Has anyone super charged a 13B leaving the fuel injection system

what brand of super charger is recommended

 

should i be an *** and just say...

Google

 

http://www.camdensuperchargers.com/
http://pbgarrott.tripod.com/Garrott.html
http://www.mazdarotaryclub.com/forum...ad.php?t=26201

 

If you like noise and don't mind spending $3,000 for only 176hp: Camden

If you autocross and don't mind hunting down a kit that is no longer in production and correcting a few minor engineering flaws for about 210rwhp: Nelson/Paxton

If you want more power than a bone stock FD RX-7 then go with a turbosupercharger.

 

You are probably going to get a whole bunch of people that will come on and say use a turbo as it's better or don't waste your time or some other response like that. The fact of that matter is that yes it can be done and doing it on a rotary is no different than doing it to another type of engine. A turbo is not always better but then again neither is a supercharger. Everything has it's pros and cons. The only supercharger kits that were ever available for rotaries were substandard attempts at it which is pretty much why the rotary community is so against it. They've never seen a nicely done one and most people lack the capacity to pull it off themselves. Those that can do it will typically opt out for easier and cheaper options to the same goal. The few brave souls that have tried it on their own and have shown off their work have only succeeded in fabricating bastardized creations that even the worst back woods mechanic wouldn't touch so there are lots of things going against the image of the supercharger on the rotary engine.

If you are curious about it then hopefully you've done some homework to know the pros and cons of it vs other options. Everything has them so once you learn about the different types of superchargers, then you need to decide what you want out of it. Even if you find a setup that will meet your needs, then you need to see if it is worth the money or the effort to pull it off. This is usually what deters most from doing it. Turbo systems have been around on rotaries forever and applying them to rotaries is common knowledge. A supercharger isn't so easy though. You'll be on your own sizing it as well as building the kit to install it. It will also cost alot more money and in the end you will probably have gone just as fast with less effort and money spent by using the standard turbo. That doesn't mean that no one should do it though. It all depends on what they want.

If you want to attempt it, learn how to read compressor maps. They still apply for superchargers too but there is more to sizing than just a map so do some homework. Then figure out what it is going to take to install it. Figure out where you want to put it and how you want it all to fit in. It isn't rocket science but it will take some effort.

 

I will have to do some more research

I guess because of the lack of supercharger use or market for the 13B is why I am unable to find out a lot of information but thanks for the input

 

See Corky Bell's "Supercharged!" book. It is inexpensive and written for average people.
http://www.amazon.com/Supercharged-T.../dp/0837601681

 

Is there likley hood of overboosting a rotary engine with a superchager?

or is it out of the question

I only intend to make my car a drivable street car with a little more get up and go but Like I said I have to do more research

Thanks again

 

The build guidance in the below link would also pretty much apply to belt-driven superchargers with reference to boost pressure. However, some supercharger types have poor thermal efficiency and/or do not lend themselves well to intercooling, so you would need to adjust for the extra heat or use anti-detonant injection to stay within the knock limits vs. a turbocharger producing the same boost level. The Corky Bell book will explain the different aspects of the three most common types of superchargers.
http://www.fc3spro.com/TECH/FM2W/power.htm

If you are simply looking for a cheap and easy way to add more power, then see the 2nd Gen section on this website for instructions on a TII engine swap or adding a turbo to your non-turbo 13B engine. Belt-driven superchargers are for those who really want them, and are willing to pay extra money and spend extra time to install them.

 

I would say there is a much lesser chance of over-boosting a rotary with a supercharger than there is with a turbo, since a turbo relies on load and exhaust volume, and regulates boost by introducing a hole to re-direct exhaust flow, whereas a supercharger is almost entirely RPM-based. As long as you do your research, properly size the compressor, and calculate your gearing - i.e. know your compressor wheel RPM for a given engine RPM - you should be good to go.

-Disclaimer, I have never built a supercharged rotary engine, however I considered it at one point.

 

The supercharger is more likely to cause damage from over boosting. If you change pulleys to increase boost a couple things happen.
1) Immediate boost, I mean "immediate". This is nice, provides great torque however if you are not tuned right and your timing comes in too early you can easily pop an apex seal (done that)

2) Boost increase=intake heat increase, you need to run methanol injection to compensate. This intake charge increase can lead to additional engine stress and/or detonation (snapped off a bridge on my half bridgey)

3) The roots charger will fight when going much above 10 psi and the wimpy 6 rip belt will tend to slip. This is a design which helps prevent damage to the drive mechanism in the charger. To compensate: liberal use of belt dressing.

I am a camden user, I support the use of the camden for the right purpose. True it is an old outdated design, but I do compliment camden for producing it for such a small market. Considering they only sell 10+ per year to a declining market anyone can understand the reluctance to invest more money in making improvements. Truth be told, Dave Atkins likely never recouped his entire investment in this venture through the profits from such limited sales.

Also, yep a turbo will provide much more peak hp dollar per dollar. The Camden has it's limits, once you reach them that's it. With a turbo you can start small, even cheap with a TII s4 stock turbo and invest in the engine. Then later upgrade exhaust, then turbo, injectors, etc etc. You could start at 170 rwhp and year by year upgrade gradually to 350+.

To travel back in time, I would rather do a small block v8 transplant or a TII transplant. Back when I made the leap our dollar was weak and I jumped based on the rumors of how well the camden worked. I also based my decision on trusting the engine that I had in my car. Unfortunately my motor lasted "1 day", so the camden and new motor ended up costing huge $$$$$ and I had no choice but to stay committed.

That was 6 years ago. After experimenting extensively, popping 3 engines from stressing the limits and breaking one supercharger I know all the limits. I feel my engine/blower combination is at it's peak and hope to dyno before the fall to see where I have progressed to.

Future
1) Build my holley 750 hp carb which will have 800 cfm potential

2) try out my $500 ebay 5 inch camden blower that I finished going trough to compare against the 7"

3) nitrous, although I am really tempted to try this out on my spare $200 "donor" motor to test the limits. Really want to spray a 100 shot at a full tune with my biggest carb and an open header. But, that has to wait.

4) already have a sweet T04r, will accumulate the rest to go turbo one day and feel the rush of 340+hp of boost.

Recent upgrades:
1) streetport exhaust (aka roadrace), huge improvement!

2) pulley change to increase boost (I have 5 different pulleys on hand)

3) 4.88 gears, awesome launch!

 

I am also debating a large streetport or half-bridge on a supercharged s5 6 port...

 

been there done that

 

and your advice is... if i go half bridge i want to turn 10k+ rpms

 

There's a Camden kit you can buy for your FC

http://www.atkinsrotary.com/quicktim...ntro-video.mov

 

welcome to the new century turbos are the Godzilla of the planet. Especially with the new turbo technology with variable vane turbos they are just like having supercharged boost instantly. super charging is out of date and a wast of time in every way u look at it. EVEN ON EVERY OTHER ENGINE yea dragsters still use them and funny cars but those guys are just old schoool and scared. as street cars do 6 second ET's these days BY USING TURBO's lol

 

lol is right.
Have you ever driven a supercharged car? The throttle response is instantaneous, and the power is perfectly linear. For a road course, I'd rather not have my turbocharger kick in while I'm in the middle of a long high-speed off-camber sweeper.

My FD is a little bit faster, but my blown Miata was much more predictable, flickable, and dare I say fun(?) on the track...And the sound of a centrifugal supercharger at full howl...that's a whole 'nother story.

 

I don't really agree with you here, I'm not sure how much experience you have with turbo cars, but when boost starts to increase, it does so very quickly. The same situation could go with changing the spring in a wastegate to increase boost, if you are not tuned right, it will start climbing very quickly, and as wastegate springs are not always 100% accurate and boost can be hard to predict, you can do damage. (done that)

Not to mention you don't have the predictability of a drive system. In a supercharged engine, Engine RPM x gearing = compressor RPM, no?. In a turbocharged engine, it is completely load dependent. Change your downpipe? Your boost will increase. Any change in your engine's breathing will affect your compressor RPM and boost pressure.

This doesn't even include mechanical failures on a turbocharged engine, like wastegate lines ripping or coming loose. Nearly any failure of any sort on the WG circuit will result in over-boosting, unlike a supercharger where I imagine any failure would result in under-boosting.

I'd say superchargers' boost is much more predictable than a turbocharger, and as such risk of over-boosting is less.

As for the heat from compressing air, when you look at centrifugal superchargers they have the same problems and "fixes" as turbochargers, i.e. Intercoolers / AI.

 

well good luck let us know how those hp numbers are the mileage your getting

 

I've built some Eaton units just to see how it would work out. Imo, if all you're after is a modest ~50-80 hp bump in power than they work great. For Eaton blowers on a 13B, this is a MP90 of the the older technology, or TVS 1320 of the newer 4 lobe design. (I think the newer 4 lobe design would work well for adding more than 80 hp)

As for overboosting...it's pretty simple - know the Ve of your engine vs. the pulley ratio between eccentric shaft and sc pulley. Then go with a ratio you calculate to only supply like ~2 psi to start. Literally at ~30% throttle you can look at the boost gauge and see the positive pressure already on tap before you even floor it. Your target boost will fluctuate +/- 1 psi dependent on the SC Ve and the Engine Ve.

If your goals are realistic, you won't be disappointed.