'd probably need 4-6hp(rough guess) just to spin that little thing, which would have to be generated by the alternator before powering those little motors, and that takes a lot of curent, that the original alternator is just not big enough to supply.
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'81 931 in various states of assembly

[Physcho]

actually, If this unit is similar to one that Thomas Knight is selling at the moment (the ESC 350C electric supercharger) it uses a couple of 12 volt batteries to drive the supercharger in short bursts (<10 seconds), so it would be similar to running Nitrous Oxide. you only get a couple of go's before needing to recharge it, Which can be done either by connecting your battery bank to a battery charger, or putting in a 200 amp alternator and recharging while you drive.

the website is http://www.boosthead.com/home.php

it actually looks to be an earlier version of that supercharger, it's referenced on the E-Rams page http://www.electricsupercharger.com/buyersguide.shtml

"One costs over $2000, and uses a "roots" style blower driven by three 6HP electric starter motors (18HP of electrical energy). This system uses belts that connect the motors to the compressor to run it at a high enough rpm to develop boost. Although almost 20psi of boost can be generated below 50 cfm, as the engine accellerates to higher rpms and requires higher air-flow, the amount of boost generated by the system drops dramatically (to roughly 5 psi at 300cfm). The 18HP of energy required to do this must come from a separate battery supply that weighs roughly 70lbs, and the compressor itself also carries a weight penalty of 25+ lbs. Since the power draw is coming directly from a separately charged battery supply, the entire system can only be used for a couple of drag runs before a waiting period must occur for the engines charging system to recharge the separate battery supply for future use. Add this to the need for a modified engine management system and fuel delivery system, and the costs, weight, and limited useability make a case for going with a traditional belt driven supercharger or exhaust driven turbocharger system"

it's certainly a novel idea.

oh by the way, i'm new, hi (never was one for formal introductions)
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People who think they know everything really annoy those of us who do.

[ESC944]

Well it is certainly one of the early versions, "Geoff" aka Thomas "Goeff" Knight, made them. That version is based on the Eaton M62 Mercedes Unit, and typically featured either 3 x 5 HP motors or 3 x 8 HP motors. It works very well.

I know Geoff, he is a great guy.

It is easy to get 8-10 runs at about 15 seconds a piece before draining the batteries completly. What you would find is you had boost when ever you wanted it. And when you didnt you would have a stock car... so no worries about economy... with just a PUSH of a button, go from stock to sport.... hahaha

Just use a simple setup with extra injector and you are set. YOU DONT NEED BOOST FOR more than 15 seconds at a time, unless you are on a track and even then you are not going to be under full boost conditions or need boost the entire time, unless on a straight away. In traffic forget it, but how about a unit you could install on your tow vehicle and your track car, but use only one unit... just swap it back and forth, with only the batteries and other provisions installed on each vehicle, the unit, with no belts and all that could be setup to be swapped in a few minutes... oh say from a s10 blazer with the 2.8 v6 to saw a 2.5l Inline 4... hemmm

In any case, yes its like nitrous with no bottle to fill ever! Depending on your battery configuration and Voltage you can do amazing things with it. The M62 unit and the M90(I started with the m90) flow more than enough CFM and I found that I could make well over 12 PSI with the unit.

250 Amp alternator doesnt hurt much... hahaha yea you could install a 200, 250 or less... just a matter of how long it takes to recharge... and how drained your batteries are and what kind of batteries... imagine a bank of 4 batteries... wired up for 24 volts and series amps.... can u say unlikely you run out of juice for boost? Atleast not on the morning commute... and talk about a sleeper... hahaha you running nitrous, you could certainly say no... stealth, yea... install it someplace and hide it... only thing visible in the engine bay say is a pipe feeding the intake... run that down toward the front of the car... looks like a cold air intake... unless you follow it and find a ESC installed... hemm funny thing about those letters....

You can sequentially stage the motors as well, so that each motor comes on at a specific RPM level when armed.

Why? Well depending on engine rpm and load, you dont need 15 or 18 hp to drive the supercharger. But as engine needs increase you need more, so I ran from Idle to 3k with one motor, then at 3k the second motor ran, then at 5K the 3rd. 5-8 psi easy, want more no problem... want to pass that slow moving truck thats in your way going up hill but car doesnt have the power to make it happen... press a button... easy, to easy...

Basically you arm the system and hit the gas, at 80% or more of WOT the supercharger comes on almost instantly(as in it was off and suddenly its on). Its like something kicked you in the backside).

Of course can be set to just run all three, but the drain is greater on the batteries, I prefer 24 V, cause 12volts sucks! And its easy to charge 12v batteries wired to provide 24 or 36 volts to a ESC. Higher the voltage, the lower your amp load. I still have my setup, if anyone wants me to post pics I can. But basically I have one of the first production models infact if you look here:

http://www.turbomagazine.com/tech/0406tur_knight/

Mine is the same color (powdercoated red, etc) as the one seen in the article. His little altima was something else. It had the 2.4l motor in it, hemm amazing how close that is to the 944 displacement....

I know Fast Four is doing or did and article on his stuff, Import magazine, modified magazine and a few others have acknowledged his stuff works in various articles. He also did a conventional setup "roots" for a car featured on RIDES.

In any case... he is listed typically as the only working electric supercharger. Several magazines have done install on different vehicles. You should check out his 1/4 times in an otherwise bone stock altima.

[Khal]

[CBass]

For the expense and trouble of install, nitrous seems like a better solution to me. I just can't get behind electric superchargers, because of the basic principle.

A supercharger uses mechanical energy from a belt drive off the engine directly to compress air. This design is not terribly efficient, as it takes crank hp to spin that compressor and even though it'll make much more hp than it uses, it'll still be holding the engine back from it's max potential in any given tune, not to mention it uses extra gas. An electric supercharger is even less efficient, it requires just as much mechanical energy as the belt driven blower, but it either has to be run off of it's own seperate battery bank(heavy as all hell, not good for a performance car), or it's electric motor(s), which is/are less than 100% efficient needs to be powered by the alternator, which is a less than 100% device that converts mechanical energy into electrical energy, so it can then be converted into mechanical energy again to compress the air.

Whereas with nitrous, you just need a bottle and a couple of solenoids.

I'm all for creativity in building motors, but the expense of putting together a system like this, when for hte same cost you could buy and rebuild a 931 engine and have 220hp on demand whenever you sink the pedal... To each their own.
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'81 931 in various states of assembly

[ESC944]

Yea I can agree on the expense vs. a rebuild. But what if you already have that rebuilt engine or some such.

Now lets consider that a bottle cost "X" dollars and will cost "Y" more dollars the more u use it (X+Y= total cost), ie you always have to refill the bottle. Not to bad, but it can add up, just isnt all at once.

Now yea in a performance car you might want some other form of boost, or some such. I endorse boost of any kind as a replacement for displacement!

But the batteries and the supercharger setup do not way more than a turbo setup, depending on turbo setup and batteries used. You know wght of turbo, + header, down pipe, etc...

I use smaller 12v batteries about 12 lbs each I use a total of 4, or used I should say, these have about 680 CCA each now that means I am running two banks of 24 volts basically and a high out put alternator. (200 AMP) yea you can install one easily on a 924 or 944. I could run the stock unit, but it takes longer to recharge the batteries.

All together I sunk about 1000 in the complete setup and beauty is I can take it off at will and put the unit and the batteries in another vehicle.

As for the weight I acually replaced the stock battery with one small battery and she runs great, the other 4 batteries are in the back, although at first I had 4 in the front (1 for car, 3 for ESC) and ran 36 volts. In any case for the twice the cost of a Nitrous kit i never run out of boost when I want it and I can litteraly hot swap the unit from one car to another provided that car was setup for it, or say you have this is your drag vehicle and your tow vehicle, you run it in the tow vehicle till you get to the track, then swtich over...

in a truck added weight is no big deal esepcially if its in the back for traction.. or say you vehicle is to light... screw adding ballast, I will just add some batteries....

Heck when I first got it, I just got two used batteries from the junk yard and wired it up and played, god what a rush.

And no im not Geoff. But I do like his products and consider him a friend. Super helpful guy, tons of tech support. Considering in my case, that all I got was the core supercharger and fabricated the rest.

As for effeciency, well the higher the voltage the lower the required amps. So if you run 24, 36 or more... well it rocks.

I would love to set it up on a hybrid vehicle like the Ford Escape, where you have higher voltage and batteries... and all that recharging... add a little boost and you get more power and not much in the way of a loss in performance, even at 3 PSI you would see a nice increase.

As for the current model of SC well they are better than the roots and since their is no spool up required just instant on.

Anyway, most people have lots to say against it, but it works and is considerably cheaper than a retail turbo kit or supercharger kit, which is what it compares to more than nitrous.

Their are other hazards with boost and with nitrous both, so we will skip that, but bottom line, you are talking about 3, 5, 8 or more PSI on demand when ever you want it.

Nitrous adds a fixed amount of power, which can be a plus.
A Turbo, SC or a ESC, basically increases power as a percentage of base hp.

So in practice, lets say we have your 220 HP engine, you add 50 hp of nitrous, that gives you 270hp.

using a few different hp calculators I come up with an average of 265 Hp at 3 PSI, 295 Hp at 5 PSI and 325 Hp at 7 PSI, of course those numbers could be off.

I found that at 3 PSI I only need water and alchy to supplement the fuel, you could of course use a 5th injector for fuel, which I did.

So off boost, stock performance and economy, on boost more power and less economy, same basically as Nitrous as you pointed out, but the SC isnt flamable, isnt under pressure. Oh and even the nitrous bottle adds some weight.

Needless to say, buy what you want from who you want and enjoy.

I personally love the ESC even the older versions, the new versions are better, more effecient etc and it will continue to get better.

With the right combo of batteries and alternator its like never running out of boost. Considering the limits of traffic and the daily drive. Nitrous runs out, when your batteries are low, just drive or run the car and recharge.

Its not perfect, but it is cheaper than conventional sources of boost on the market. Excluding the DIYer.

[RIPDOTCOM]

Figured I would jump in here and let you guys know that I used to run an ESC350 on my 1.8L Escort GT (miata engine to the rest of us ) Using 2 X 680amp 13Lb odyssey batteries running at 24v I was able to make a 1/4 mile pass with an et of 15.8 seconds. Keep in mind that an escort GT is a 17.8 second car. This was on street tires with light bolt on mods. It does indeed work and very well at that. Unfortunatley the volumetric effeciency of it kind of conks out around 5500Rpm (on the 1.8L BP anyway) but it is as effective as say a 35-50 shot of N2O and a hell of a lot cheaper in the long run. I have since sold the GT but may put it in my 1.6L MR2 as the 2.5L breathes too heavy for this unit and would probably only make 2-3psi.

[N-Dub]

Today in my autoshop class I "supercharged" my friends Escort with the compressor for a Big Rig air horn. Just ran the air hoses in to the intake before the MAF sensor, so some extra fuel was added. It worked just fine until the old compressor burned up.
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'79 924 now Totaled! Carrera GT bodywork for sale!
'87 951

[wuilman]

wow, i havent been on here for a while. and the last time i was here people were trashing the living he11 out of the whole electric supercharger/blower idea.
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wonder what this button does.......oh!

[simsport]

As I have a blower and figure I can speak with at least some authority on how they feel I can honestly say they will never give you as much 'kick' as a gas setup or even the push in the back that a well matched turbo will give. Blowers cost more and do use some power to run.

However I feel this is missing the point.

Superchargers provide 'area under the curve' meaning power when its neeeded and not just as the revs increase to an effective point. Hence a gas setup with a demand valve that opens at full or near full throttle will never be as useful from A-B. Nor will a peaky turbo setup, although both of these may make more outright power for less initial purchase cost.

SBASS is developing his car with what we all hope will be an effective turbo which will make boost from very low revs and avoid as much lag as possible. If he achieves that he has supercharged his engine! ....but of course he has the addded advantage of more peak power.

I have driven very high power GTIR Pulsars with big turbo's, 944T's with 300+bhp and my car with its 205bhp and Eaton blower cannot compete in terms of rush...but will kill them stone dead when a bend arrives, better still when there are a few one after the other.

I love the rush of raw power as much as the next guy, but do hope more people do go the supercharged route so we can develop them still further.

Cheers
Simon
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Blown is always best!

[endwrench]

I'd just like to echo what Simon said. My car is not really in the same league as his but I think the commen link is an extremly flat and high torque curve. Mine is mostly street driven so I can't really tell you it is faster than comparable turbo cars as street cars are so rarely driven near the limits of adhesion but I can tell you it is a pleasure to drive. No need to shift down for highway passing or winding out before shifting up. I've driven my share of turboed street cars and I do like the "rush" a turbo gives but for everyday driving I think I like the super better. No need to time out when it will spool.

I've driven Twin Turbo Supra's. They have almost no lag as far as turbo cars go but it still seems to take decades compared to my setup wich is not completly lag free itself with all the plumbing I have. The one HUGE draw back my setup has compared to a turbo setup is noise. The intake system is ungodly noisy. I think I can fix some of it when I go to GT headlights but it will never be quiet.

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....