Electric supercharger

[Moridin]

I know, I know...electric superchargers are all crap...blah, blah, blah.

 

Well, I came across an ad in Sport Compact Car that looked promising.

 

Here's the link: http://www.boosthead.com

 

I may be looking into this for some TQ on my Honda motor. Be awesome if I could set it up for full throttle, below full boost RPM, and have it role off as the turbo worked its way up to full capacity.

[baddriver]

This does look like a better system than the bilge-pump BS that was going around earlier, but for 2 grand, couldn't you get a full-time blower? What's the advantage of not having it driven off the motor?

 

I suppose It might be nice to be able to bolt it onto a different car down the road. Of course you could always sell your supercharger and get one that fits another car. And the 2K doesn't include any fuel delivery solutions. Still need to solve that problem for each application.

 

It's tempting though. I really think you should get one and tell us a little more about it.

[Moridin]

Maybe if I get the money I will. The real cool thing about this, is that the power really will be almost instant. If you look at most superchargers, they just raise the power curve, not change the shape of it. With a Honda motor, there is so little torque down low on the 1.6L that it's not even funny. Its only good for 15 seconds or so, but I'd only be using it to beat up on a few Vette's or so. My motor is already built for boost, so I don't think it would cause much of a problem. Hmmm...I think they're located in California. They give test drives in their 4 cyl Altima. May have to make a trip down there.

[SleeperZ]

Sounds like that setup is going to weigh in about 100lbs. Theoretically it should be able to make a positive difference to your power/weight. My concern with that thing is the compression efficiency - if it's not at least as good as a roots charger, you will need a good intercooler, and you could drop significant pressure in the IC. That would make it quite a bit less effective than a nitrous system.

[Moridin]

I'm not exactly sure how efficient it is, but it does flow 405CFM at 5.5PSI. It's looks to be roughly the same blower (maybe a bit bigger) that is on the family's Cobra.

 

I think I'm going to give them a call sometime next week to have chat.

 

The electric alternative to nitrous.

[blueovalz]

From what I can see here, it is similar to the GM or Ford supercharger except that this is powered (or spun) by 3 DC motors. Interesting approach. I've seen many motors similar to the 3 shown in the photos (I use one very similar as the motor for my rotating spark gap on my tesla coil). If these are permanent magnet motors I would be concerned about underhood temperatures and it's effect on these motors.

[Guest bastaad525]

I was really interested in that thing too... it definately sounds 3 leaps ahead of any similiar products I've seen advertised. I was thinking of one as a means of boosting low RPM response then having it cut out when my turbo's own boost kicked in, similiar to a low hp nitrous setup that would be used for the same thing, say, from launch to 2500rpm.

[Moridin]

I was thinking about using this for my Honda, because its not RPM dependent at all. Very nice for making some torque. Just plumb it with the turbo through the intercooler.

 

I'm also wondering about heat issues with the DC motors though. I wonder how hot they get, and how that affects the blower performance.

[baddriver]

Hey,..Hey,..Hey... Makes me want to go home and watch Mad Max. Click, bye!

[auxilary]

2 grand? for that? uh.... pass

[Guest BigWhyteDude]

Sorry to hyjack the thread guys but, How big was your tesla coil Terry?? A friend of mine built one that was about 2 feet high, and gave off enough radio waves to fry his phone, microwave, electric clocks, and most other elextrical gadgets in his home. (He set it up in the living room) Untill his wife told him either it had to go or she would. It was freakin awsome to watch those bolts of electricity.

 

Andrew

[blueovalz]

Some pics of it are on on my fototime link. It fried the electronic dishwasher controls, caused the refrigerator's in-the-door ice and water dispenser to throw ice and water all over the kitchen floor every time I turned it on, and killed several solid state devices in the house, all from outside in the garage going to 2 six-foot grounding rods in the yard.

 

Curiously, I took a picture of a 5 foot streamer arcing to the roof of my Hybridz, with arcs coming out of the wheels, over the tire's sidewalls, and into the concrete floor as a "battery charger" humor shot, and not a single solid state ignition part was destroyed. So who knows.....?

[Pop N Wood]

Why not hook a small gas turbine engine to the blower? That way your engine develops beaucoup HP without no power loss to drive the blower. Or if you only want 15 seconds of boost, connect a solid rocket motor to a turbo. Use the stored energy in the rocket to as a consumable power source (instead of the batteries this system uses).

 

18 HP of DC motor isn't going to move too much air. Don't typical blower assemblies consume hundreds of HP from the motor?

 

The big question I have is what type of bypass assembly does this system have? You wouldn't want to be drawing air through the blower when it isn't engaged. Thus you need some type of damper/valve system to shut off the normal intake track when the blower is on. Also you will need to switch back to the normal intake path when the blower runs out of CFM. The thing says it is rated at 405 CFM @ 5.5PSI. This isn't going to supply even a Honda engine at high RPM. How in the hell could you produce 425 HP with only 405 CFM of air flow?

 

Putting flow restictors in the intake tract will have a big impact on the NA performance of the engine. He doesn't mention how to do this in his ad.

[Moridin]

The thing is rated for 20 psi of boost, so 5.5Psi is only getting started (assuming the compressor's effciency doesn't drop off dramatically after 5.5 psi). I'm pretty sure there is some type of bypass assembly, but one could always be fabricated without too much effort, because I would have it roll off as the turbo was working its way to full boost.

 

The thing about using batteries is that they are almost instantly rechargable. In any street or drag situation where you need power before boost, then the electric system is ready to go. Then, for your next pass down the strip or on the highway, the system is fully recharged and ready to blast.

[SleeperZ]

The thing is rated for 20 psi of boost' date=' so 5.5Psi is only getting started (assuming the compressor's effciency doesn't drop off dramatically after 5.5 psi). I'm pretty sure there is some type of bypass assembly, but one could always be fabricated without too much effort, because I would have it roll off as the turbo was working its way to full boost.

 

The thing about using batteries is that they are almost instantly rechargable. In any street or drag situation where you need power before boost, then the electric system is ready to go. Then, for your next pass down the strip or on the highway, the system is fully recharged and ready to blast.[/quote']

 

Just because it's rated for 20 psi, does not mean it is efficient in that region. Superchargers typically ARE NOT. They are designed for much lower pressures, usually upwards of 10-15 psi. If I were considering that system, I would insist on a flow map, similar to the flow maps that document turbocharger compressors.

 

I would guess the batteries are recharged by the alternator, and there is an alternator cutoff switch wired into the throttle, so you don't get the parasitic drag associated with charging the thing. It certainly will not recharge "instantly" -- depending on the type of battery and the current limit of your alternator, a full recharge could take from about 5 minutes to upwards of an hour.

 

I like the idea of a liquid or solid rocket fuel to drive the compressor. In that case, you could use a standard turbocharger, and drive the turbine independently of the engine exhaust. I'm betting it would be substantially lighter than batteries.

[Moridin]

The thing is rated for 20 psi of boost' date=' so 5.5Psi is only getting started ([b']assuming the compressor's effciency doesn't drop off dramatically after 5.5 psi[/b]). I'm pretty sure there is some type of bypass assembly' date=' but one could always be fabricated without too much effort, because I would have it roll off as the turbo was working its way to full boost.

 

The thing about using batteries is that they are almost instantly rechargable. In any street or drag situation where you need power before boost, then the electric system is ready to go. Then, for your next pass down the strip or on the highway, the system is fully recharged and ready to blast.[/quote']

 

Just because it's rated for 20 psi, does not mean it is efficient in that region. Superchargers typically ARE NOT. They are designed for much lower pressures, usually upwards of 10-15 psi. If I were considering that system, I would insist on a flow map, similar to the flow maps that document turbocharger compressors.

 

I would guess the batteries are recharged by the alternator, and there is an alternator cutoff switch wired into the throttle, so you don't get the parasitic drag associated with charging the thing. It certainly will not recharge "instantly" -- depending on the type of battery and the current limit of your alternator, a full recharge could take from about 5 minutes to upwards of an hour.

 

I like the idea of a liquid or solid rocket fuel to drive the compressor. In that case, you could use a standard turbocharger, and drive the turbine independently of the engine exhaust. I'm betting it would be substantially lighter than batteries.

 

I definitely understand compressor efficiency (said so in my previous post ).

I'm not sure about the batteries. I thought I recalled reading on the site that they recharge very, very quickly. My idea is to get the supercharger going (supposedly full boost in less then half a second) to add some much needed torque to a small displacement engine, then roll off as the turbo kicks in. Same idea as using nitrous, but you don't have to worry about filling the bottle.

[Pop N Wood]

I got thinking about this some more. The site said the blower is driven with 3 DC motors putting out a total of 18 HP. With a 12 volt system it will take 65-70 amps per HP. Thus driving all three motors off one big ass battery will draw over 1200 amps. No way.

 

If you use 3 separate batteries (one for each motor) you will still draw over 400 amps/battery. That is like running a separate starter motor per battery. No way will a car alternator charge up 3 full sized batteries in a hurry. In fact, you had better put some type of smart battery charging circuit to keep from overloading the alternator and/or causing an excessive voltage drop.

[Moridin]

Doesn't the amperage draw depend on how efficient those DC motors are? Under the FAQ section for the site, they actually give a calculation for how fast the batteries should recharge, given the amperage rating of your alternator. At first, when I read, I thought it said one to three secs for a full recharge. It was actually one to three minutes. I'm not sure why I thought of it in seconds, or why I didn't wonder how it was so quick.

 

So...what we really need to see from the company is:

 

1. Flow charts

2. Dyno charts (they're available already on the site)

3. Amp pull of the DC motors

 

Anything else?

 

Oh...I know they use the little 13lb Hawker batteries for their system. Three of them if I remember correctly.

[Pop N Wood]

The 65-70 amps per HP assumes near 100% efficiency. Less efficient motors or figuring in the voltage drop in the cables/batteries will increase this number. Older/slightly discharged batteries will increase the current requirements even more.

 

2-3 minutes to recharge...don't know about that. Depends how long they were putting out 400+ amps. Batteries are rated in amp-hours. This number goes down drastically as the amperage draw increases. A battery capable of putting out 10 amps for 10 hours (a 100 amp-hour battery) may only put out 100 amps for a few minutes. Thus it is going to take a lot longer at a low current to recharge even a short high current draw.

 

Also keep in mind your car may have a 90 amp alternator, but you are going to need a good portion of that to run the car itself. If the site used the full alternator capacity to recharge the batteries, then that is not accurate.

 

The other thing I thought about is engine management. Too much boost at low RPM could be deadly. With a belt driven blower you have some protection in that the blower speed is locked to the engine speed. With a separate drive system you will need something smart enough to manage the boost.

[Guest livewire23]

Depends how long they were putting out 400+ amps. Batteries are rated in amp-hours. This number goes down drastically as the amperage draw increases. A battery capable of putting out 10 amps for 10 hours (a 100 amp-hour battery) may only put out 100 amps for a few minutes. Thus it is going to take a lot longer at a low current to recharge even a short high current draw.

This thing is only going to be running for 15 minutes, so we're not talking huge amp-hours here. This sounds feasible to me, I'd like to see those figures. Also, there was some mention of the cfm's in the FAQ.