Big_Will

Hey Everybody,

I read on some website (it had a real generic name like rx7.com) about a guy who was waiting to put Renesis rotors into his FD to make more power. Will this actually work? How about renesis rotors into the other generations of motors?

How much of the cool Renesis stuff can be transplanted onto the older rotaries (twin throttle bodies, hardened internal gear for 10,000 rpm redline, etc)?

Will the Renesis make a good engine swap engine? I know electronics control the twin throttle bodies and stuff like that, but assuming you could get all the parts out of an RX-8 (as soon as some idiot crashes his brand new one) or from the Mazda dealership, well most of it just bolt right up?

From what I understand, the block overall should still be the same. The main differences on the new Renesis involve moving the exhaust ports to the side of the rotor housing and the intake ports are now on the other side of the engine. Based on the info from the aforementioned website, it appears that the rotors are redesigned to be a lot lighter though they are the same shape. So will having different manifolds bolting up to the new port locations effect the engine mount locations? I'm just wondering if a Renesis swap is a practical idea or not.

Thanks.

Will

neo_omega

Won't know until someone really do it.

peejay

All Renesis thinking right now is conjecture because nobody has any actual specs or engine parts in their hands. Gotta wait like the rest of us...

Jeff20B

iTrader: (13)

What if Mazda used 13A specs in the Renesis? That would almost gaurantee no interchangeability with the 13B.

lenny

from what i heard, the renesis is smaller than the 13b-rew. im not sure if that is just because of the removed turbos, or if the engine itself is smaller. but I think it would be pretty cool to put one in an FD if it just bolts up.

boostmotorsport

What are the odds of it just bolting up... slim I think

jbontke

I would think that most of the parts would be interchangeable. The redesigened housings and rotors might be different, but the front cover wouldn't change for reasons of saving money by raiding the Mazda parts bin. And the rear plate wouldn't be changed because of redesigining a bell housing and transmission selection. They would have to make transmissions specifically for the RX8. That would be a big waste of money when they could rob the RX7 parts bin for its transmission selections. It would be neat to take the paddle shif from the RX8 and put it in you FD. Kinda have that Modena feel.

peejay

They already do have to make transmissions specifically for the RX-8...

If any of the internal dimensions are changed, my thinking is that they'd make the "diameter" smaller and the rotors wider, the engines seem to get more efficient thermally as the rotors get wider, because you get more volume for minimal surface gain. If they made the eccentricity/trochoid dimensions smaller and then widened the rotors to make the same displacement, they would get a better surface/volume ratio, as well as lighter rotors, lower seal sliding speeds, lower internal shaking forces, SO MANY gains.

Even if everything is the same internally as the 13B, I still doubt it would work well because they had to have changed the way the corner seal/side seals fit in. They moved the intake opening point further advanced than what is possible with current rotors. They might still be useable in a side/periph 13B but you most likely wouldn't be able to make a bridge worthwhile because the bridge would have to be so close to the rotor housing that the eyebrow would be quite small, unless you made it big enough to interfere with the water seals.

Again, everything at this point is conjecture, and I'm basing all of these thoughts on what little information we do know, and present them with the full understanding that I might be flat-out wrong.

yayarx7

Is the renesis not a dry sump system. I thought I read that somewhere. That would make the front cover have to be different because of the lack of an oil pan. wouldn't it?

krazyjl

but your decreasing the "leverarm" of the chamber - so torque will go down, but revs go up. which seems evident in the renesis

peejay

Think about it.

Sure you'd be decreasing the leverage however you'd have more width on the rotor pushing on it. It's a zero-sum equation - basically torque is related directly to displacement, regardless of leverage in the engine.

glenn

The internal dimensions are exactly the same. How do I know this? Because I've seen some renesis rotor housings. They look exactly the same as 13b housings but without the exhaust port.

I know of two workshops here in Australia who have had these housings for some time. Unforunatley they dont have any centre or end plates though.

These housings were bought in with some import 13b motors and are apparently mazda test parts.

RETed

I find it hard to believe Mazda would somehow "missplace" prototype engine parts that really haven't been released for public consumption...



-Ted

glenn

Why did I know I would get that kind of response?

I can tell you that I have seen these housings with my own eyes. Adelaide Jap Dismantlers aquired them with some import motors and they were later sold to Dalton Automotive. I personally know these two companies very well and I myself was very surprised to see the housings.

Ted , I know it maybe hard to belive but these housings do exist. I am not in the habit of publishing bullshit posts!

Glenn

RETed

You have only 3 posts in here - 2 are in this thread.&nbsp Go figure...


-Ted

glenn

Ted, what difference does it make how many posts I have published? I am simply stating that from what I have seen the internal dimensions of the rotor housings are the same as a normal 13B.

Glenn

13bpower

When is the Rx-8 supposed to hit us soil? The first model year will be 2003 if Im not mistaken. Wouldn't that mean about september 2002? Anyone know for sure?

peejay

By US law for a car to be sold as a 2003 model, it can be sold no earlier than Jan 1 2002.

Ford did that to us with the '97 F-150, sold starting Jan 1996, and sold alongside the (previous-gen) '96 F-150. Bastards

85RX7GS

iTrader: (1)

Should see it sometime early next year if not later this year...hopefully

im4u

the rotors would fit.they r 14% lighter so this causes the lower torque plus the higher compression i believe.i was thinkin bout this swap also.plus i believe it is recieving a 6 speed tranny.when i thought about the electronic controlled t. bodies,why not replace them with like 2 ford t.bodies and us two throttle cables,it would just be a great big mess for the person that would do ur ecu wiring

peejay

That's ome of the more "interesting" theories that I've ever heard. Hmm, heavier rotors=more torque and lower compression.

RETed

Gimme some of that crack you're smoking!


-Ted

im4u

no torque equals twisting force correct?if they are lighter than wouldnt it cause less torque?i wasnt sayin the lighter they are causes high compression i said the high compression of the rotary keeps the torque down but the rpms up

peejay

uh.........

I don't even know where to BEGIN...

Torque is no relation to rotating mass. Torque is entirely from the combustion process.

Higher compression ratio increases torque at all RPM.

RETed

You're getting all confused, or you just went through a shitload of literature on lighten flywheels...

F=ma, but in this case we can rearrange things around a bit to F/M=a.
Force/Mass = Acceleration
Force is directly related to combustion.
Mass is obviously the mass of the rotor itself.
Acceleration is directly related to torque.
To INCREASE Acceleration, we need to either INCREASE Force (combustion) AND/OR DECREASE Mass.
It's all there in black&white - this is physics.


-Ted