I was just wondering, do u think that it will be possible to put the new RX-8 rotary into our 1st gen rx-7s like u can with other 13bs? Can u imagine how great that would go!!!

 

Yeah about half as fast as my 500bhp 13B Turbo !

Go buy GT3 and get good at playing it, the rx8 is about 2 to 3 sec a lap slower than the rx7 RZ spec, feels low in power in the lower revs and is poorly geared for it's power band.

In std form it is very ordinary.

The data on the GT3 game is VERY realistic and has been confirmed by REAL test drivers to be within 2/10th's of a second of real cars performances in std tune trim.

I for one am not that "thrilled" by the RX8 engine, it may be more efficient, but it needs ALOT more broader power and more of it.

 

you Fu@king kidding arnt you???

 

It'd be sweet if they last aslong as a NA 12A. 250hp + reliability + cleaner, now were talking

 

Was that GT3 thing a joke? They're going on 2+ year old data on a car that's not even finalized yet. C'mon buddy, step back into the real world. Didnt you read the article R&T had about GT3 and how realistic it is a few months ago? The game NSX type zero was something like 40mph faster than the REAL one on the same track. A renesis in a 1st gen would be killer... it's obviously not a 400hp hopped up 13BT, but it'll be a hell of alot more reliable. And how about a turbo on a Renesis huh? hmm...

 

WEll, you are not going to find a used Rx-8 block for sometime! I would say that even when you find one, I hope you are going to get all the nessessary hardware with the engine to make it work. or get a Haltech.

 

I'll put a T2 motor into my 1st gen, when the Renesis crate motors come out, I'll put one into a 3rd gen with a blown motor

 

THAT would be my idea of a perfect car .

 

i would want the tranny, 6 speed closer ratio

 

I beg to differ son.

I make 13B street port motors with 9.7:1 comp, and they make 250+bhp at lower revs with alot more mid range power than the RENISIS is able to make.

With the 11:1+ compression that the RENISIS has you could make a lot more power, which is what I intend to do when I get my hands on some rotors and see if they can be used (if possible).

All the crap about fitting in double the size exhaust port and bigger intake is fantastic, but this is what we do when I street port an engine + the benifit is that it does not recycle exhaust gases like the RENISIS !

THE THEORY OF RENISIS IS FUNDAMENTALLY FLAWED !!

For real power you need overlap and not to recirculate wasted gases from the exhaust cycle.

THE ONLY BENIFIT OF THE RENISIS, IT IS CHEAP TO MAKE (FOR Mazda compared to turbo) AND THAT IT WILL USE LESS FUEL, BUT WITH THIS IT MAKES LESS POWER COMPARED TO A SIDE PORT WITH PERIPHERAL EXHAUT EVEN THOUGH IT HAS MUCH MORE COMPRESSION AND HIGHER REVS !!!!!!

Do not get me wrong here, it is cool that the rotary is and will be more main stream and insure it's exsitance into the future, but I will stick with the proven theory of Dr Wankel & NSU & NASA....the real power of the rotary is in overlap and the benifits it offers in Volumetric Efficiency.

Give me the compression of the RENISIS engine and I will guarantee you ALOT more power and be just as reliable (I do not have reliabilty issues with my 500BHP turbo engine "daily driver" only tire durability issues !), may not pass the worlds strongest emmisions tests though

OH & forget turbo charging unless you can only live with 5 to 6 psi boost MAXIMUM due to the high compression.

 

This conversation is very interesting i am kinda new to the rotory world but i am glad to see people with such great minds working on thsi board.

jr

 

This is the first time I've seen the word "overlap" on this forum. I don't quite follow what you mean, because we have no valves/cams in our engines. Please expand on this - what "overlap" means in a rotary engine, what can be done to increase overlap, and what the pros and cons are of doing that in a street-driven RX-7. Thanks!

 

"Overlap" in a rotory refers to the time the rotor face "sees" both ports.

Ryan

 

Exactly right.

Here is a graphic of the benifits of overlap, studied by John Deer (Liscence taken over from Curtis Wright, now expired) On the benifits of over lap as it pertains to the amount of air the engine breaths.

 

What kinda porting can you do to an engine that has side exhaust ports (RENESIS)? I'd rather it be a peripheral. A quiet rotary is going to be odd.

 

Well when I get one, I will be bridge porting the intake at minimum...the exhaust side will not take this at all as the bridge will suffer from thermal fatigue very quick.

If I can retro fit 3rd gen rotor housings I will, but again I am not sure of the parts compatability.

If all else fails, it will be easy to peripherl the exhaust like we do the intake now days via fitting in a sleeve arangment....I have a PP Turbo engine with Experimental Aluminium Exhaust sleeves TIG welded into the spot of the normal stailess sleeve (to get exact port exit dia I want) and it is holding up to 850BHP worthof heat so I guess that the 400 odd I want form the RENISIS will not be a problem.

There are many ways to skin a cat ! ....I just have not caught this one (RENISIS) yet !

 

Bridged intake with a PP exhaust plus 11:1 compression would be major fun...

 

Plus direct injection ! (Thanks Magnetti Marelli)

Mercedes Benz did this in the 70's but via Mechanical Injection.

I have alredy planned my next project

 

Did someone just call me "son"?

Hey Dad, it's "RENESIS"... get it right.

 

That's been my gut feeling.... it made no sense to me that one could make MORE power with ZERO overlap. I knew the peripheral exhaust ports were a big problem for emissions, though... which has got to be the only reason why Mazda went with side exhaust ports.

I didn't know about the higher compression in the Renesis! That's one thing that I've wished for ever since I first started learning Rotaries... "If they have such turbulent combustion chambers why not run sky-high compression?" High C/R = higher efficiency, lower exhaust temps... and the engine can make super high ratios work on pump fuel.

Man, that would be sweet if Renesis rotors would work in an old peripheral-exhaust 13B... it just might be enough for me to give up my 12A obsession.

 

Just keep in mind, if you looked at some of the techical issues with this engine such as a 3stage intake system. This will allow better lowend flow characteristics were rotaries have trouble with. This will make the power curve more broad and usible. I don't think Mazda is trying to make a racers engine like we are, but just trying to keep it semi-sporty. Having the right length and diameter intake runners at various rpm is a major jump in this engine system they are using. You'll probably be able to do some porting to this renesis engine too when you get your hands on one. Maybe a bridgeported exhaust! LOL That would be funny since we never been able to do that before. I am sure though, mazda engineers made it difficult to modify it since thats there job. They probably left very little material in the intake track and exhuast track for porting purposes.

I am curious about this 11:1 compression, I don't know what they did to the rotor's dish face, I think even if they elimated that dish, the max ratio wouldn't be that high. I thought if they didn't have that dish there, their is a issue with even combustion in the chamber. Also, I'm curious if they may have changed on apex seals since they no longer ever come in contact with port holes and red line is beyond 8500rpm. Are steel ones still used?

 

If there was no dish the comp would be over 16:1, I cannot remember the exact figure (I calculated it out one day !)

But yeah this is one reason why it cannot run in conventional form as a Diesel casue you cannot make the compression any higher with a single stage rotary.

 

Crap, misread.