Christopher

I thought I read somewhere about a 250kw (335hp) rotary engine for a future faster RX-8, can anyone confirm this? I was thinking that if this is true then Mazda could use the 184kw (246hp) standard RX-8 engine in the next RX-7 which I assume will be cheaper than the RX-8.
By the way a great little Forum!

Jeff20B

I'd like to see a 20B in it, or whatever the 3 rotor Renesis will be called (if there ever is one). However, a turbo is the most likely way Mazda will substantially increase the power of the (standard 2 rotor) Renesis. A jump of nearly 100HP could be accomplished with serious porting, but it would get away from the whole 'zero overlap' the Renesis is known for, and increase emissions.

BlueAdept

Why turbocharge the thing for an extra hundred HP, with all the reliability problems that brings when you could just add a 3rd rotor and have an additional 100HP for almost no extra complexity and probably no more weight than a turbo and intercooler units.

wakeech

true, but then you run into size and cost issues...
whatever the case, i heard about a report in a post a while ago about development of a 2.0L RENESIS, but i dunno... it doesn't seem like the kind of engine for the 8... or even the 7. Most of the guys on the board were more interested in the reincarnation of the "rotary pickup" whatever-it-was-called...

but, to get back to the origional thought, that's a helluva lot of power for a smallish sports-sedan, with an "affordable" (at least for many [not most though] of you Americans) price tag of $30 000...
it'd just be way too expensive, and it'd scare away potential buyers, i think (it'd be one hairy beast in bad weather, on top of higher inherent costs associated with higher performance)...

BlueAdept

I'd like to point out at this point that I'm not american... LOL.

Driving on the correct side of the road, I wonder if we'll get the car before the US too... since they can just retro-fit the Jap model??

Mabe, but I've got my flame retardant undies on now anyway... ;-)

red_base 95

You know asbestos causes chafing:D

For those that want a high performance sportscar with a lot of power, the RX-8 is not the car for you. I think most of those really interested in this car (including myself) are willing to compromise some performance for utility and affordability. The 8 I'm sure can be driven hard, and be a delight to drive everyday.

250 hp in a car that weighs less than 3000lbs (2970 I think) is more than adequate to provide the thrills most of us want. Depending on how the insurance companies classify this car (coupe, sedan, sportscar) will make a big difference in cost of ownership. And while the power rating of the engine doesn't claddify a vehicle, it will make it more expensive to insure as it increases.

RX-pecting

questions, really.

I don't know if this has been discussed, but, what is 13B (I assume 13 is for 1.3 displacement)?
What is the "zero overlap"?
Why is this 50:50 weight distribution so important?

hope I don't sound too clueless...

wakeech

no way man!! don't worry about it, only a couple of months ago, i hadn't the foggiest about the rotary, and nary a year and a half ago, the my only automotive intrest was F1, but has blossomed of late...

anyhoo, to answer your q's RX-pecting:
the 13B everyone talks about was the last design of Mazda's Wankels; the "13" was for the 1.3L displacement, and the "B" denotes it was the second major design concept, which leads me into your second question...
i don't know (anything) about the A series motors, but in the B series, the inpiration ports are through the side rotor housings, and the expiration port is through the peripheral rotor housing (where the apex travels around...). Also, in the later model (but mayeb the S4's as well?? not sure...) 13B NA's (where the technology REALLY was, not the turbos) there is also a 6-port inpiration system, which has two extra (but smaller) secondary ports above the "main" secondary ports in the intermediate rotor housing. These extra ports would open and close (so the inspiration cycle timing was different: the port would be open for longer -> same as increasing valve lift and duration in a piston engine) with a cylindrical "rotating" valve, which was actuated using exhaust pressure (which could be screwed up with an aftermarket, low back-pressure exhaust, but that's another story) to open at a certain range of RPM.
SO, after all that, the thing that the RENESIS has over the 13B is that it has true "zero overlap" which the guys mean to say "zero timing overlap" between the inspiration and expiration cycles. The RENESIS has side expiration ports, rather than a peripheral one, so they may be located closer together (just better timing all together), larger in area (means better breathing, like a well-ported 13B out-of-the-box), and there is zero overlap between the cycles, cutting on emissions.

the 50:50 front/back weight ratio is "important" because it will mean the car has close to equal normal force on all four tyres (assuming that side to side is balanced as well), which means that there shouldn't be an uneven distribution of grip about the car; this makes the car easier to control and predict, giving the driver greater confidence and leeway when driving spiritedly. It doesn't manufacture grip, or magically cause the car to go quicker through a corner: it's just easier to drive, and because of that balance will corner straight and easily.

wakeech

oops!! was gonna link this, forgot...

http://www.rotaryengineillustrated.com

it's taught me much of what i know, and all that i've forgotten...

B-Nez

Speaking of insurance, back in May my wife called our insurance company, and they actually had a quote for the RX-8. We are married, over 25, no accidents or tickets, in FL, and they quoted us about $450/6 mos. Not too bad all. Our '98 Wrangler 4-banger had been running us about $350/6 mos. The CSR went on to say that it was a good thing we weren't getting the new Z, because the insurance for that is going to be astronomical. I have no problem trading 30 hp or so for the difference in insurance premiums.

wakeech

hey that's pretty cool!! i wonder what the insurance'd be for me (but i'm in Canada) for a 19 year old kid... not like i can afford it!! (i'm just a rotor head...)

BlueAdept

Have a bit more respect for yourself...

You shouldn't be describing yourself as a "kid"... (at least in the UK that term would be reserved for the younger child... say under 15/16)

I can't tell people how to live their life, god knows mine isn't perfect.... but take charge, if you REALLY want somthing... go get it. Sure you can't get an RX-8 tomorrow... but in a few years who knows, you might have been able to save some.

I sure can't afford one now, but I'm sure as hell gonna have one.. (assuming everything is as it seems)..... I might not get one for the first 6 months or a year, but that might be good, let them work out the bugs!

RX-pecting

BlueAdept is right, Wakeech

Don't put yourself down like that! I myself am 21, and there's no way I could ever buy the car by myself. But, saving up, you could make a substantial down payment on it (mayB w/ help from family) that'd make the payments more friendly. Plus, don't forget, my Canuk collaborate, us folks up here's gonna get lower range prices, ay!

Chin up Wakeech :D your car is in sight!

wakeech

huh?? putting myself down?? it's just who i am!! i just don't take stuff seriously, and i just wanna have a good time...
it's not that i mind not being able to buy the car!! whoa whoa whoa!! i'm saving for a second gen (post '88) 7, but that's still a ways off...
and btw, i am just a kid!!:D i couldn't live any other way!!

thnx anyways though, guys...

ekrampitzjr

To make the story brief, Mazda's original production engines were the 10A and 12A. The 10A died after 1973 in all markets, but the 12A remained available until the mid-1980s in RX-7s. I believe that the engine may still be available for industrial use, as versions powered by natural gas were being used for refrigeration applications some years ago. The 10A and 12A used the same basic rotor geometry, roughly speaking, with the main difference being the rotor width.

There was a 13A. It had totally different geometry and was offered only in one car, the extremely rare R130/Luce of the early 1970s. Fewer than 1,000 were built. The car was primarily sold in Japan, but a very few made it to locations such as Australia (not officially). This was Mazda's only front-drive rotary car, and the engine was optimized for this application.

The 13B, based on the 10A/12A geometry, followed right after the 13A, but Mazda had to use the "B" suffix since there already was a 13A. Hope this clears things up. I can't really add much else to the excellent discussion of "zero overlap" and 50/50 weight distribution above.

BlueAdept

Did I understand it correctly that the Renesis is a developed 13B (13B-XXXX) where XXXX is a revision I can't remember?

I'm sure I saw that somwhere... RENESIS is just a marketing name.

SureShot

So far I'm really impressed with the Renesis. The side exhaust ports should have been done years ago.
Renesis is to Mazda what Northstar is to Caddy.

boowana

This site keeps getting better and better. There are many very interesting posts. i too am new to rotary engines, but thanks to a lot of you, am learning quicky.:p

BlueAdept

I'm learning quickly... the problem is that I'm learning that I want one of these cars... and I can't have one...

RXRX

i know! all this talk about the rx-8 makes me want it even more..

zoom44

i know what you mean.
my kingdom for an ounce of new info on the rx-8!
an ounce doesn't sound like much but its a very little kingdom.:D

wakeech

hey blue adept, that evolution you were thinking of was the side expiration ports, which allow the intake and exhaust cycles to be much closer together without any overlap, improving nearly every characteristic of the engine...

also, i think the whole thing is some kind of aluminum alloy, rather than the aluminum alloy / iron alloy (some kind of steel), multi-layerd sandwich... that's where i think all the weight savings has come from (just speculation, but it was a huge percentage over the 13B-REW, which couldn't just be from elimination fo the turbo system...)

Christopher

I agree totally, but I was just wondering if anyone had heard of a more powerful RX-8 coming out, maybe for racing? or is the 184kw (246hp) the only version coming out at this stage?

wakeech

um, not sure... someone mentioned something about a detuned version which'd be cheaper... but no, there won't be a more powerful model, 'cause then there'd be no place to push the RENESIS (whilst keeping it NA... which i think Mazda wants to do to keep the engine affordable) for the RX-7, something around 280 HP...

boowana

I got a quote from my State Farm Agent here in Dallas. Based on a cost of $30K, my premium would go up by $78.00 per sisx months over my '99 Miata. The toal would be $516.00 per six months. That's clean record, drive to work, major liability coverage, etc. Not bad!!!

If the final cost is $35K (estimate loaded to the gills) my premium would go up by $114.52 every six months over the Miata. Still, quite acceptable