I have heard various dissapointed reviews from people who have ported the Renesis. But, like RotaryGod said, the exhaust is what needs the most work, as Mazda really opened up the intake ports to raise that redline to 9k. The exhaust as we all know is a sheltered creature. It was so restricted from the factory to make 1/10th of the emissions of previous rotaries in order to be environmentally friendly. GL w/ the na tuning, but I feel that road eventually leads one to unfufilled expectation, and an eventual transition into the world of FI.

 

i think there will be some pretty good gains once when someone figures an easy way to fix the ignition system... until then, most of the gains you should have in the top end aren't going to show up

 

Well, that's always a good scenario to look forward to, but to put sumthing in perspective, 2nd gen motors and 3rd gens w/o the turbos are so weak compared to the Renesis N/A. I mean, it's not to farfetched to say that mazda accomplished a hell of alot to get the Reneis, (an engine of the same 1.3 ltr displacement) to put out as much power as it does from the factory w/o FI. So, at least for the meantime, I think most of what NA gains that are gonna be accomplished out of a 1.3 ltr wankel, Mazda has done the majority of it. Now, talk about a 20b and thats some serious power w/ or w/o an FI setup.

 

What about MPG of NA vs. FI? I just completed an 800 mile roadtrip through wine country backroads at 21 MPG. Staying NA might have fuel saving benefits also. Average speeds are top secret, but let's just say I was using the NA powerband most of the time.

 

the exhaust ports may seem crappy, but there are two of them ... seems like quite a bit of area to me

 

There is more total port area but they also don't stay open as long as the peripheral exhaust ports do so it really comes down to flow over time and then quality of flow. The reason why the Renesis does so well with these ports is due to their port timing. Although the 13B exhaust ports flow better, their timing is too long in relation to the intake ports. A less agressive port timing actually helps power in this case.

 

rg,
check pm...

beers

 

I'd like to see someone play with the intake ports on the 4 port, personally.

 

Let's just say I'm with you on this one but what about the turboed vti you mentioned?

 

??? Nothing there.

 

this is really newbish of me but what does N/A mean?

 

...Well everyone is a newbie at one point, and in so many ways we all still are. N/A means Naturally aspirated

 

odd,
sent again..

beers

 

you are full or i am blocked...

beers

 

Is it a secret? LOL

 

not from you.

pm me if you want to know....

beers

 

Just an example of what I would prefer and since a turboed typeR would be again faster than a N/A, I compared it with the older engine. Back on topic though.

 

Wow, it's been ages since I last posted in here.....

Anyway, just to give you some more info on this whole "going-the-N/A-route" thing that peloponissios and many other RX8 owners are considering in Greece.

Peloponissios posted his last mods in one of his previous posts (REVi, single exhaust, headers, cat, reprogramming, and various bits and pieces), with which he has seen some nice power increase. Not anywhere near the stock HiPow output of course (231HP crank), but a far cry from the 192HP of the StdPow version.

However, what he failed to mention is the fact that his car is now incredibly loud. In our last meeting, we could hear him approaching the spot almost a mile away. He has admitted that this is TOO loud, but since he is aiming for maximum N/A gains, he will tolerate it.

Now, since I have my fair share of experience with 7s and port jobs, I believe that a ported Renesis with all the above mentioned mods will simply be intolerable. Not only from the inside, but from the outside as well. And if we consider an rather sizeable increase in consumption, AND the fact that the power increase will not be anywhere near a modest F/I setup, AND the fact that it will cost an arm and two legs, I believe that maximum gains with a N/A setup is ONLY for people with too much money and even more free time on their hands....

A modest 4-6psi setup (Greddy, SSR, whatever) will be at the same noise levels, have a slightly lower MPG, will be completely driveable, and will not break the bank

Why am I posting all this ? Because I am also considering the dilema N/A or F/I, and apart from some nice and very specific power mods that I already have (Trust PE Ti, REVi + R/A), I don't think that there is much more room for anything else....

 

I doubt most, if any of you know him but Kahren will do porting on a Renesis if people are willing.

He does some very nice work and has made some great gains on rx7's. He took an s5 (1989-1991) engine and rebuilt/ported it with a stage 1 style streetport, midpipe/catback, cone filter, stock ecu with s-afc and got near 200rwhp. This was also before redline, he had to let off because it was running too lean and was maxing out the stock fuel system, but the power was still climbing. Also, in stock form the s5 engine puts out 160 hp at the flywheel, so this is a fairly good gain.

Anyways, he's willing if anyone actually wants to. His prices are VERY fair also. He gets rebuild parts for good prices and doesn't charge much markup on the actual assembly/disassembly. Then porting is only a few hundred on top of the rebuild/assembly costs.

 

I hope this doesn't come off as pessimistic, I'm just curious.

How many 8s has Kahren ported so far?

Is porting a 7 the same as an 8?

Where does the car have to go to get the work done?

 

I'm still dreaming about an afordable NA 3-rotor kit for our cars making 300whp...if only it wasn't just a dream, lol.

 

He hasn't ported any Renesis engines yet, but tons of other rotaries.

Porting characteristics are generally the same. He's spent a lot of his time experimenting with different styles/shapes to see what works best from his view.

He's in Connecticut. You can either bring your car to him, or ship him your engine. He's flexible most the time on working stuff out.

 

Maximize NA??

Pulley set - 2-3hp or maybe better
Flywheel
Revi intake, or AEM + ram duct - 5-10hp
TurboXS exhaust + TurboXS race pipe, or RP supercat - 20-25hp
Interceptor X - 20hp

50-60hp gain is possible with N/A mods and it costs alot of money, but that's the way i'm going

 

You'd be lucky to get 50-60 from all that stuff even if you threw in a good porting too. Without porting you won't even come close. Unfortunately, you can't just take HP numbers from manufacturers and add them up. It doesn't work that way.

 

As stated in many other threads, you won't get that much power from all of thoose mods but that is a good list. I would add.

Lightened rotors
Exhaust Porting
Ignition
Lightening car(for better power/weight)