Anyone know why Mazda never produced a supercharged rotary? It seems like it would have simplified the design, and perhaps produced the kind of torque they were looking for.

Long term plan to keep the RX7s on the road, and keep them fast could be a 7 with an RX8 revolution motor and some type of reliable forced induction... maybe a supercharger...

The 8 looks pretty cool. I checked one out at the Barcelona Motor Show a few weeks ago, but the 7 is a classic.

 

I thought you needed a camshaft to have a supercharger.....not sure if it would work with the location of the eccentric shaft.

 

Mazdaspeed version of the rx-8 might have a hydrolic supercharger. But I'd rather have a turbo due to the rotarys high rpm capabilities.

 

I agree ^

 

today's turbo's are alot quicker than when the FD was designed. A friend of mine had a Mitsubushi Lancer evo6 and i never noticed any turbolag.

 

well a superchager would still more torque away and well our jewel of an engine doesn't have that much to spare in N/A trim.

 

Turbos give way more hp anyways!

 

http://www.atkinsrotary.com/supercha.htm

yummy!!!!

 

they are belt driven so it is possible

 

dont see how the trick sequential setup can be compared to a blower but my guess is that a small light car like the 7 does not need instant torque that the blower would provide and it is really not a drag car

 

Superchargers rob torque to make power. Its the parasitic drag that makes the Supercharger only good for bigger higher torque motors like V-8's. Turbos still make more power, they are just more complicated and create things like HEAT that are the downsides.

 

I had a 1st gen with a ported 13b and a 9 inch blower and Nos. The car drove like a V-8. Watch what Mazda does with the RX-8 though.

 

Last time I checked, many s/c make lots of heat too. In my (very naive and uneducated) opinion, superchargers sound like a good idea for a rotary. They make less heat than turbos (especially twins), they provide more torque than they rob, and they're good throughout the rev range. Why do you say they rob torque? Ok, they rob some to spin, but have you looked at torque curves of before and after superchargers? They still produce a helluva lot more than they take up.

Sounds like a good idea to me...

 

superchargers run off a belt like Power Steering and Air Cond compressors. Except they have alot more drag than those accesories. A Turbo is Powered by Exhaust gas so its free power. It doesnt steal power to make power. The benfit is it makes much less Heat than a turbocharger especially at lower boost pressures and is always blowing even at idle. They work best on cars with alot more torque because they have it to spare. Sure it will make more power than a stock motor but not nearly as much as a Turbo. Thats why Small displacement engines like 4 cyl and rotaries respond better to turbocharging. Check out the performance figures on Supercharged Hondas VS Turbocharged Hondas. You will notice a huge gap. Its for the reasons stated above

 

I understand quite well the difference b/t superchargers and turbos, but thanks for the explanation.

I haven't seen any s/c and turbo graphs of small motors, but maybe I'll look into that. Evidently i didn't realize how much torque it took to spin the s/c, but now come to think of it I've never seen s/c on small engines. Good point.

 

Atkins Rotary info.....

We used a 390cfm holley for carburetion.


Ported & Polished Four Port 13B with Seven Inch Supercharger

Horsepower: 275 HP
Torque: 184 lb-ft.
Boost: 10 lbs.




Ported & Polished Six Port 13B with Seven Inch Supercharger

Horsepower: 276 HP
Torque: 178 lb-ft.
Boost: 9 lbs.




Ported & Polished Four Port 12A with Seven Inch Supercharger

Horsepower: 233 HP
Torque: 150 lb-ft.
Boost: 12 lbs.

 

The Rx-8 will be offered with a supercharger

Zoom is right and great info post btw...

 

Are these Crank or Wheel HP Figures?

 

The 7 inch blower is too small for the 13b. The 7 inch blower runs too hot and cannot supply enough air. If you buy a supercharger get the 9 inch if you can even find one. You should easily make 325 hp.

 

crank.

 

Hondas respond quit well to supercharging. The only real bad thing about a super charger is that the jackson unit can't be supercharged and because of this there inefficent at high rpms. Remember pressure = heat so if anything the supercharger will produce more heat in the intake at lower boost then a turbo. In a honda it figured about 10 hp is lost from the charger, so instead of making 230 hp its only making 210. Superchargers are made to produce torque off the line not take it away.
I've driven the same car that had both a supercharged and turbo on it and I really don't know why anyone would go supercharged. I admit the twin setup of the 7 sucks but I think its alot easier & cheaper to upgrade that then switch.

 

For 1 HP loss isnt a factor with drag. Torque is. Second i dont know what your trying to say about the jackson unit. The jackson racing unit is a supercharger. Hondas dont respond well to supercharging compared to turbocharging and your wrong. Supechargers dont create more heat than turbochargers at the same boost levels. This is a well known and documented fact.

 

I am in the process of trying to get one fitted. I have spoken to Atkins, but I you rather go with vortech SQ.

One thing is, those things are huge 9"x10". My concern is for space.

 

Depends on what type of Supercharger you are talking about, a positive displacement roots type, or a centrifical unit (Vortech Procharger). The roots type blowers are immediate boost, while the centrifical type will boost in direct proportion to RPM. Either type will have direct power robbing effects on the small or large engine, the only difference is that the small engine has less torque to begin with. A turbo will make a more dramatic improvement over the SC on small displacement engines, but the turbo is more complicated to install. Centrifical blowers also have a more linear boost curve, so it is much less of a hit to the car when boosting, as opposed to a turbo car's immediate 15 psi boost that makes the car fun but very hard to control under first boost.

 

Who has an opinion on the Mercedes 2.3 litre supercharged engine (the "Kompressor")? Ie. isn't it a small four cylinder engine?