i think its time someone did it. it seems like a pretty nice upgrade for the NA peoples, hp goes from 160-230?

 

I remember someone with a black gp kitted fc did it. I'll search for the thread now. He was super pleased with it iirc.

 

https://www.rx7club.com/2nd-generati...-hi-uk-884483/

 

Don't see a tonne of reasons to do this swap, isn't a turbo II engine more capable?

 

^read that thread. Ton of drama over that very subject haha

 

yeah, but if you wanna stay NA the Rx8 motor is a good option

 

Renesis FC would be my 2nd choice build after my S5 NA FB.

Been scheming on it quite a bit. I would probably take an S5 TII chassis for the host.

 

there was a dude in japan swappign them into SAs & such. I would love to do this in a daily! "reliability" (i think they're good if it's one of us owning it lol) of an RX-8 in a lighter, better looking body

 

since when were the renesis engines reliable?

they're about as reliable as the REW engine, the upside is the power is more linear. it would sure be a kick in the *** over the FC n/a engine but with more power the reliability takes a dive.

you would need to retain most everything on the engine to actually make the same power due to the rather complex intake system. (read as the thousand times i harped on people for removing emissions on their n/a's) you can't just toss an EMS onto it unless you have an EMS that can control the various actuators and at the proper RPM and load points.

sure it's doable but i would only say it's worth it if you got a wrecked RX8 with nothing to put the engine into.

 

I think they'd be plenty reliable if someone who's very knowledgeable about rotaries already, which a lot of the older more experienced users her are. I mean,if they can last for 40k or more w/ some high school girl owning it, they can totally do 100k w/ a purist, enthusiast like me, you, or any other person on here being the owner/operator. Right? Or am I crazy lol

 

Landon303 >_> You don't want to know...

 

they actually seem to do better with the high school girl than the "knowledgeable" rotary owner.

actually its just like every other rotary, it lasts 6-8 years, mileage is irrelevant

 

well if you visit the RX8 club with the mentality of a 7 owner they will boo and hiss you right out of there.

the renesis does have some more involved inherent problems than the older cars, you definitely do not want to flood out one. even a kill switch would hardly help you in that event to get the car quickly started back up. i have nearly burned out starters just deflooding them in the past.

the early engines had lubrication issues, leading towards burnt side seals and excessive rotor housing wear.

add in regular coil swaps(the ignition coils have been known to fail on 18k mile cars, yes that is right..) and the chunk more expensive plugs and you will find that EMS/intake/exhaust to be a bit more appealing than spending hours swapping in the newer engine.

most early owners have been through at least 1 engine before they even clicked over 100k miles. this is partly why i suspect mazda threw in the towel on the rotary engine for the time being. just when i think my 8 is fine it cranks erratically, sounding like it doesn't want to start and the idle drops like it wants to stall out. it has 81k on it by the way, early RX7 engines never gave me these troubles.

yes the renesis makes a bit more power from the start, but not much more than you could get from the earlier engines. the renesis also does not move forward very well with modifications in making more power than you will get from it when you drive it off the dealer lot. the engine does rev more freely and get out of the hole a bit quicker than the lower compression 7 counterparts but peak power limits are still the same.

in essence i feel i could build up an early engine to do a similar job and actually be MORE reliable. the only real benefit is the renesis intake system, giving it good all around power.

 

Totally! Though not having a Renesis I speak only from what i've heard from others - folks like you.

I'd like to learn a little more about the Renesis intake system. Do you have any diagrams or videos illustrating it? is it that much better than the S5 VDI?

Honestly the thing that interests me most about the Renesis is the side exhaust ports, and elimination of the overlap of intake/exhaust cycles. It seems that change alone should allow for significant power over the S5 platform, plus higher compression.

I guess there's not much room for porting the Renesis out with the side plates they use? Is it a water jacket issue like in the older 6 ports?

 

even with the side ports there is overlap between intake and exhaust, always will be with this engine design unless you incorporated an actual valve system to close each charge off from one another.

maybe the future will be a rotary with intake and exhaust valves.

i haven't seen any diagrams of the renesis intake system, it is similar to the S5 but also has a third air velocity runner.

 

true. i could go on but i wont.

the deciding factor with the Rx8 for me, was that my friends who have them, off forum, have NO TROUBLE with them. it does seem like reading the Rx8 forum = engine failure.

the 8's do have problems, but its not as bad as the FD.

 

in concept the Rx8 intake is like the S5. the runners have more gradual bends, and they are sized for each port better. there are a couple of SAE papers, if you want PM me.

i think the power limit is the exhaust port, and you can't port it enough to do anything. so more power is not realistic.

although i do know of a japanese shop that spent 6 months going between the flowbench and the dyno, and they make like 280rwhp. they offer it as a package from air filter to exhaust tip, for $16k!

 

Curious! I'd love to study the differences in S5 / Renesis. And - more info on that 280whp build plz.

IMO the S5 VDI intake is one of the sexiest intakes I've seen. It's like they studied two gorgeous naked women making out and then translated that to an intake manifold.

I think we should adopt this methodology into all aspects of RX tuning.

 

Weird, I want the opposite. A RX-8 with a NA REW engine (on S5 NA rotors)!

Somebody already makes the engine mounts, if only somebody made an intake adapter, where the stock RX8 intake manifold would bolt in to the REW block

 

i think Knightsports has an REW with Rx8 intake in their time attack car

 

Rx8Club ... pssh ... don't get me started! it's a curious lot over there; something like the bliss of ignorance mixed with the stink of arrogance. don't get me wrong, there are quite a few people that know their **** and have it together, but there's even a few of them that lack foundation. of course, this is all my opinion (based on the time i spend over there), but i feel somewhat justified when i see some of the prominent members there noting the same things.

the Rx-8 and the Renesis ... ahhh yes ... another pair of curious subjects to me. how does the company that brought us from the crude days of 6 mm carbons and twin distributors up to the 20B-REW take a bold step forward and a few timid steps backward (at the same time) with the 13B-MSP? how does a car that handles as well as the Rx-8, remain such a joy to drive yet somehow wondering what the hell was Ford ... er, i mean Mazda ... thinking?

overall, i agree with just about everything you said. a lot of it truly balck and white and really cannot be successfully argued. however, the last statement leaves me a bit of two minds. it's not the part about being able to build an older engine to close-to-Renesis spec. it's the MORE reliable part and it's only because i strongly believe that with a few changes here and there (internal and external parts), the Renesis could be made very reliable.

 

tell me about it, i have never had to use the ignore feature on this site but i have a few people on ignore over there. with higher resale value tends to come more arrogance. even a few in the 3rd gen section here get under my skin.

problem with the renesis is partly the control system, it is overthinking its job in order to save the catalyst. the engines just run erratically at times and it is not mainly because the engines are in poor condition, it is because the ECU is telling it to do something it doesn't want to.

the flooding problem is what bothers me most, they fuel wash very easily and without yanking the rather difficult plugs out it is extremely difficult to air out the side port block.

 

as much as i bitch and moan about my Rx-8, i do love it. it was never love at first sight, but it has definitely seduced me in the 6 years i've had it. however, the little things that fail on this car (and the engine) are inexcusable! if the FDs are truly less reliable (overall), then all i have to say is WOW.

 

the FD is a complex nightmare of wires and vacuum lines, but honestly i don't see all that many issues with them. the small things are just much much more apparent, like a failing boost solenoid causing erratic boost. but it's a little unfair of a comparison from a twin turbo 20 year old car to a 8 year old non turbo.

an RX8 with a solid check engine light, i scoff at it and keep driving because it is out the next time i jump in. if it's flashing and running like *** i know there is a real problem. it just isn't a rotary car if it isn't trying to make you pull your hair out.

granted the most reliable car i have EVER owned is my '87 TII, once i yanked everything out of the engine bay and put the bare block with turbo back in there. simple is best and it's just too bad mazda has to work around emissions, which is the root of all evil with these cars.

 

yeah, they used to bother me, too. this was the FIRST Internet forum i ever joined, so it was a bit of a shock. that said, i've become a member of several car forums over the years and with the likes of people on the Audi forums, Porsche forums, Lotus forums and even the Supra forums, i have to say the FD and Rx-8 crowds don't seem that bad.

yes, the ECU is one of the top most vexing things about the car. it has way too much involvement in just about everything! i have experienced the erratic running, the occasionally sketchy throttle response and a few other weird actions that make up the Rx-8 experience. i HAVE NOT (knock on wood) experienced the flooding with mine though and that's even with me tempting fate every so often when i move it out the garage to the driveway. nevertheless, i see your point if i ever do have to de-flood it. it would be a nightmare. by the way ... i'm just going to throw this out there ... was an oil pressure gauge really THAT expensive?


i'm somewhat (second party) familiar with the FD's infamous vacuum lines, solenoids and such. however, i never owned one, nor do i have any "real" friends with one, so i'll take yours and J9fd3s' word on the subject. it doesn't deter me from wanting one someday though and given my experience with the 8, i tend to think i'm quite prepared.

yeah, the coils got me once so far. i have the occasional check engine light, but it's issues with my oxygen sensor that i assume come from the fact that i no longer have a functional catal;yst (a la ignition coils). then there is the occasional tire pressure light (i think it's because i made the mistake of getting 35-series tires) ... joy! finally, the damn thing insists that the passenger rear door is open at all times, so i have to endure the open door light. did i mention dashboard lights drive me insane?

your comment on simple is best rings true. aesthetics and nostalgia aside, the Gen I Rx-7 is by far the best rotary car they made as far as i'm concerned and SIMPLICITY is the reason why i believe that to be true. don't get me wrong, i have enjoyed the strides in technology on paper, and even some in practice, but when it comes time to working on let's say a Gen II, i'm still learning and in the time it takes for me to sort through some of those issues, i could have literally built a Gen I from the ground up. maybe it's my own inadequacy, but that's how i feel.

that said, i have always wanted to own (or at least drive) a JC Cosmo just for the sake of doing so and from what i've gathered, there is nothing simple about them.