I have a '91 RX7 with a stock FI 13B NA engine. I use it as a daily driver, and weekend drag racer.

This is an everlasting debate. I voted turbo simply because the parts are more readily available to turbo our cars. Which is better...well thats just an opinion and should be left up to the owner...

supercharger is probly going to be more reliable than turbo... but i guess it really depends on where you want your power at. with turbo youll have a little bit of turbo lag, wich i guess these days you realy odnt have to worry about anymore... with a supercharger your pretty much getting instant power... theres more to that, and both have thier pros/cons... but we need to know more about your whole set-up

IMO I like Turbo's powerband better, I likw the swift kick in the ass feel. Plus for the most part you can always make more boost, but not on an 6 port engine. So.....Its more a personal preference.

why not on a 6 port engine? i was thinking about leaving my 6port, getting it ported and the rotors beveled and turbo-ing it withought the whole t2 swap...

Please elaborate on this one... I'm assuming you mean put lower compression rotors in?

A turbo is like adding free horsepower. You are using wasted exhaust gasses to produce more power. With a supercharger you are taking power away from the engine to make power. So say if you boost 6psi with a turbo and 6 psi with a supercharger with all else being equal, the turbocharged car will make more power to the wheels.

twin screw supercharger(only supercharger worth its salt)= good throttle response and early boost all the way to redline ~ 340hp pin you in your seat corner exit, more fun imo. oh yeah, you can fmic this supercharger! this supercharger will take to higher boost better than the roots.



centirfugal supercharger= same as the single, just belt driven... probably the only benifit is cost.



big single= huge boost, more power, too peaky for having fun with around town and in the mountians.

good for drag and hwy racing.

Superchargers create massive power all the way through the powerband. Thats the only reason I like them.



I would take a turbocharger before a supercharger just because its cheaper and easier to do. But if you have the time and money, a good supercharger setup will outrun a comparable turbo setup. Unless you do that crazy electric assist turbo charger, then it will be about the same.

i think he's talking about the CLR rotors.

have you seen them? i actually didn't know about them until last night when i was reading thru the other forum.

they look like this:

https://img.photobucket.com/albums/v...y/HOrotors.jpg

wow why are they like that

Not totally. Power is required to spin a turbo. The turbo creates resistance against the exhaust flow and therefore, slightly more energy is required from the pistons/rotors to expel that exhaust. Granted it's not much, but it is there. The benefit that a turbo has over a SC where parasitic drag is concerned is that drag increases with revs on th SCed engine, where with a turbo, drag lessens or stays similar as revs increase.

More info on those rotors!! lol... what is the benefit, where is their site?

thats the cnc machined lightened rotors from racing beat....





in my machining experience, to just to run a mill around on a face of a rotor -- its way overpriced.



benificial? yup, you bet.



price? sucks the fat one.

Thats what the RX-8 rotors are built like. It has that beveled edge for the side exhaust ports.

Those CLR rotors are lightend, and beveled. The lightening, of course is to improve response, it's easier to spin rotors that weigh less. And the Beveling on teh side of the rotor is to get some more timing out of the ports with out porting them, it also helps the motor to flow a little more because the air moving from the ports doesn't have to make such a sharp transition into the chamber.



As far as SC over Turbo, I don't really have any prefrence, especially since I have never seen a SCed RX7. Just pic a power level, and build the motor accordingly. And if you use a SC, I would only use a Twin Screw. Maybe a 6-71 blower, that would be neat.

And if you want to check out the work involed in a custom SC install, check out some posts by 88IntegraLS he put a twin screw in his NA.

Well, I vote for supercharger, obviously because I have one on my car! https://www.nopistons.com/forums/pub...IR#>/smile.png



The instant boost outweighs a turbo's fun factor any day in the city driving...



http://media.putfile.com/New-Camden-Supercharger

I say S/c, bc I want insant power I dont want to have to wait on it.

Uh, they aren't Racing Beat, as said before they are CLR rotors.



And I vote turbo simply due to the fact I'm one broke mofo, and can do a complete turbo conversion for under 400 bucks.

No I wasnt saying no tto boost a 6 port, I said you cant crank the boost like you can a 4 port, well its not like you cant, but 4 ports were designed for boost. You know what I ******* mean......

I hate the sound of superchargers. Other than that, I like both of them!



But I'm still a turbo man at heart. https://www.nopistons.com/forums/pub...IR#>/smile.png

Turbo for the simple fact that it would be cheaper and easier to do, because it doesn't sound like you have the budget.



Plan on spending $2500 on turboing the N/A motor or Turbo engine swap. You may not need all that money, but its nice to have some extra padding incase you need to get new tools and such.

Id like to slap a supercharger on my vert for the more linear throttle response and instant power, but considering how hot rotary's run, its kind of a shame to waste all that excess heat flowing straight out the back, especially when compared to a piston engine. Wouldnt the SC install be easier tho, cause only the intake would need to be re-routed, and the SC mounting location wouldnt be as tricky to get all the tubing to?

Even though SC's are more reliable and give instant power,



Nothing gives me a rush like boost in the powerband.

isn't there one of these every other month or something like that. As they all say. Its up to you and your wallet.

Correct me if I am wrong, but doenst a s/c make boost too?

NOT IN THIS REALITY

Won't those beveled rotors lower the compression greatly?

I don't prefer one over the other but i voted S/C because I will be ordering a Camden when the money comes around. There are alot of turbo 7's in my area so I thought I'd go the other route and see how it works out.

In general I consider superchargers to be better for low end torque, while turbochargers are better suited for high rpm horsepower.



I chose turbocharger since we are talking rotaries though. Rotaries in particular seem to go well with turbochargers since it capitalizes on the high exhaust energy that rotaries have.

The only supercharger I would consider putting on any rotary would be a centrifugal type. They would be easy to fabricate a bracket for and are as easy to intercool as a turbo is. They do have a little bit of lag like turbos do because they essentially are a turbo that is spun by a belt rather than exhaust gas.

I think that Maria Motorsports used to sell a centrifugal type supercharger setup (wonder why they stopped?).

I've always been told that on a 6/7/8000hp top fuel car, the s/c takes over 1000hp to drive. Talk about parasidic drag wowzers!

question. How many companies acauly make these things for rotaries? i meen, with stock turbo cars you generally dont see very many for good reason. Stock S5 13b's generally dont have that much turbo lag, compared to other cars of the era like the toyota supra, so i dont see much of a point fabbing up some s/c setup when you could just get a decent setup on what was stock a turbo

theres also the fact of noise



NA's are ******* loud.

on TII's the turbo acts as a muffler pretty much, so it quiets things down.

Yeah it seems it's nearly a waste not to turbo a rotary, way too much energy in the exhaust - some of the 20b's posted here have turbos that look like they're nearly as wide as the engines they're on.

So your saying that when i turbo my na im going to lose one of the things that i like the most about my car.

That great loud high revved sound....hmm maybe ill look into super chargers then.

the turbo acts as a muffler.



with the exact same exhasut on a na and a turbo, the turbo will be a little quieter. but im not saying all turbo cars are quiet.

you're taking the energy that would go out the exhaust as noise and using it to spin the turbo https://www.nopistons.com/forums/pub...#>/biggrin.gif

Who is still making supercharger kits like Nelson used to have for the FC?



Would like to doe something like that for the vert. and when time comes to smog. just take it out. That's the only + thing I like about sc and the instant torque so i can make a heavy car take off the line a little better.