i'v been thinking. out main problem for the rotaries is this... n/a they are marvelous and completly reliable (to what i hear and read from ya'll) our turbo motors:
1- rotaries strive massive power off of turbo's and increased boost.
2- our engines life span DUMPS dramtically down the hole as boost increases
and get quicker and quicker prone to detonation, (all motors do) but
more so then piston engines (correct me if i'm wrong.)

how could we gain horsepower / reliability together???

instead of rebuilding so much our cuurent tired turbo motors... would it not be a better idea to get a 13b-evolv (correct if wrong on id for rx8 motor) and give it a slight massage and surpass the emmisions and hp of a stock 13b-rew? rx8 N/a has 240-255 whatever the ectual is. we have 255 twin turbo... i imagine it shoudl bolt almost perfectly in, be lighter, better emmisions for us. and being n/a much much more reliable for over 100K! granted new motor version costs money. a good rebuilt REW costs 3-5K how i magine a brand new RX8 motor would be 4-5K power FC should be able to control the motor. we'd get rid of the whole sequential giant nest fo vacuum lines for the turbo's (simpler engine bay).
i imagine we'd lose a bit if not quite a bit of torque... but for the reliability it's be worth ti don't you think? or is my whole concept or thought somethign of the dark ages. i'm just wondering for ourselves since we have emmisions problems and reliability. would it not be smart to get a newer dated motor with more capability's. i know some if not many hate the rx8 motor from what i see here. maybe i misconcept it. but rotaries strive on higher rpm. which we do easily and fairly. dont' know i'm not a FD, FC or RX8 genious. i'm just wondering is it HONESTLY worth it. i dont' want a i hate rx8's issue. or just non sense. i'm asking seriously. would ti be feaasible and worth the mod?


what ya'll think?

Los.

 

It's not that easy to take an engine designed to run N/A and make it a turbo. Have you see the problems the small Greddy turbo kit is causing on the RX-8? Plus, trying to fit a twin turbo system on that engine is not going to be easy.

The Renesis engine doesn't solve all the failing points of the rotary engine. They blow and overheat just like the 13B does. The benefit of the Renesis engine is close to power of the stock 13B-REW TT in N/A form. Turbocharging any engine puts more wear on it and decreases it's life. Just talk to 3000GT/Stealth owners.

 

I dont' mean getting a n/a rx8 motor and turbocharging it. i mean getting a n/a rx8 motor and keeping it n/a. just lets say street porting it and surpass our rew's horsepower. and still keep the n/a 's reliability.


los.

get what i mean?

 

i dont think he was talking about turbocharging the renesis, as much as he was saying to put an n/a renesis in a rx7 and get about the same power as a stock rx7 turbo rotary.

I think the conversion would be much more involved than hes thinking though, i dont know anyone who has done it. But alot of stuff is different, and getting a pfc to work on a renesis would be a HUGE project.

 

just take out the 13B-REW and use higher compression rotors (9.7:1), bridge port it and build headers and use ITB's...run a stand alone ECU. If you want N/A reliable power.

 

Three rotor renesis with direct injection near TDC. This would solve all your detonation issues (assuming you had a proper electronic monitoring system) and have massive power gains because you can bump the compression to 12-13:1 and the motor would still be reliable. Theoretically you could be in the 380-500hp range.

By the way Mazda already has this motor, but it's designed for hydrogen.

 

Even then, you are only barely surpassing stock FD performance, which isn't saying alot. Most likely a stock FD with a DP will be quicker. You could get the same effect by porting a 13B, and using a mid-sized single turbo at low boost.

BTW, there are built N/A 13B FD's. There were a few videos of one getting spanked by some Skylines on the highways over in Japan a few years back.

Really though, if you want N/A power, why go to the bother of swapping a Renesis? Since you will have to figure out a way to mount in the first place (as well as control it since from what I've heard, the Renesis ignition is a LOT different from the RX-7), just use an N/A 20B. More power and torque with already proven methods of installation.

 

I just figured it's a 13 copy with diff intake manifolds and i guess side housings since the exhaust travel changed. even though i know it's a barely more powerful n/a OR a slightly slower then FD with Downpipe. you'd get much more reliability. is a n/a 13b-rew worth it? or better a n/a FC motor? i know i woouldn't get anywhere new as much power n/a 2rotor vs a turbo 2 rotor or a n/a 3 rotor... but i'd like 275-300 rear wheel without so much hassle of turbo's degrading engine life so quickly. then again it also depends on tuning... but i like the sound of 13k RPM wankels =-) whatcha think? feasible/worth it?

los

 

Have you seen dyno charts of the non-turbo Renesis motor compared to the 13B-REW? I think you will be disappointed by the difference in power delivery, even in a ported N/A motor. If you want your car to be reliable, maintain it well and don't modify it heavily. You can't have your cake and eat it too.

-s-

 

see that pedal on the right? dont push on it so hard.

 

I thought I would chime in being a current rx8 owner and past owner of many rx7's....You spoke in the beginning of increasing reliability and prolonging engine life by switching to a renesis(se3p) motor. The power levels of a renesis are far less than even a bpu fd..Most of us have dynoed 180-190 bpu+ (intake, catback exhaust , ignition control and grounding kit). While even a bone stock fd usually generates 218-230 rwhp. I don't agree with the longevity claim as our cars are in the shop for issues and recalls-campaigns. I am amused that you are willing to take a motor that is damned and too restrictive in its engine management and control to produce worthwhile results from bolt ons or forced induction, when the 13brew although finicky without a proper tune yields much higher results when only the slightest mods are performed..

 

I've driven an RX-8. If you think the FD motor doesn't have torque at lower RPM's, just try the RX-8. It's terrible below 5000 RPM.

 

Yep, drive the RX-8 and drive the RX-7. Very different performance and seat-of-the-pants experience. If you doubt what you felt (which is a major difference in torque), you can compare dyno plots and see the numbers there.

As well, the Renesis apparently has different engine mounts, different tranmission, and no powerplant frame. You'd be further ahead making a 13B-REW into an N/A build than to fit a Renesis into the FD.

Dave

PS: this is in the FAQ.

 

Keep your boost levels stock with the FD and make sure it's in a good state of tune and it will be plenty reliable.

 

I'm not tryign to cheap out. or use the complete rx8 engine management sytems as some of you think. hence why i mentioned the power fc. being a stand alone it "should" be able to manage the rx8. then again i didn't know the rx8 motor had diferent mounting or a diff tranny. i figured it'd have the same bell housing bold pattern and use a rx7 tranny on rx8 motor like mazda has done in the past. i was wrong. like i said i know the torque band would be completely different, i figured in "theory" the sense that being n/a its' only 15 ponies short at the fly. it would be a worthwhile idea being parts are or should be more easily available to the new renesis vs our tired and scavenging rew's. it was just a food for thought. i'm not sayign i wanna get rid of my turbo or anything. i love it to death. but i just wondered would ti be feasible, worth it, and would we gain anything since i've read and been told na's last many thousands, double and more if taken care of. i know our rew's last a long time with proper care. but avg stock motors get 100-110k on the clock. vs majority of na's have gotten 150-200k before damage, and more when properly cared for. sucsk that it's so much different from ours.

hrmmm

los

 

i'd go 20B NA. Couple of guys here in Malaysia are already planning to convert. Considering the availability of 20B's in Japan i'd be playing around with this. Fuel management can be left to haltech or microtech.

 

WARNING: do not use the "bpu" jargon in conjuction with any rotary or rotor accessories. The hand of mazda will smite you.

have a nice day.

 

Bottom Line the $$ required to do any of this, 20B 13B/Renesis swap etc... all add up to a lot of money, and for that money you can go Single, or whatever.... why spend 10K lets say on a 13B to Renesis conversion assuming it can be done for that, just to loose HP, and gain 100k mi ??

Put in a turbo that can get you values that you're happy with, the GT35/40 kit can run 10 PSI (Stock Pressure) all day long and get you anywhere between 300-350 hp... without sacrificing engine life, since you did nothing to add to the strain !

And if you go above 10 PSI you know you're shaving life off the car, but if you're fine with that, it's worth it to you.....

Personally I'm going 35/40 @ 10 for daily putting around town, and I'll set the Profec-B to run 14-16 psi on the track, and that's what I'll tune it on, I just won't use the full amount of boost(14-16psi) 80% of the time.... I'll run on 10.....

Cake and eating it too.... BTW did I menation I have full spool (10psi) at 3000 rpm, which is not as quick as the twins, but if you go non seq, I'll be there right with you, and Pass you up pretty quickly after that...

 

^I'm having trouble with your post.

10psi on stock twins isn't the same at 10psi on a 35/40...so, you can't say, "since you did nothing to add to the strain!"

10psi by 3000 not as quick as the twins??? I would get 12 psi before 3k with seq twins and a few mods <---again apples to oranges

 

One choice for "whatever"....
http://hinsonsupercars.com/

 

Wait about a year and see what I come up with.

 

Thats an apples to oranges comparison. Thats like comparing the performance of a NA FC to the turbo II. Comparing the performance differences between a turbo engine and a NA is nonsense. The fact is if you remove the turbos from the FD the Renesis will have more low end torque and hp. Why? Because it has higher compression, a superior designed intake manifold, longer intake runners to help with low end, and more port timing. Hell the engine even has 3 window race bearings stock. Put the FD twins on the renesis and I can guarantee you there will be bigger improvements (down low & with top end) than with the rew.

 

I does have a PPF. It's a closed section PPF.


Some of you guys need to go search the Rx8 forum to get more educated. Some of you guys just don't realize how well that engine is truly engineered. There are racing organizaions that use stock Renesis parts in their race engines.

Here is a quote from another thread:

 

Rx8 has close to same power but the torque is much lower. Port it and there goes your reliability. Oh ya and the rx8 is 4 door. The problem is Asian people ( no offense) have a lot of pride, in 1995 the U.S. kind of dishonered them by only buying a few hundred fds. They had worked hard to produce a great car(fd) and we disrespected by not wanting it. So just like the aisan guy who left the craps table when the pit boss said he was taking to much time setting the dice. The rx7 left the us. ANd all these years later, instead of giving us a new improved fd, they give us a car with less power, less torque, more weight and 4 doors. The turbo charged miata is cool though lol.

 

First of all, there is no evidence that the Renesis will last 200k miles like previous n/a rotaries. Secondly, the cost of swapping a much lower powered Renesis into an FD would cost more than an engine rebuild and R&R. I'm perfectly content with replacing a motor every 5-7 years or so and enjoying 50% more power and double the torque of an n/a motor.