I know that there has been some talk on other threads about this topic, but I didn't actually see a thread labeled for this. So I figured why not make a discussion topic about it to get people general thoughts about it and opinions.

The Phantom Supercharger is a full throttle electric supercharger, BUT WAIT!!!! it is NOT I repeat NOT the p.o.s crap from ebay! It utilizes the power of a Brushless technology in a electric motor that is mated with the compressor side of a turbo. To be honest the thing gets up pretty high in rpm. Also it is designed for scion frs and VW and silverado trucks. So WHY post about it in a rx8 forum??........ I don't know, just for kicks I guess.

**EDIT** I put this in series I major HP mods, I guess it would go elsewhere since it would be a general discussion**

the website can be found here where there is all sorts of information such as dyno charts, Technical info, and the compressor map. (I have read it all)

New site - HOME



Here is a bench test of the product.


When installed the system is supposed to generate about 5psi of boost for a minute or so then the system will need to recharge. Unfortunately I believe that it only initially produces 5psi and as your engine revs higher it slowly drops to about 2-3psi.


Here is a install video



and it can be installed on other vehicles, here is a guy who has installed it in a mazda 3. This guy also has another video of him running the back roads and the system kicks in quite well.



if anybody would like to actually see this on a frs then this is a video of a nice frs with the kit installed.



and lastly here is a link to the forum where there is pricing and a ton more videos for anyone who is interested.

Full throttle Electric Supercharger Build Thread - Scion FR-S Forum | Subaru BRZ Forum | Toyota 86 GT 86 Forum | AS1 Forum - FT86CLUB



On another note it certainly would be interesting to see this on a 8 and working. I mean the most this thing can produce is 5psi which is about what the stock seals can handle anyway only thing you would really need to do is tune for AFR cause I am sure with this on a stock tune the car would run super lean, as it shows this on some dyno charts for the frs. I guess if you're an average joe who would want a little more power for passing or for better off the line starts then this might be beneficial. Don't expect to put this in and feeling like you can take on Lambos or Gtr's lol.

 

The stock seals can only handle 5psi? Crap..I guess I was doing it all wrong at 16psi :P


:lurk:

 

The 110*C safety shutdown might be an issue in an RX-8 engine bay ...

 

Unlikely, that's a junction temperature and if any part of the controller is getting that hot under any condition the motor's windings have probably burnt off their insulation and shorted together.

I have no doubts that a proper kit like this would work, the issue I still have is that it can't be used continuously and it's dead weight and an intake restriction most of the time. Also, I'm not familiar with FI but 5psi doesn't seem like anything to get too excited for.

It may be worth noting that the FRS uses ~160g/s of air NA at redline (7500rpm) while we use ~200g/s NA at redline , so boost would not be anywhere near as maintainable.

 

5psi is like a highly tuned NA RX-8 making 220WHP or so. Based on my butt dyno.

 

Well I can say with some certainty 4psi is much better than no psi. I can only assume 5psi is even better.

 

But if you can that much with tuning+some weight reducing intake/exhaust mods why would you choose to do it with a heavy E-SC setup+tuning?

So that it can sound like your air pump is stuck on at WOT?

 

I think the system is designed to kinda idle when its not being used. The impeller spins at a lower rpm for normal driving and highway use. Also from what I have read the stock seals could handle about 5 psi. If it's wrong then I'll change it.

 

Unless is spinning at or above the required speed to maintain the flow that the engine's taking in then it's causing some restriction. I don't know how fast that is, but maybe it's an adjustable thing?

 

110*C = 230*F = common RX8 engine bay temperature

Unless you're proposing not mounting it in the engine bay ...

 

It say:
"Partial activation is triggered with sensor to retain stock intake vacuum"

They have a interesting concept. Pair with a turbo to fill in top end

 

Electronics will hit the wall first if they have the same temp. Normally windings can handle up to 180°C. Capacitors and semiconductors can not. And at 100°C, component lifespan, especially non ceramic capacitors, will be drastically shortened.

 

And if it can't maintain 'boost' anywhere near peak HP (which seems likely from it's flow rates vs what our engine wants to flow), chances are the peak HP number on the dyno wouldn't actually change over a stock 8, perhaps even a slight decrease from the restriction. I'd expect that the main area it would affect would be lower RPM. Probably a slightly faster car overall, but not any higher peak power.

 

I always wanted to try something like this .
I was thinking of running a diverter plate that kicked in once the ESC ran out of puff .
5 psi from low rpm would be pretty nice IMO.

 

I certainly think it would be interesting. That would be a good idea to have something like the VFAD except it would be located after the blower and to have it open at like 5-5.5k rpm to eliminate any flow restrictions. I'm like Brettus 5psi would be nice on the low end.

 

I like the idea, somebody should give it a shot correctly. I don't believe the under-hood temps get quite that hot with the car in motion, although they might get close at a standstill. I haven't recorded under-hood temps, but I can say that my hood has never been boiling hot, maybe closer to the 150degf range.

Who's gonna try it?

 

Would probably be a nice safe improvement with street driving benefit. Also doubt it will hurt top end performance. An NA engine is relying solely on atmoshperic pressure to fill the chamber. In this case there will be a fan pushing a out the equivalent of what an NA Renesis needs. For most I'd expect a small increase at high rpm with a solid improvement at low rpm that tapers off. All the dyno graphs on these systems show this general trend. Engines with smaller airflow demand show more improvement across a wide range. Larger engines show less gain as they approach the compressors limit. Supposedly are working on a larger 24V unit, might be a better fit for more top end flow. Here's a 4.3L V6 engine dyno, it went flat at peak so even if you lost on top you gain a lot down low to offset it:

 

found this calculator for power required for compressing air. As this isn't my field of expertice, it could be wrong for us, but seems like weight of air is around 1.19g/liter. 100g/s give us 84l/s = 5042 l/min. Sheet say that you now need 4.2kW at 71% compressor effeciency, and 1,33B(5psi). This translates to 234A at 24V and 75% effeciency at motor. Kind of makes sense to me.
http://www.scubaengineer.com/program...calculator.xls

 

^ that's more accurate than I've napkin mathed, but yeah, eSC requires more power than most people realize to actually build pressure, and the capacitor/battery needed to generate and hold that kind of flow is self-defeating.

Of course, if someone were to stick a turbine in the exhaust streem somewhere toward the back of the car that drives a generator directly that can fill the capacitor, then it would be an eTC, but probably more sustainable than an eSC in that you could, in theory, provide all the amperage needed at WOT, vs trying to store up a full WOT charge to maintain.

Of course, there would be greater losses for converting the thermal energy to the mechanical energy spinning a generator to the electrical energy driving the motor to the compressing mechanical energy...

... than there is for converting thermal energy to compressing mechanical energy directly.

But you would save weight in piping (even if some added back by cables/capacitor) and it would be more easily distributed throughout the car, so packaging is less of a problem.

 

RIWWP, I think you are looking at it from the wrong perspective, you need to look at it from a performance angle, not fuel saving angle(Lets be honest, we would not have been buying a 8 if that was the case). If you are using electrical power, you can harvest energy in times when your engine have something to spare(not WOT). When at WOT, you can use this accumulated energy to increase your performance. So MPG will suffer, but we don't care about that, we want powa!

If you had an exhaust driven generator, you could potentially increase MPG as well, as this is wasted kinetic energy. Very close to a turbo really.

 

That isn't the way I was approaching it, but I need a real keyboard to clarify

Posted From RX8Club.com Android App

 

just gonna leave this here

not a phantom but the same "boost" and "stats"

 

I view most power adders and fuel efficiency adders as much the same thing There are very few things that add power that couldn't be adapted to increase efficiency instead, and there are very few things that add efficiency that couldn't be adapted to increase power instead.

What I was referencing in my post was the power side.

A while back I was doing some math and digging on the possibility of harvesting exhaust energy and sending it directly to the drivetrain via an electric motor. What I ended up finding is that with current technology you can only harvest about 4-6% of the amount of power that the engine is currently producing. So at cruise for the RX-8, that would only be somewhere around 2whp, at full throttle it is more like 10whp. Even today's turbo technology is only harvesting somewhere around that much energy. Turbochargers/superchargers are just using their energy source to compress air, the rest of the power being delivered for those applications comes from the energy content in the added fuel.

So reversing that around a bit, basically in order to produce positive pressure at full throttle, peak N/A power point, whatever the turbine is, it has to consume energy somewhere in the 6-10hp range. I'm not throwing precise numbers at it, since the amount of boost changes the exact number considerably.

It's why those fan motors in sonic's post don't work, because they use only a fraction of a single horsepower. So even if you get an electrically driven compressor, you will still need to supply that a quantifiable level of horsepower to compress the air. So that is why I say that your 4.2kw is a very believable number, as that is ~5.6hp.

The only real difference between an eSC and an eTC would be the same primary difference between a normal SC or a normal TC: Where it gets it's energy. And if I was going to build one for power, I wouldn't rely on a capacitor to store up a single WOT run charge. It would have a rapidly decreasing amount of power behind the compressor while the demand for energy is rapidly increasing. It's not a good combination. Instead, I would try to harvest that energy directly from the exhaust, since the amount of power being provided to the compressor would be increasing as the demand for energy is also increasing.

You could still have something similar to F1's turbo tech, in that you can use a capacitor to pre-spool the compressor, boosting low end torque, and that capacitor you could slowly charge up even during cruise or at idle, since you can still harvest the lower volume of wasted energy.


But then that all gets back to my prior point. Converting energy always has a loss % associated. Converting from thermal energy(exhaust) to mechanical energy(compressor) is far fewer points of energy loss than converting from thermal energy(exhaust) to mechanical energy(generator) to electrical energy to mechanical energy(compressor). So a traditional turbocharger would still be 'better' from a mathematical perspective. The primary advantage that such an eTC would have would be that you can mount the generator farther rearward for better balance and to avoid clearance problems at the exhaust ports of our engines (with corresponding loss in energy because of the cooling of the exhaust over that distance), and that the connection between the generator and the compressor no longer has to be a mechanical one, so even the intake side packaging becomes significantly easier.



Does that make a bit more sense?

 

I love MCM too!

A little different though.... that is just a fan in the way of airflow, even if it moved the air faster... it's not compressing it. The turbo attached to an electric motor has a chance of actually compressing it.

 

Interesting discussion, and yes, I agree. And not Might be a language barrier here, but anyway...

As they say, on a trackday, this concept eSC would be problematic/not very beneficial, due to insufficient electrical charging and close to NA peak HP. But for normal driving, I still think that there would be performance gains; They state that charge:discharge ratio is 1:8. So if you are charging/using 1hp, and have say 50% total efficiency, you will have 0.5hp/sec of stored SC output. So the 1:8 ratio sounds realistic to me. 1hp means approx. 55A@14V. Normally an alternator can handle this. So I do not see an obvious error here.

On top, you can see the pressure drop immediately when RPM increase, because motor only have enough juice at quite low flow. So at 20lbs/min its down to half pressure, the electrical motor cannot deliver more than this. If you run constant electrical power, then pressure will decrease in a straight line, as the flow increases in a straight line.
TECH - New site

If you want a trackday car, combining a eSC with a normal mech driven SC seems like a attractive option, I believe this is what this guy did. Here you can also see the almost ruler straight line with pressure decreasing when RPM increase. Wild Weasel Tests An Electric Supercharger