jasonrxeight

it reads 5psi on the gauge but it actually is with respective to atmosphere pressure, which is about 15psi. you need to add your pressure on top of that to have more power.

badinfluence

I figured all would compensate for this as such. The good news is most of the testing for this was done at Sealevel so it is pretty accurate for my build since I am also at Sea Level.



Throwing an idea out there to use Supercaps instead of batteries. The Power is passed through a PWM Motor Controller anyway, so the caps might be all I need. They weigh very very little. You can replace your car battery with them and it weighs less than a pound. I would want two 72-96v banks, which would amount to about 10-15 pounds, but that is nothing. The battery budget is around 1k if even. The primary disadvantage is discharging over time, but that isn't really an issue for the application. Another big issue is our Alternators aren't normal alternators. They use Frequency to dictate charging rate. They aren't the kind to just up "upgraded" like 90% of the alternators on the market. I am not sure the effect the caps would have if you tried to replace the battery with them on our cars, so I don't recommend trying that. Just wanted to throw that in there.

The primary issues with standard lead acid batteries are the purposeful high resistance. Very little resistance would be dangerous for car electronics, so a small amount of resistance is added in the form of less conductive pathways in the battery. This is what determines "cranking amps." More conductive rods = more cranking amps but less battery life. My idea was to use some 16ah VERY low resistance batteries for this project to keep the weight minimal and power maximum. 100 pounds max was the estimate for all the batteries.

Some people think this resistance adding is a bad thing. Well if you do, but one of the lower resistance batteries and short it.(Don't do it, youtube it) Trust me, you will want that high resistance after you see a hydrogen explosion out of a battery.

badinfluence

I am not sure how many people have heard of the Phantom Electric supercharger, but it is been tested on the FRS. It is basically a Turbocharger with the exducer cut off and a R/C type ESC driven motor replaced in it's place. I think they are being a little generous with the efficiency.

FTS-TQ25024V - New site

This setup is basically 4KW to produce 2.5psi of boost. That is a real world adjacency I can use to see how mine will go. I applaud them for making it a kit, but for <70% Efficiency, that is kind of a waste. They would get a much better number if they changed the motor to a higher voltage, and switched compressor styles.

badinfluence

Ok I have been playing with the ESC device since it showed up, and I have learned one thing: This is to much for an RX8 to handle. That is exactly what I was aiming for, too much.

Total power is 18HP for the Electric Motor at peak voltage, but even at 12volts it had enough torque to try and escape the bench. I am having to postpone testing till I can build some kind of holding device.

I have been developing the Motor controller myself from almost scratch. My father chimed in and gave me a big push when it came to what transistors to use, but I have mostly been planning the power mapping out myself. I am still going to use SuperCapacitors, but I am going to use a unique way of gating the Boost converter (not boost controller), so it won't have more amps and volts than it needs at the given time it is operating.

The ideal Supercap is the Maxwell 3000 Farad in 2 banks of 30. (200 Farad Total.), but since they have become known to the world the price has gone up severely to almost 64 dollars a cap. This isn't ideal for a prototype, so I am going to use 12v 20ah batteries and some 350F caps to test with.

This is going to take a whole new kind of Dynotuning, so it will have to wait till I get the PC interface built for my custom power adder computer done. Right now it can only be programmed by a Basic Stamp and a USB cord with a computer attached.

Pictures are coming, but I want to control where they hit the internet, so they will be hosted inhouse.

xsnipersgox

I'll follow this thread, in houston too so i'd love to see it when i can. My only issue is mainly with my distrust with anything electrical and the known abundance of large amount of wasted energy in the rotary exhaust stream.

what kind of compressor you going to use?

badinfluence

It is a Root Type. Twin screw would be to unpredictable, and a centrifugal takes way to much rotation to do anything with it. Also the centrifugal takes way to much balancing of the inducer if you don't have the bearing assembly, and if you do, you have to worry about oil or the bearings for cooling and lubrication. There isn't any room for a transmission or drive ratio adapter, so your motor would have to spin several thousand RPM to get any non parasitic boost.


I tested the supercharger this weekend on 12 volts, (I will be running it at 84), and it moved pretty good at 12, enough to scare you. 24 is supposed to be it's minimum voltage so I didn't want to leave it at 12 for very long, plus it would be drawing a ton of amperage at 12 and cook the battery it was connected to.

For now I am going to get a 72 volt golf cart controller and 7 20ah 12 volt Sealed Lead Acid Batteries till I can find the motor's speed curve at 72 and what it will take to build positive boost and what it will take to move air at idle.

AAaF

If you use a motor, you are independent of engine speed, unlike pulley. Massive advantage.

In my work I've seen watercooled permanent magnet motors running 7.5t@ 2.5m/s, that means 187kW continuous if im not wrong. It was actually not that big, but fitting it into an engine bay would be a challenge.

Problem I see is power delivery to motor from dynamo/accumulators, and weight/space.

badinfluence

Good news for all of that. At the end of the day it will almost break even.

I am removing the stock airbox, stock battery box, stock battery, and anything else in that area to bolt the supercharger up.

It weights about 50 pounds total, so that nearly breaks even.

The battery will be replaced with super-capacitors near the windshield wiper tank. eliminating some necessary wiring length, engine load, & space.

The supercaps weigh less than 2 pounds total for the board and the modules assembled. They are about the size of a small brick.


For the 72v/96v size I am using a create way to pulse DC-to-DC converters so they draw less total power per second than if you straight powered the motors.
so it does 12v Alternator (200amps) to Supercap bank #2 to DC-to-DC (round robin 1:6 Ratio) to motor controller(PWM), to motor.

So here is where I am at right now. I am testing it off the car, and working out the motor's calculations. The car is stock and still under warranty for now, so I want to wait and see the Engine's health before I start dynoing/testing. Right now the engine is getting worse and not starting well. I want to see if it will get to low enough compression to get replaced and then start this process. That will also give me a chance to strengthen some things such as the exhaust mani & coils.

Right now I am going to do 7PSI at 2500 RPM tapering down to 2PSI at 6000, and +/-0 pressure at 8000RPM.

badinfluence

Was that a 3 or 4 wire perm motor? If you make the contact points supercooled by water, the motor's fan and balance can be smaller because of the less space needed. Also that prevents the motor's dust from Atomizing.

One other question. Was the 7.5t, was the T a typo or a unit? I wasn't sure if you meant electric KW or power KW. Example 187,000watts (electric) or HP(as unit of power, not electricity)

There is a place in England that is making some amazing electric motors that are watercooled and are 4 wire controlled for extreme precision and regeneration control. You must buy the whole kit because of how customized it is, but that is ok. I have to find out what they were called again, but last I checked they were trying to make a "drop in kit" for an EV conversion.

jasonrxeight

good luck finding 187kw of electricity too. stock alternator is 1440w, so you need 129 alternators to continuously feed the supercharger, if you use less, think about batteries.
there is a reason why superchargers are driven off the engine because electricity is not the most efficient way of delivering power.
any why would you want independent of engine speed?

I am not saying its not doable. anything is doable given time and money. it all comes to weighting pros and cons.

badinfluence

I dont think he was insinuating that at all.

187KW is 200HPish or 90PSI of boost if you can get a compressor to compress that much. My guess is that is for an EV and he was just saying the technology has come a long way.

Independent of the engine speed means direct boost anywhere without any restrictions or need to take power from anything including the alternator.

badinfluence

-_-

badinfluence

-_-

Stray

Sub'd. I've seen something similar on the FRS/BRZ forums used with great success.

badinfluence

I actually called the owner for some information and at first he dismissed my idea, but after I explained it to him he was interested but a bit skeptical. I would say you could you that same model on the RX8, but it doesn't flow enough for anything past 6K RPM, where as the M90 will flow all the way to 9,500 RPM on a ported Renesis. It will draw a ton of power, but will keep going. I plan to just keep it under 6k right now to keep the power usage minimal and the torque temporary to where it is missing int he curve.

The same place I got my M90 version from was the original design for the BRZ model. He stopped using the Centrifugal type (Turbos, Superchargers, and ESCs) for the rotor type because the Centrifugal have to spin at XX,XXX RPM where as the M90 does about 2,000 RPM max. More torque is required, but the parts last longer and require no transmission to make the wheel spin as fast as required.

Harlan

iTrader: (3)

Super caps aint gonna cut it, at least not with the size/weight constraints you're talking about. I expect you will want the supercharger to run for >30 sec in a single pull, not <15. I don't have the math handy, but I was considering super-caps as a battery replacement. When I figured out there would only be enough juice to crank the car a couple of times I threw out the idea. Don't look at the total power available in the cap, look at the amount of power available from peak voltage to minimum voltage. As soon as you start discharging a cap voltage drops off, as opposed to a battery where voltage stays around whatever the cell chemistry produces until it's fully discharged.

Other than that I like the idea. Keep us posted.

Harlan

iTrader: (3)

Ok, just looked at several supercaps. Six of the Maxwell 3000F would make a decent battery replacement. It would be enough to run a supercharger for a little bit, but it would be an expensive prospect. The 350s would only give you one good crank, so forget about them.

Oh and any PWM pump controller for W/M injection is a joke. The sureflo pump will not provide variable flow, at least not in a linear fashion. Pressure will just bounce off the pressure switch setpoint even at reduced PWM and then will start dropping off FAST when the pump can't keep up with demand. Also flow through an nozzle is not linear with pressure so you will end up with 70% of the flow at 1/2 the pressure, or half the flow at 1/4 the pressure. Not good, not easy to tune around.

As the pump bounces off the high pressure switch, even without the PWM, it will cause flow out the nozzle to surge as pressure surges.

If you want to go that route use a water hammer arrestor as a mini accumulator and use solenoid valves and nozzles to stage your injection. That will give you predetermined amounts at predictable times.

Oh and if you're set on getting a PWM controller, just let me know I have one in my toolbox that you can have for next to nothing. (What it's worth.)

badinfluence

Based on your comment I think I left something out in between. I would be using 36 supercaps in series, (90 Volts 10 Farads) and possibly two sets of 36 (90 volts 20 Farads) in parallel. That would be the primary bank being charged by a round robin DC to DC boost converter set of 6 (200watts each running at a 1/6 duty cycle) that would work on a 1/6 distribution. At some point I am going to need a battery type and an isolation circuit to prevent from frying the alternator. I am trying to break it down in a format that I could post here, but I have noticed some of the math on the supercaps just isn't matching up. I don't want to look stupid by posting bad math. The Farad to Joules conversion isn't matching up in some of my tests because I think it is tailored to what you were saying about the battery peak to dead voltage. That motor will keep running all the way till about 5 volts before it burns up the traces on the board, so my voltage range would be from 90 to 5 volts which is huge. I took the calculations and formulas I found, and tested them with the exact load I put into the math and the load lasted 4 seconds longer than the math said it would, even with the amps on the meter being correct.

Something left unsaid on those caps is that at 2.5 they have more power than at 2.7 or 2.3. 2.7 is their peak, but they just don't work as well after 5 to 20 cycles at 2.7volt vs 2.5. All my math is using them to a max of 2.5 so it appears that, that is working in my favor.

The biggest problem with the 350s is their weird *** contacts shape. The negative is in the center and the positive is a half inch away. I think I would need a 3D printer to try and make something to hold them. A huge benefit is they are not marked up 200% like the 3500s because of Laserhacker's video. Even if you can fit them together you need a balancing circuit across every cell, so that is a difficult one to do with their weird *** shape. I thought about trying to make my own board with this as a template. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=301224051229I bought one and tested that 350 kit. I started and ran that supercharger off it. I stopped because I didn't have a shunt to figure out the amperage. It would have melted my meter's amp capacity in a second.

Harlan

iTrader: (3)

Here are some links to make your life easier:
http://www.electronics2000.co.uk/cal...calculator.php
(I'd run it twice once for peak voltage and once for minimum voltage then take the difference. You do not want to run all the way to 5volts, unless you want huge motors/wiring. The current draw at 5volts is going to be HIGH. Hence the traces burning up, the motor would be next.)

Joules to watts (W) conversion calculator
Then convert.

It's going to take serveral KW to run the supercharger (5-10ish). Also the boost converters will be inefficient and running at 200w total, or maybe you meant 1200w total (the 1/6 duty cycle comment is a bit confusing), so it will still take a while to recharge your cap bank.

I'm not trying to discourage you, but just pointing out that the math has to work out on paper before you can hope anything else will.

Also don't miss what I wrote on PWM water injection pumps. I'm serious it doesn't work worth a darn.

badinfluence

I am using the 250 PSI Aquatec Pump, not the Surflow one. I would not trust my engine to a Surflow at any point. The Aquatec is what everyone is using because everyone has moved up to 200 PSI regulated micronozzles. I can a Setup on my Mazdaspeed and it let me make more power on the stock cat than anyone expected even without tuning. I used all Stainless Solid Lines and Swagelock fittings with a AEM Failsafe Gauge. The controller I used the DO progressive controlled worked great. The pump doesn't have enough load on it to warrant using more than a 10amp controller. Everything is handmade at DO, and I am skeptical to trust anything that could mess up an engine. If I do end up using it as secondary fueling, I would do a precompressor mix to make ti more vapor than atomized mist so it would be optimal to tune for. I prime my pump so it won't surge using solid tubing so it isn't a problem. If you mount everything with the right check valve, it is a non issue.

Those links have the same math bug I have been fighting for awhile now, the corrected Farad factor of the dielectric in the Supercaps. They don't act like cap, but act like batteries so the formula never matches up to what it is supposed to do. For example, if you have 3 caps in series at 3,000 farads each, it is actually 1000 farads total and does not work like amperage staying constant, yet the formula treats them like they are 1/3 the power captivity each. SO if you have a 2.5 volt battery at 1.2 amps and you put them in series you keep your 1.2 amps, but on that math, it treats it like you don't. The other problem is half those calculators don't say when you use Corrected Farads or when to use captivity of the capacitor's cell since they are assuming you aren't using them in series like a supercap bank. It is been really annoying trying to find out where the flaw in the formula was. After a notebook full of fact checking I did a test where I added a 2 amp load to the caps charged at exactly 12 volts, and the math said it would last 4 seconds less than it actually did taking into account the voltage drop. I tried to find the difference, but it was just not worth the day of fried brain cells to do so.


With the DC to DC converters, I would be using 6 to 10 of them and using them in a gated formula of a 1/6 duty cycle varying to a 1/2 duty cycle meaning the gates open for 10 out of 60 seconds in a round robin 1-2-3-4-5-6-7-8-9-10 section so that each gate opens for 1 second, charges a cap, then the DC to DC converts it, then moves to the next set. At full load it would increase the number running to 3 to 5 gated "sets" and have a maximum draw from the alternator of 1kw. Like I said I can't explain it without a diagram.

Also keep in mind the motor will be on a motor controller when running on the car, I just haven't forked out the money for one yet. The 72 volt ones are expensive.

Harlan

iTrader: (3)

Sureflo pumps are damn fine at what they do, and with the right diaphragms they handle W/M. I have the DO branded one and can't complain about the pump one bit.

Using all SS lines will prevent residual pressure in the lines which is good, but using PWM to control a pump will not give you linear progressive flow. Check it yourself a simple bench test with a measuring cup will tell you all you need to know about PWM on a pump. Very few things are handmade at DO, most are off the shelf parts re-branded, some are contracted out from china.

Surge is not about priming the pump. Surge is from hitting the pressure limit of the pump over and over again. For example it will be at 240psi and get that last squirt of water in then be at 270psi, then it will flow out the nozzle until 240psi again and then annother squirt of water to 270. The aqua-tech pump is going to have the same problem because of the internal pressure switch. Again, bench test. If you can see flow surging then your engine will see it too.


The AEM failsafe is a good idea, especially with the micro nozzle because they will clog.

I have no doubt you have used the same stuff to make lots of power before. You can make good power with a windshield washer pump and some mcmaster-carr nozzles. If you get the results you want then it's a win regardless, I'm just trying to share my experience.


The math on capacitors in series is 1/Total = 1/C1 +1/C2 +1/C3. It is no different for supercaps. If you have three 3000F capacitors in series then it is 1000F total. Just the nature of the beast. The actual energy stored adds straight across.

Just a guess, but to load test a circuit you need a resistor of some kind. A 2 amp motor will not draw 2 amps unloaded and also the amperage will not be constant as voltage changes.

1kw max alternator draw should be fine. Just expect that to be the bottleneck in your system. Run boosted for 20 seconds then recharge for a couple minutes.

Brettus

iTrader: (2)

I might be able to add something in regard to the W/I .
My setup gets to 16psi by 4500rpm and holds that to redline . I found 450 ccs of 75/25 W/M was at the limit of what the engine could digest without severe power loss . I now run 300ccs which starts around 12psi. and find no detectable power loss. I originally tried a pwm controller for a 2 stage setup but decided to bin that idea once i researched a bit more . Seems its a good idea to run a higher % W/M early on in the rev range which is what happens naturally if you keep flow constant.

As an aside : Cooling mist are ******* .
When my nozzle output didn't match the advertised output from their webpage I complained . I got an answer back that blew my mind ....." The rated output advertised was from when our pumps were running 150psi . Our latest pumps run at 200psi . "
They changed the pump psi YEARS ago yet left the nozzle outputs as is !
they then proceeded to ignore my request for a nozzle swap.
End rant.

badinfluence

Appreciate the feedback. Cooling mist looks to still be using the Shurflo pump Harlan is describing. The nozzle is the scary part. I went with DO's setup because of the microns on the nozzle. One thing I noticed is that those Aquatec pumps are legit. I was outside a very large yellow tractor manufacture because I worked for a parent company, and they were doing flow tests on them for a new kind of emissions standard. They copped the leads off and threw them away. For fun I took them home and they held exactly 200 PSI even after they had been beat on. One thing I did notice is that the fluid they ran was corrosive, so I never did use it on my methanol setup, but I used it to transfer fuel from a few carb bowls.

I was considering doing 50/50 or 25/75 Water/meth because it will get compressed inside the M90 and turn into a cooling vapor. If I insulate the intake tube it will operate like a air conditioner for the intake.

badinfluence

Yeah the Aquatec is much better about "bouncing off the pressure switch" than the Surflo version. The reason it does that is because it is designed for a higher flow, but reduced down a few sizes to increase the pressure without increasing the flow. I don't think the Aquatecs even have the pressure relief switch you are referring to. I have a tested setup from the Mazdaspeed 3 that I use for a few hobby like things. It still works great. I have never had it surge on my because of the check valve I used.

DO's stuff used to be made in China a few years back. That changed big time. The hose, and motor for the pump are still made in china like everything else, but the Nozzle isn't. That is the part that matters. I am not sure about the check valve, but I don't plan on using their's anyway. I plan on doubling the cracking pressure and going with one from Swagelock. Higher cracking pressure means less of a surge. I also had 20 feet of tubing, so the surge wasn't as much of an issue because enough pressure had to build to crack the check valve. I tested all this stuff extensively before I even put it on the car. I was being a ***** about putting it on my car before I did. I had about 5 months of happy trails on my car with that meth running in 100 degree Houston weather with a 70 degree intake. I logged every drive and made the failsafe log too.



That is the formula I did by hand, but it still doesn't add up. Either something is wrong with the specs of the caps, or the formula does not apply to supercaps. In one of the tests I did I used a perm motor from a old fuel pump. it was 2amps exactly. It had a blocking diode to prevent feedback. I get what your saying about math, but it just didn't add up, so I bought one to confirm that it didn't match. For instance the 350 Farad caps should not have enough energy to start the car 3 times, yet people test it, and even on Diesel starters it appears to work many times more than expected. Either they are more efficient than people are claiming the math is, or something is out of balance.

Harlan

iTrader: (3)

I think you missed one of my points. You can't test power draw with a motor. The free energy guys pull this scam all the time, they take a 2kw motor and then run it off a 12volt battery with a mystery circuit in between and say that they are producing 2kw for much longer than the battery could normally output. Just because it's a 2kw motor doesn't mean that whenever it's spinning it uses 2kw because an unloaded motor draws next to no current.

The same is true of starter motors, just because it's a 2kw starter that doesn't mean it's drawing exactly 2kw all the time when it's spinning.

The thing that is more efficient here is the motor not the capacitors and that's what's out of balance. If you want to get a clearer picture of current you have to use a shunt resistor and measure for yourself.