Jeff,

I would love 3 rotor power too but keep in mind you only considered half of the picture. Along with the weights you mentioned the eccentric shaft, gearbox, driveshaft, clutch, and rear axle assembly may have to be beefier to handle the increased torque. Add to this a larger water pump, probably larger fuel tank, larger radiator, larger cooling fans, larger oil pump, larger oil sump and the increased volume of oil, water and gas. Now the icing on the cake may be larger tires and brake rotors and heavier suspension components to handle the extra power/torque/mass. The candle on top of the cake will be a heavier structure (body in white) so the vehicle can still pass crash tests because there is more dead mass/inertial energy for the structure to absorb.

Even if the aftermarket can make a 3 rotor and not add all of the above does not mean Mazda can get away with it. The aftermarket cares little or none about safety factors when offering components. Mazda has to. Think about it: you put a turbo on an 8 and then if the tranny blows 5% of the time it is not the turbo kit makers fault. If Mazda had a 5% tranny failure rate they would go the way of the dodo.

I think when it is all said and done we are looking at adding 200 lbs of pork. Undoubtedly the car will be faster and less nimble. There are plenty of hyper-powerful sedans available. I prefer Mazda makes a nimble sedan (yes, I said sedan).

Of course, after my diatribe it occurred to me that Mazda may have designed the RX-8 to handle 240 ft-lbs from day one. If this is so either give me 3 rotor now or get rid of the extra 100 lbs added to the car to handle the 3 rotor.

 

Except with the FD, the RX-7 engines always gained more power through the years. 1988 - 146hp, 1989 - 160hp. I'm thinking along those lines that a more powerful NA motor will come along after a while. And hopefully such engine advancements will bring the renesis at least in earshot of the 300hp mark.

 

I'm with you Red Devil, just keep it normally aspirated and I'll be OK.

 

yes, basically as technologies improve which would allow for lighter rotors, seals, and stronger eccentric shafts, we'll see an upward move in the redline, and with optimalization for more upper RPM torque, this 2 rotor NA could go well up to 300 bhp...
('cause that's why you see that 10 hp gain over the life of the FC)

 

I just read the post on the turbo, and I must say I much prefer the idea of a 3 rotor motor to turbocharging the current Renesis. 3 Rotors will as discussed add a little weight, but this can easily be offset by placing the battery in the back and/or other mods. The tradeoff is probably worth it, don't you think?
Also, the motor can be made to give more performance than the Renesis but allows for more relaxed highway cruising and maybe even better mileage.

 

Geeze you guys give it a chance... I'm sure the engineers put allot of thought into this car. They didn't take anything lightly I am sure. Being the fastest car on the road has disadvantages... especially in the insurance area.... more HP means higher insurance... take it the way it is and modify it if you want more... that way you don't have to pay higher rates.

Mazda needs this to be an affordable sports car if it's going to pay for it's production line. That's why you see so many Mustang V6's on the road... without the V6 model the couldn't keep the line open for the 8 cyl version.

A nice sports car for 26,000 needs to have a little more markup from the factory to pay for it's production line... otherwise they'd need to make a 4 cyl version that you would see everywhere like the Mustang. If they made an expensive 350HP version it wouldn't sell well enough, they'd have to produce a cash cow in the same body..... I don't know about you, but I don't want to see "stripped-down" RX's all over the place. Keep it unique.. keep the cost down so they can sell just a LITTLE more of them than needing to sell droves of them to make money.

If I wanted a $40,000 car I'd be looking at something else anyway.

There is more to this car than power and cost to produce it... there is economics involved as well as making it attractive to a specific market.

 

There is this rumour out there that an FD w/ a 20B loses all of its handling. I invite anyone to come on down and take a ride in my 20B powered FD and tell me that it can't handle anymore! The only problem that I have now is when I am blasting though the 10-20 mph switch back curves in the Texas Hill country, is that I can no longer stand full on the throttle exiting the curve! Unless I turn the boost down to about 6-7 psi. I just went and drove about 270 miles in the rain with a local car club and my car handled just as well as it did when I would blast through the same areas when it was 13B powered!

 

I would love to see a Renesis version of the 3 rotor! But I would rather see it non-turbo in a "new, if they ever build it, RX-7". It would cost a whole lot less not having all that excessive weight from the Twin-Sequential turbo manifold and snake-hose nightmare to run it! And nothing revs so smooth as a nice 3 rotor motor!

 

We should all just give thanks to the powers that be for even letting a rotary engine grace our shores once again! The RX-8 is a great place to start!. Just my opinion of course.

 

A MR 3 rotor RX-7 is all I ask. :D

I think that is the ideal location for the extra weight if it is going to be added. Without need for a back seat, or even a rear trunk, a MR RX-7 based on the RX-8 platform might even weigh less with a three rotor motor.

 

rxman720b,

Just out of curiosity, like Wakeech said, did you have to cut the driveshaft and move the transmission back? Also, what's your gas mileage like?

I saw a 20B in a shop once right before it was installed, but I never got the details of how it went. I did hear it's a difficult conversion, then again, I've seen a 350 small block Chevy in a FC.

 

i don't know if this was mentioned or not i can't seem to find a post leading to it but is there a rotor to piston ratio such as 1 rotor =3 pistons or v6

 

Just look at the power output for 2 rotors.. it's pretty equal to a V6 or I6, but with a much nicer torque curve

 

It's actually about the same as the BMW I6 engines.

http://www.e46fanatics.com/faq/m54engine.html

Hard to say it's much nicer realtive to these examples. :p

 

meh, that's not so bad... for a top-flight, most-advanced-in-the-world piston engine... i guess... :p

heh heh

 

First I want to ask since the rotor always fire in the same place in a rotary engine I was wondering if you cut a Center housing in half and then made it thick enough to use the stationary gear and a 20B eccentic shaft. You would then have a 3 Rotor Renesis engine and make lots of power and would be able to do it for a lower price. I don't think mazda will make a 3 rotor. But I would love for them to do so. I think that the next Rx-7 should be a 3 Rotor Renesis engine N/A. so it would pass emissions and make more torque. I could still rev to 7000 or 8000 rpm. what do you guys think.

 

hey all u buddies r forgetting about speed!!!!



i mean i like the 2 rotor and all but i LOVE speed!!!!
Dont any of u guys enjoy going fast??? come on!!! wak up has anyone seen the new 350z? 3.5 LITERS OF DISPLACEMENT THAT IS LIKE A HUGE TRUCK MOTOR WITH MORE POTENTIAL THAN THE JZE-GTE IN THE SUPRA AND GS300,400 AND IS300 i sorta wanna acruallty win some races?



and for that we need power so i WANT the 3 rotor although if they dont make a 3 rotor u can also get a cosmo 3 rotor off of http://www.rotaryengine.com/ although i think i really would be unhappy not to have a renesis version of the 20b.

than again a 4 rotor woud be phenominal.... stick a big turbo on that and the power would be god like...

huh... too bad u guys dont like going fast.

jk

 

Wakeesh, shutup already with those FD's. I swear, if this man had to choose between sex with one hundred women, or a mint condition 91 FD, he'd take the FD. ^_^

 

It's not the quantity, but the QUALITY.

The FD stands firm in the quality area

 

A 91 FD would be a rare find

 

ahahahahaa!! well, you see potatoes, i've had the equivalent of 100 ordinary women (take a gander at the pics i got of my ex, in my photogallery: link in my sig), and well, i'm lookin' for more than that now... and you're thinkin' '93 FD, my friend. hee hee hee!!

 

I always call the 2nd gen the FD. Let's just make the 2nd gen the FD now, so that way I'm always right.

 

I hate to bust everyone's 3 rotor dreams, but according to rotary news the rx7 will have a 2 rotor motor with increased rotor size. Something like 90mm.

 

the rx7 should have all the turbos and the 3 or 4 rotors , leave thr rx8 alone

 

*sigh*