I just wanted to take a moment to thank the RX-7 Guru's and the people that created and moderate this great website forum. It is one of the best laid out and well run sites I have ever had the pleasure of seeing. The information on this site is increadible as well. With that being said, and considering I am a "new" RX-7 owner - a 1988 N/A (auto trani for the time being...), would any of the moderators and Guru's feel like tackling an interesting project? My company designs and builds and markets Tesla Bladeless Disk Turbine engines. These are quite probably the most efficient rotary engine ever designed. Nikola Tesla is the inventor of this amazing engine, and he patented it way back in 1911. Anyway - on to the reason for this post: up unitl now, we (International Turbine And Power, LLC) have never really seen a market for an automobile Supercharger. There are just way too many obsticles to overcome, and the cost of breaking into the market are very large. With my new "love" for the RX-7, and this forums potential interest in one...all I would need is some collaboration, interest, and help in designing a "super" Tesla-type, bladeless disk Supercharger for the RX-7 Wankel Rotary engine. This unit would be powered by an electric pancake DC motor, NOT driven from the engine (technically, not off a drive pulley system). I can supply just about any boost level that we would need. It would be a bullet-proof system, and the plumbing would have to be hand talored and built from scratch, but, it would be unobtrusive under the hood, possibly residing in the area now occupied by the air box. Any takers on some ideas from the RX-7 gods?! For review: http://www.frank.germano.com/index.htm (you can then view the associated webpages for further information on the turbine). Thanks, and I look forward to your replies.Frank.Germano.com

 

http://www.frank.germano.com/tesla_turbine.htm

As a Mensa, I have always been a fan of Tesla.
Interesting, but a little above the budget of most people. Rx7 owners seem to be on a tight budget and usually spend enough money on regular repairs, mods, fuel, and maintenance.

 

Fellow Mensa member here as well. The price would not be too high, and definately below conventional systems from Paxton and the like. If you are a fan of Tesla, then you must already be aware of the extreme simplicity of the Tesla turbine. Inside, there is simply a "diskpack" or rotor - flat, round disks with their centers cut out - the exhaust passages for the unit. All these disks are simply mounted on a shaft, with spacers between each disk. The only moving part is that central rotor. It has two modes of operation - when incoming fluid or gas is powering it - it's an engine. When an electric motor or other motive force is powering it, it becomes a "pump" which is capable of pumping any type of fuid, and, in our RX-7 Supercharger case, this would be pumping out a considerable amount of pressurized air - directly in the RX-7's intakes. Due to the incredible efficiency of the unit, it will out-perform just about anything else on the market - AND - we can keep costs way down in this instance, because - viola - I'm trying to do this for the "love" I've just found for the RX-7 in general. Look forward to some technical replies.

 

I think that a turbosupercharger application would be better. Rotary engines make their power at higher rpm's, and turbosuperchargers are more efficient. Also, the 2Gen RX-7 comes from the factory with a very marginal alternator, so the electric supercharger idea isn't going to work well without an upgraded alternator.

Unfortuantely, most of the Joe-public folks who buy go-fast car goodies are looking for "sight and sound" as opposed to actual performance. If I understand the Tesla turbine correctly, it is very lacking in both of these departments. Therefore, you will need to concentrate on your fellow Mensa buddies who seek higher performance gains. In order to compete with current turbosuperchargers, your product will need to exceed 76% efficiency @ 2.0 pressure ratio in the 35-45 lb/min flow rate range. Other desirable features are a fast spool-up and a steep compressor surge line.

BTW, does the Tesla turbine have dimpling to increase the Reynolds number, or would that make it less effective?

 

"Tesla Bladeless Disk Turbine engines"? There doesn't seem to be much of an efficiency problem with a (rather conventional) rotor-and-stator axial compressor, so why all this noise about Tesla this and Tesla that? The power to make boost still has to come from somewhere, and that somewhere is the combustion of gasoline in the RX-7's "prime mover".

 

If it were to be electricly drive would you have it only come on at WOT. or would you use controler to sence the RPM and reduce the speed of the compressor accordingly. If your claims about this are true, then we could very easily over power the requirments of the engine, thus detonating it.
Would it be better to adapt this to a standard compressor housing. or adapt the compressor housing to the disks.

 

I'm one of the more interested in performance than "noise" guys. And, if all that is needed is a electric power upgrade (doing this for increased power reason is more appealing to me than increased sterio system reasons) and if the otherwise cost isn't much different than, say, the Nelson Paxton kit, then there really might be something there.

My point is the most common complaint I hear of Turbo vs NA is reliability. Since this a more simple alternative, kind of address's the reliability issue.

My vote, keep the Forum brain trust available to this guy so this path can be explored further.

 

Thanks for the suggestion to keep the brain trust of the forum open. I have the technology to "create" whatever type of system we would need for the RX-7's rotary engine, and I can quite easily design the Tesla turbine/pump supercharger to fit in just about any boost/pressure/volume ideal that is needed, as well. There in lies the reason I posted this thread - I am not all that familiar with the Wankel ENGINE, as yet. I just bought the car because I wanted a "fun" project - well, on that note, I more than succeeded! From just a basic calculation, and what the prior member posted - we are dialing in from a base with about 92% efficiency...at 35-45 lb/min boost, and and (assuming the figure of 2.0 as an accurate psi - although that is very low to me), we are looking at a unit that would be approximately a 4 inch diskpack, and end up with five to six primary disks inside - this would then be a unit not much bigger than a McD's sandwhich box. Even at that small size, we can expect to pump about 10,000 cfm...again - if you give me specifics on what will WORK with the Wankel engine, I can quite easily design the unit. I'll test it out on my engine, and, if it's a "go"...I'll offer it through my company, exclusively to this forum at pretty much our cost. I've got some free engineering time on my hands, and this looks like a worthwhile project to have some fun with. Give me the hard figures, and I'll create the unit for you.

 

sounds pretty cool. Iv been looking to design to kit around a vortech supercharger. I need a system thats reliable. Basic questons would be what is the up time on one of these units. Do you even have a working model? The vortech model i was looking at is called the V-2 SQ. they say its good for around 680 hp. It flows 1000cfm with a maximum boost presure of 20psi. I guess if you had a pump that could do all that and was more efficent, that would be great.

I wonder how long it takes for your device to spool up and such. If it took a long time, we would have 'turbo lag' and when we changed gears and the rpm goes down the thing could have so much momentum that its going to make too much boost at to low of an rpm so a blow off valve would be needed.

Im intrested in this though. It be great to have a sponsor.

i would also like to see a working model. and i would like to see some reliable way to power it.

 

Sounds like a great idea! I have been searching for a supercharger that will be reliable and perform between 10-20 psi. I see conflicting posts about turbocharging and superchargeing all the time on the board here and on one hand I see the unreliability of the superchargers available with low boost and high cost and on the other hand I see turbo lag and so many moving parts in turbo 2 applications that something frequently goes wrong (hence the maintenance post up top). Couple these posts with the cost and time to convert an entire N/A engine over to a turbo engine and it makes me want to just stick with my 88 GTU N/A.

If you can make an easy maintenance high power supercharger that is electrically driven I am sure that you will turn some heads in the RX-7 community.

PS If you need some guinea pigs for this project I would love to enter my 88 GTU N/A as a part of the testing process!

 

So from what I gather from the last two posts, we are looking for appr. 1000 cfm, and about 10-20psi. Easy enough to do. The question about spool up time keeps cropping up - check out my website and familiarize yourselves with the Tesla turbine and pump. We have patented what we call a "CMP" and "CMT" (short for centrifugal molecular turbine/pump). These units (in pumping mode, which is what the Supercharger would be) have an instantaneous spool up time (or prime, in the proper sense) and the output will be for all practical purposes, instantaneous as well. See http://www.frank.germano.com/thecompany.htm (for specifics about ITP) and http://www.frank.germano.com/tesla_turbine.htm (for the history and theory behind the turbine and pump). What I will start on is a small bladeless disk unit with an adjustable boost pressure between 10-25psi @ 1200 CFM. This will be powered by a 1/8HP DC motor. I'll figure out an E-PROM program to give some tolerance to the adjustability factor varying with engine RPM and the like. Does Paxton or Vortec make a supercharger for the RX-7? IF so, I can clone their figures into this unit. Thanks again for the responses.

 

There was a paxton charger kit made some time ago, just do a search in google for supercharged rx-7. Even those some of the superchargers have a max output of 1000cfm @ 20 psi, we are not going to use that much. It just has that much potential. So we are going to need a fully adjustable control for it, It would be best if it is in car. I dont think it would be to hard to make a 'variable rpm switch' to send a signal to the supercharger control to control output vs. rpm.
if you need any ideas or help. ill try the best i can!

 

Thanks for the help. Basically, think of the bladeless disk pump as simply a super-efficient, self-priming, high output pump, in general. What Tesla did (and patented in 1911) was create the most simple, functional, zero mainenance unit ever designed. Like I stated in my first post - we looked at automobile applications in the past - it is just far too costly for us to enter into a market (i.e. superchargers) and make it profitable for us at this time. THIS project, I am eating all the cost of development and using my own "free" engineering time to come up with the design. All we're really doing is force feeding the Wankel with a larger supply of incoming air. All engines are - to simplify this - basically just large air pumps. What I have to figure out is how the Wankel reacts to input boost charges (of compressed air) and what the ideal amount is...heck, if it was a 350 Chevy, I'd be fine...I've only just begun to start working on the RX-7 Wankel, and I'm about half nuts as it is...!

 

Frank I love you......that article about the Tesla turbine is the most interesting article that I have read in years!!! This use of viscosity is totally mind-blowing!!!! I am SOOOOO in!!! I am broke as hell right now but I will do anything in my power to help you along and would like to be one of the first to apply this blower idea. I am going to get fired from my job here if I get any more distracted with this Tesla info LOL! .....work on architecture....must work.......on .......architecture...

BAH I should have been an engineer

 

I love then idea, but this will be for na cars? I don't know, can na cars hold that amount of pressure, or will we have to upgrade rotors, manifolds, and al that stuff, and obviously we will have to go foran upgraded fuel syste, maybe driveshaft, were looking at a basic turbo conversion here, so unless the price is REALLY good, i think a turbo conversion would be not better, but cheaper, and like deadRX7Conv said, most rex owners are working on kind of a low budget, so it all depends on price. If your looking for test cars, i have an 86 GXL. I'd be interested.

 

Very interesting. I see the most potential sales for a low cost basic model 1000 CFM @ 6 PSI, on-at-WOT model. On our N/A models, the driveline starts to break at loads much over 200 HP. Maybe leave the high cost, high boost, intercooler, fuel mods setups for the turbo guys.

 

Thanks to the posts from Capn' Wankel and MazdaRX7Racer for Life! Nice to see some interest here. To address some concerns: the PRICE of this unit will be so far BELOW current marketed Superchargers you are going to be suprised - ya see - International Turbine And Power, LLC (my company) already HAS the basic unit for this project. I do not need to modify our compressor/pump in any way. What I have to do is offer some type of CONTROL systems for it - or - well...that's when I hesitate. What I need are the following
1.) Boost Pressure required
2.) CFM required (normal and WOT)
3.) RPM range for when the Supercharger is "active"
4.)Compression Ratio
For now, I am building this to go on an N/A (hey...that's what I bought...that's what I have to work with - damn this automatic transmission, though. PITA)
Now...if you REALLY want to get ellaborate - the Tesla TURBINE can easily be retroed to be the most awsome TURBOCHARGER you ever saw. No bearing wear, no problems with temperature deterioration, and, quite honestly, in the space now occupied by the current Mazda RX-7 turbocharger, our unit could easily put out 3-4 times the available power/boost. Again - READ through the history of the turbine and pump and go over my website to see what we actual DO for a living. We have been at this a long time and are leading the industry into a new era of power generation. I'd drop the turbine into the RX-7 and go electric AC drive except for one small problem - INFRASTRUCTURE. The ideal would be for a small powerful engine (propane, methane or hydrogen powered) driving and AC Generator, running an AC Electric Motor...but...short of pulling up to a darn 7-Eleven...there is no infrastructure to support electric drive vehicles. Numerous advantages...no readily available supply, as yet. Give it time. We've got a 10-to-1 power to weight ratio. The Wankel is the most closely rated to that figure in the auto industry, and I think it's only around a 2.5/3.0 to 1 ration. Internal Cumbustion (conventional) are about the most in-efficient pieces of crap ever introduced to the market. But, hey...now I'm on a soap-box. Give me technical data, and I'll give you one lean, mean supercharger. Go further, and I'll build a turbocharger from hell for the RX-7. Thanks.

 

man frank your the coolest. i want one now would it bo good to use on a turbo say to make up for the turbo lag. also I think someone should get this stickied

 

Just one quick note to the RX-7 gods and moderators of this excellent website. I am not trying to take away from the RX-7 (engine or otherwise) in any way, shape or form. I am trying to now design a product, be it a turbocharger or supercharger (both are just as easy to design for the Wankel engine) and HELP everyone here that wants one - get one. AT MY COST. What I need are some technical data on exactly WHAT I need to design, performance and output wise. Before anyone attempts to ditz the idea, please read over the material on my site regardng Tesla, the turbine and pump, and my company. Go to http://www.frank.germano.com . From there, after entering the site, you will be greeted by a very thorough "index" page. Look up the information you require, read over it, try to understand the simplicity of the turbine and pump - and - then see how nicely it will apply to the RX-7 Wankel engine. Totally off the soapbox...

 

Do 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.

 

To TIIForever - again - NO TURBO LAG WHATSOEVER. A Tesla Turbine (and pump - for supercharger applications) SPOOLS UP INSTANTANEOUSLY. It will immediately supply boost. You have to remember (and why I repeatedly request you read the info on my site regarding the turbine and pump), that inside of a conventional turbo (charger) is just one, tiny little impellor. It's basically a fan blade in there. Same thing on the compressor side. One side compresses the incoming air (charge from your exhaust) and one side spits it back out to your engine (intercooler first). You have now created a more dense air charge at higher pressure for your engine to act on...okay...now -
With a Tesla type system, inside, there are several DISKS, not fan blades. These disks have an area of (remember your geometry everyone) of Pi X R X squared (can't get math symbols to work in this post, but you all know the formula for the area of a circle). That area is doubled because you have TWO sides to each disk...then...when you have lets say TEN disks in the "rotor" (the disk pack of the Tesla Turbine), look how much MORE active surface area you have to work with vs. a conventional turbocharger or supercharger. How does it "work"? By acting on adhesion and viscosity. The fluid or airflow wants to "stick" to the surface of the disks. It does (think of water flowing out of the bottom of a stainless steel sink...it "sticks" to the metal) - and - now the work is transmitted to the shaft - viola - either horsepower, or air movement.
Supercharger or TurboCharger...give me feedback, and I'll give you one or both.

 

Now the big question; will the pump be efficient enough to deliver 6 PSI @ 1000 CFM from ~600VA?

 

Interesting "post" thought: this sysem will work equally well as a dynamic Intercooler, as well. Agian, we are dealing with active surface area (what does an intercooler "do" - it cools off incoming air via convection through the plumbing, cooled off by air passing over the coils). We designed an "Air-To-Air" refrigeration system (called "FreshCool, patent pending) a while back. For intercooler replacement applications, the unit would probably end up being about the size of a standard lunch box. The hot air in would drive the Tesla diskpack, giving off its heat, cooling the air charge. The compressor side will further cool off the air charge...then it's back to your engine - all nice and cool. Give me feedback on this as well and I'll design a much better intercooler for the RX-7 as well.

 

SureShot,
Yes...I can design to those parameters. That's what I need - the technical info!

Frank

 

The reason I suggest 600VA is because it's similar to wiring up a starter.