I have a NA vert, and I had been under the impression that the drivetrain for the NA was weaker than for a turbo. Is this correct? should we be worried about making too much power with this charger? I love this idea, though.

I also have a 10 AE turbo, and I am interested in the idea of the intercooler. How would it work? Please put some more thought into the intercooler, as I am sure many, many, many turbo people would be interested in an efficient intercooler that does not require remodeling of the front end, or require spending 1000+ for a kit.

thanks for your work on this!
Kris

 

Frank, Thanx for your fast response...I can really dig the laptop hook-up...I have been building my own computers for the last 15 years. I saw some concern about how to control the output of the supercharger setup....I was thinking about using 2 "waste gate" type valves with the first gate going back to the intercooler input at a lower psi to "recycle" & suck out more heat while the second "waste gate" would dump excess pressure & de-power the supercharger by a time based percentage.
Here is the address for the peltier devices: http://www.tellurex.com/resource/spec.htm

Also, since we are talking about adding a major amount of electrical equipment & a heavy amperage draw, we are going to need to upgrade the electrical system. I live on a sailboat & have done more than my share of boat building & repair... so maybe a dual-output marine alternator/regulator setup would provide a high-tech solution. check out this link:
http://www.balmar.net/
these guys make killer stuff that is heavy duty & looks great too! But they are on the EXPENSIVE side.

The Balmar guys say its about 25amps/1HP draw.

The Peltier Devices give about 78watts of cooling power for 8 amps@16.1Volts. So - for 780Watts of cooling power U need 80 amps@16.1Volts - which will cost you about 3 HP at the alternator.

I had original designed a solid-state cooling unit for my own custom built computer rig & I immediately saw the potential for an active intercooler. I was gonna make one for my Harley & RX-7 as well.

I hope this is helpful & I'm glad to finally get it out of my brain after 3 years.

Ramses666

 

This sounds like a great idea and i plan on watching this thread closely. Because i may just be in the market, in the near future, for a product that will give my N/A some ***** .

I'm sorry i can't really help you out on the technical end of things because i am no engineer. But i would make a damn good tester, and i am in philly, so i'm not that far away hehe.

 

Using the following variables:
Height .030"
Outer radius 4"
Inner radius 1"
Volume 1.4137 cubic inches
disks 50?
Total Volume = 49 x 1.4137 = 69.27 cubic inches
1728 cubic inches = one cubic foot

Assuming 100% efficiency, that means about twenty five rpm per cfm, (1728 / 69.27 = 24.95) or twenty five thousand rpm for 1000 cfm @ atmospheric pressure, 50,000 rpm for 14.7 psi (2 x atmosphere).
For now, I will assume 50% efficiency, and that means 100,000 rpm.

1 cubic foot of air weighs 1.23 oz, therefore 1000 cf = 1230 oz = 76.875 lbs (atmospheric pressure @ sea level), or 153.75 lbs at 14.7 psi.

I just happen to have a 1/4 hp 12 volt electric motor at hand, and the data tag states 30 amps 600 rpm. I really can't see this motor turning a disk turbine compressor at 100,000 rpm and pushing 153.75 lbs of air per minute :-) My best guess is that in excess of three hundred amps would be required. I would suggest a belt drive.

IANE (I Am No Engineer) and would be greatly interested in the opinion of a professional engineer.

 

Well I guess that Camden Superchargers is out then. I was a bit confused because of so much talk about the blowers. I didn't know which one to pick for myself. I heard that Camden is going to have a recall sometime this year on all their blowers. I hope you are all not on their list.

 

I don't have the stats for the tesla disk....I also need to know how many cfm the engine consumes at 8000 rpm for a redline & the max recommended PSI for my fuel injected 13b. I guess I could try & figure it out but I'm sure someone out there already knows. I obviously don't have all the answers & wouldn't claim to even if I did. Thanx 4 the reply.

Ramses666

 

well, cant we just look at what the people with the turbos are running? If we could somehow find all the specs on their turbo, how much boost their getting, how much power, and what their turbos are rated for in cfm. I think that would be a good starting point. Also, with the supercharger i think he might be able to make it so the power isent 'Peaky' by making the boost increase at a linear rate.

It should be takin in account that the NA engines flow more then a stock turbo engine. Or thats what i hear at least.

Plan B would to get a charger with a lot of potential and run it really slow at first, then just keep turning it up untill optimal settings are found.

Plan C would be to find someone with all the answers.

 

80 cubic inch displacement (per one turn of output shaft) x 8000 rpm = 640,000 cubic inches or 370.370 cfm @ one atmosphere.
Double that for 14.7 lbs of boost :-)

As far as max psi on an NA, it would depend on the charge temp, timing, and a few other variables. But considering the stock compression ratio, I would guess maybe 6 psi would probably work.

 

Don't forget the fuel needed for forced induction.
If a stock ECU goes max 63% duty cycle .... this makes 167flywheel hp.
So everybody will need an Apex-I SAFC unit ->400$ US.

 

OK - So we are looking for about 750 cfm max all we need is what the motor requirements are for a tesla disk to move that much air...I found some high-tech neodymium turbofan motors for model jets & also some high power robot-war motors. I just need the torque specs for the tesla disk.

Ramses666

 

This is for a NA car.
A force inducted car has a higher brake specific fuel consumption

 

If U say so...I wouldn't know...I'm relatively new to the specifics of the Mazda rotary...which is why I'm here...I don't know the specifics & nuances of rotary "art"..I really don't even know what all of your abbreviations mean...

 

This is true. Seems the Syncro's stress tolerance is just with the demands of stock NA stress. My guess you'd be reliably good to, say, 225HP at the flywheel. But, it seems this alternative can be tailored to the use. For instance, this might be expecially excellent for a Vert with Automatic Transmission is your goal is just to improve the driveability of a daily driver.

But, retro-fitting a TII Tranny-back drivetrane is pretty much a bolt in exercise that can be done in a day and still stop for lunch.

 

Just so that we are on the same sheet of engineering paper, Pressure Ratio = P2/P1. Therefore, a 2.0 pressure ratio would equal 29.4psia in ISA conditions, which would relate to 14.7psig boost in layman's terms. This is the approximate boost level in which a stock 13B rotary engine block will operate somewhat reliably as a daily driver. Specially-prepared drag race engines will obviously handle much more boost.

Since you are new to rotary engines, you may want to check out RETed's web site:
http://fc3s-pro.com/main.html

I recommend that you post in the Single Turbo section to see what the drag racers would like in the area of forced induction.
https://www.rx7club.com/forum/forumd...?s=&forumid=23

 

sorry, not true ..... a fuel pressure regulator can do a rough job

 

Ok...so I think I understand why the confusion... the 2.0 figure was for atmospheres which you have translated into PSI.. ok got it ..thanx I am remembering my scuba classes...at 2 atmospheres we need double the volume of air to start with... if you take an upside down full glass of air underwater to a depth of 15 ft(2 atmosphere equivalent) the glass will be half full.

 

Wow... Very interesting stuff! How does this unit deal with the heat generated by such compression and inherent friction of the molecules while being moved in such a manner?

Count me in on it.. A supercharged variety that would nearly go unnoticed in the engine bay would be cool as hell. You could claim it was the second air box and still run massive injectors without anyone knowing any better. Major sleeper factor!

 

You keep saying that it would be too costly to market this. I strongly disagree. Look at the response fom just the members on this forum. just think, if you could make two mabey 3 "universal" superchargers. The "perfect supercharger". You make tree because you are going to need a slightly different setup for a car that uses more or less air. these are just the main part. Then you get into 10, 20, mabey even 30 kits that adapt the raw unit to a specific car.
This is why engineers aren't any good at business.
There are millions of car guys and galls out there looking for the very thing you cay you can make.

Lets say the Company puts in 1 million dollars to develope this. then afer the testing and everything is made. it costs the company about $1000 to make a complete kit that will bolt onto a specific vehicle. you sell them for a little less than your less efficint counterparts and your have just made millions!
chew on that.
I take it though that you haven't been a car guy very long? When I say car guy, I mean you can look at and old rusted out POS wiht no motor or tranny and say, "What a great car" and instantly have a vision that contantly evolves into this perfect ride, you ride.
I will explain why I ask if you want me too.

 

Like I said before: Keep it simple (like a 50 shot of nitrous): On at WOT, off at anything else. If this thing is practical, and costs less than nitrous, the NA guys will swarm on it. (That includes the 4-bangers)

 

I would go with a 6 PSI @ 1000 CFM production size. Here is why:
1) Will work with stock ECU & fuel delivery by only adding a cutout on the FPR.
2) No intercooler needed.
3) Short, intermittant use is within the capability of the stock battery & alternator.
4) The larger displacement guys can add a 2nd battery and pair them up.

 

I don't know if this will help or not but Eaton Automotive has several graphs showing the CFM, power, and temps vs. the superchargers speed made by there positive displacement superchargers. it might help give you an idea of what the compitition is doing when it comes to there blowers. I was looking at their M112 model, it's the biggest one they make and they only show output at 5 or 10 psi.

http://www.automotive.eaton.com/prod...rchargers.html

 

You know some of us dont drag race. i road race, and im looking for a system thats going to act like a normal supercharger. Its true, what you say is simple. But i wont be able to use that one bit! I want to make as much power as possable too. Fine, ill put a whole TII driveline in, not a problem with me! same goes with the fuel system. If a good unit is made, it could work both ways. You have have 2 different control units for it.
also, who would want to but another battery in their car?

 

It sounds like there are two different types of applications people want this for.
One side wants a cheaper nitrous replacement the otherside wants a cheaper turbo replacement.

 

Ok...I checked out the Eaton Supercharger Temperature data. It seems to show an increased temp(delta T) of 88 degF with the Temp maxing out at almost 200 degrees F when U increase pressure from 5 psi to 10 psi - pretty much a straight line increase with the rpm range of their supercharger. I can see how you are gonna have a problem with out someway of getting rid of that heat with the Temp maxing out at almost 200 degrees because its gonna detonate your motor if the psi start pumping up there. So if we want to get more than 5 psi of boost we are looking at a significant temperature rise problem...

So if we are talking about the active intercooler - The Max delta T for the Peltier devices is like 78 degreesC. I tried to do a conversion & came up with a Max Delta T in degrees F of 174.2. This Max Delta T is the theoretical capability of the device - the actual application Delta T is somewhere around half that.. so something like 88 degrees F!! So now I need to calculate how many watts does it take to cool 750 cf of air by 88 degrees F. From my analysis of the graphs for the peltier devices this application seems to fall within the "sweetspot" of application criteria for these devices. I gotta go for now...I'll get back on this later...

Ramses666

 

Hello Frank and ALL the wonderful RX7 lovers,

I just got mine a few weeks ago and I'm in love, This one of favorite cars, previous 71 challenger, 300 benz, alfa r., sunbird se 3.1L, but by far this is favorite. I'm no supertech when it comes to the RX7 yet, but if a supercharger at economic price is developed I'll be the first to line up......Thank for you positive energy and support of our love for the Rotory motor. Looking forward to see what developes.....

BLVD43