The Great Renesis Porting Project!
 

(besides me ) :D
just wanna discuss porting techniques, port timing and stuff like that.

I'm just curious what you have done to yours?
Judge Ito won't reveal his mods, so maybe you will?

i want to get mines ported but cant find a shop that has experience doing so.i called ito shop but hes to busy.

What kind of discussion do you want? I've played with the Renesis housings. I know what they look like and what you can do to them.

Care to share this with us RG?
Or direct me to the correct area of the forum if you have already posted this.

i'm not an expert on renesis engines by any means, but i'll share what i did. feel free to critique, but try to be positive.

the intake is great to begin with, so not much there. just beveled the edges and brought up the inner edge to look a little more similar to the 4 port config. and for the rest, just the usual stuff, deburred the runners and on the secondary ports, there was a lot to be removed from the outside edge leading into the port runner. not very drastic though--i think the power is gonna come from the exhaust.

and for the exhaust...
i advanced the port opening a bit, but again, nothing drastic. the exiting gas has to make basically 2 90 degree turns to exit the engine. not really good for flow--which may be part of the contributing factor to exhaust systems not adding a whole lot of power (according to racing beat, anyway). i believe the restriction is in the port itself.

so i gave it a big radiused edge, and angled the boundry layer instead of having it come straight down, then make a 90 degree turn. it now starts at about 70 or so degrees, and makes a nice, gentle roll towards the sleeve. (this is all from the top view perspective)

and in everything, i was keeping the "line of sight" in mind. if you can see the combustion chamber from the outside port exit, it's good. the less turns, the better.

so that's what i did in a nutshell. i'd appreciate any constructive critisism if anyone has any so i can do an even better job next time. if anyone else has done it and is willing to share, i'd like to hear about it.

guitarjunkie, how does she compare ported vs stock?

The exhaust sounds a lot like what is needed. If it were possible to get some custom exhaust headers, i'd say remove the sleeves all together. Did you take any pics?

I'd love to see a dyno too.

haven't taken pics because i gots no cam :(
if anyone is close to hesperia, i'd love to get some taken--i'll buy lunch.

and as for how it runs... i don't know, and i won't ever find out. this engine is going to get turbo'd when it goes back together next week. i really want to find out though. i bet it would make quite a bit more power throughout the rpm range.

one thing i forgot to mention before is the water jacket! it is extremely close to the port wall. being the redneck i am, i hogged right through it and took it to a shop and had them weld it back up, then i cleaned the port up again. fairly simple, but worth mentioning that there is not very much you can do to the exhaust port without going through the wall.

Sounds great...... keep us updated.

will do :)

did you do the porting yourself?

sounds good and can't wait to see some pics and #'s with the turbo on it.

I'd love to hear more about porting the renesis. I wish more people would do it so that I could get a feel for what it would do power wise, go port your engines!! :D
I'd really like to see comparitive dynos with and without porting and maybe some timeslips. I know Ito should hopefully have some of that soon, but a larger sample space is always better for measuring averages. Thanks to anyone with more info, and to guitar for his writeup.

if the sleeve in the intermediate iron was removed, it'd free up heaploads of space in the port. anyone know if the motor would care if the exit wasn't divided? would it maybe be a good idea to remove all the sleeves? or would that be detrimental to anything?

this will have a custom turbo manifold made.

Where are you getting the turbo done?

Not to hijack your thread or anything, but there are a great deal of us looking at FI. There is just one thing stopping us, engine management. What are you going to use for your custom turbo setup?

we're still looking into what to use for fi.
i used to be a big haltech fan..until the "x" series came out. that pretty much ruined it for them.

the aux ports may or may not go back in. we might test it both ways and see what's up. in any case, they're going to be a bitch-as they're electronically controlled, instead of pressure actuated like on the 2nd gen rx7's. my prediction is they'll probably end up being omitted and we'll just deal with the low end, but don't quote me on that yet.

in the end, we may leave the stock computer in there, and use either a piggy back, or a combination of that, aic, and ignition timing control. it's still up in the air right now.

Interesting, I'm sure a lot of people here would love to see your results. Keep us updated, thanks.

yup yup.

I don't see alot of potential for the intake ports. I'm not going into bridgeports since we really don't know how the engine responds with less drastic forms of porting yet. No need to jump the gun.

On the intake ports, I would mainly focus on the short turn radius where the port runners turn into the ports entering the engine. It sounds like you have done this. I'd also add a minor bevel or radius to the closing side of the ports. Nothing serious that would necessarily enlarge them. Just take the sharp edge off of things for seal longevity. I would probably enlarge the primary ports a little. They really can't open any earlier but they can close a little later. I wouldn't even enlarge the auxillary ports to make them close later either. You can get too late. Try to convince the RX-7 guys that. Basically it's extend the closing time of the primary ports a little and work on the short turn radius of the runners.

The exhaust side needs more help than anything. If you hit the water jacket, you went much more crazy than I would. The ports can be opened quite a bit earlier but I wouldn't go down any farther than the bottom of the exhaust runner. Those who have never seen a Renesis taken apart may be a little confused by this. There should be no issues at all in regards to hitting the water jacket. The short turn radius of the exhaust ports is absolutely horrid. It is very sharp 90 degree bends. The sleeves need alot of grinding down to take care of this issue. It sounds like you got that taken care of if you can see inside the engine through the exhaust runners. I would not just remove the exhaust sleeves. You probably won't get as much from this as you think you will but you will succeed in getting more exhaust runner area. This isn't necessarily a good thing since the ports shouldn't be able to outflow them anyways. What you will do is to slow the exhaust gasses down and hurt low end performance more than just leaving them alone. Machining a new center sleeve may prove worthwhile. I'd personally like to see each exhaust port have it's own runner and then use more of a conventional header. The exhaust ports in the engine are so restrictive stock and kill the velocity through the short turn radius to the point that any benefit you get after this point is irrelevant. Combine this with siamesed center ports and no port overlap, and you have an exhaust that can't help you at all. I believe with porting and seperation of the center runners that this can be changed.

I wouldn't worry so much about Haltech. If you like their older stuff then by all means use an older ecu. You will need to use a conventional style throttlebody though. Only the Motec systems that I am aware of have the ability to control drive by wire. I think you should leave the S-DAIS system active. With the exception of the auxillary ports, the rest are all vacuum or rather pressure actuated. This would be very easy to set up using positive pressure air from the turbo and rpm activated vacuum switches. It is simple. The electric auxillary ports could work based off an rpm switch as well. Keep all of the off boost drivability. Leave it all working. It isn't hard to do. You are going through so much trouble. Don't skimp here. Also I wouldn't use the stock ecu with a piggyback unless you absolutely have to. Always use a standalone if you can. The stock ecu still makes tuning a bitch. change over to a more conventional fuel system as well.

If you are going to all of the effort of porting it and fabbing up forced induction, finish the job with a better fuel system and ecu as well. If you don't, you'll probably end up doing it all again later.

Great post Rotarygod. This may seem to be a strange question for this thread, but what do you do for a living? Are you a mechanic or something of the like? I don't mean to pry or whatever but you know so much about just about everything there is to know about motors. Why not open up a rotary shop?(unless you already have one?) Don't mean to hijack, I'm just trying to get RG to start porting our engines :D

I'm a real estate agent! I just work on my own and freind's rotaries alot. I also played around and studied the Renesis housings at Racing Beat during Sevenstock weekend. You learn alot just looking at them.

I'd love to open my own rotary shop up. This wouldn't be hard since I would just tack it on to a friend's auto performance shop. He's offered me the opportunity. The hard part is knowing that I'll have steady traffic and therefore income. Time is already at a premium. I'd really have to drastically reduce my job as a real estate agent and I don't think a rotary shop would pay as well. There is alot to think about. It would be better if I just trained my friend to work on them. He is almost exclusively just a track car person so regular performance minded ricer types just don't go there. He does have a 4 wheel dyno on the way though! It will be installed in the very near future. He's got 4 lifts, a tire changing and balancing machine and an alignment machine. It would be a nice setup. It would just require too much money up front and too much of my time. I'd rather get ahold of a car and develop bolt on pieces and just sell and install them through him. This is more realistic but even then I'd need a car to begin prototyping with. That still leaves me with the time to do it dilemna. Oh well. It would be fun but I don't think I'd want a career out of it. I would like to be an Axial flow supercharger retailer though.

thanks a lot for the input!!
a few things i'd like more clarification on though:
1) intake closing time. i can understand the adverse effect on a naturally aspirated engine, but i think it would help a turbocharged engine (once the turbo gets spoolin' anyway). in any reguard, i only extended them about 1mm of actual removal. the rest was just the bevel.

2) i'm unclear as to whether you're in favor of removing the sleeve from the intermediate housing. did you mean to remove it, and machine a new one that is fully divided? the runners are just tiny tiny...i'm wondering if it might help to just get rid of the center all together. (keep in mind it's only on this one turbocharged engine).

thanks again for the good advice. exactly the kind of constructive critisism i was hoping for. major props!!

Might want to contact Racing Beat. i know they have done a bit on porting the Renesis, maybe you could offer some valuable insight to each other. I know somebody asked Jim M. during the session if they had ported the Renesis, and he said they had, but only came up with about 4-8 hp, not much.

You have to consider that you can only get so much air into the engine with forced induction regardless of timing duration. Let's just say that you are running 10 psi of boost. Once the pressure in the engine reaches 10 psi while the port is still open, you aren't getting any more air into it. There's no point in holding the port open any longer. You want it to start compressing as early as possible for best power. With low port timing you may or may not ever get to this point since the engine may never reach 10 psi while the ports are open but the 6 port engine has an awful lot of time to fill up, especially when the inlets are smoother and flow better and faster. The auxillary ports already stay open until 80 degrees. How much later do you need them open? A mm probably won't matter much but you still can get too much timing, even on a turbo motor.

I favor a new divided exhaust sleeve. Unfortunately you can't get around fairly poor flow characteristics here but you can improve on them. The problem with removing the sleeve is that the hot exhaust gasses from one rotor will directly blast the other rotor. This will also send a strong pulse directly into the other chamber. You don't want this. The runner area for the exhaust may be tiny but take some measurements and determine the total area for each rotor. Now compare this to the total area for the older engines. Here's a hint, the old engine exhaust sleeves expanded greatly over a very short distance. The 2" pipes that everyone uses are much larger than the exhaust port area. They are actually only equivalent to a 1 5/8" pipe! I'll bet the Renesis has more area than that.

If you try a divided sleeve, also try a completely seperate true dual exhaust setup. One pipe and muffler per rotor. No collector. I'll bet the car has tons more low end. This setup works great on low overlap engines.

i'll try that if i get another one to do, but this one gets turbo'd :)
i really do appreciate the help.

is anyone else interested in having some porting done?
i can't afford to do it for free because carbide costs me money...not to mention i spent like 9 hours on this one. but i can do it basically for the cost of the materials i use and maybe a bit on top of it for labor...but mostly just to see what kind of power it will make.

only concern is i don't have any idea how much power it would make, so there is some risk involved. i'd really love to see before and after dyno sheets.

i'm very interested.

where are you located?

i just don't want to risk my engine being damaged :)

didnt ito get like 50 hp when he ported his? and jim from racing beat says they only got 4 to 8 something not right.

I don't think Ito will say what he did to his car exactly. I would find it very difficult to see that the renesis gets anywhere close to 50 hp from just porting out the engine. Unless you are pushing more air into the engine (FI) this engine is already pretty well tuned. If somebody got 50 hp from just porting, I would rocket my ship to the nearest Mazda specialist and work on this as we speak. I remember Jim M. mentioned specifically that there was not nearly the amount of gain from porting the Renesis that there was from the previous generation rotaries. Could very well have to do with the design of the engines, but also that the other cars were FI'ed and able to use the extra intake, etc.

Actually when I talked to Jim, he never claimed any internal port work as of yet. He was more concerned with getting bolt on products finalized and then later on moving in to that arena. The person that claimed they have ported it was just a little part time guys. His story was never even consistent. The numbers Jim was talking about were just the bolt on gains so far. He's only seen 4-5 hp with headers, 3-4 with an intake, and a few across the exhaust. He has stated that he didn't think there were many gains to be had from porting since they were done so good from the factory but then he went on to say that the exhaust ports in the engine are terrible. This is a contradiction. We won't know for sure until we see one ported and someone actually takes pictures and verifies it after it runs.

Ito claims he hit 240 rwhp on his just off of bridgeporting the auxillary ports. His dyno looked strange to me though. There was a several horsepower peak where it jumped up to that number but fell down above and below it. I don't mean that power just improved when the auxillary ports opened and then climbed up to redline. There was a small peak in that rise and that is the number he quoted. That is worthless info. His power peak also came at about 7000 rpm or so when it should have come at 8500. Something is wrong with that. His motor is peaking where the 13B's should peak rather than where the Renesis should peak. The stock ecu also can't compensate and he claims that it hasn't been touched. He's done good work on rotaries in the past but he doesn't ever tell you anything useful and his dyno claims are misleading. It is also very rare that you ever see any pictures of his ports. There's nothing secretive about enlargening a port. You can stare at a picture all day but it doesn't mean that you can copy it.

Judging from the several rotaries I've ported so far, I don't see it taking me 9 hours to port. You can actually enlarge each port in about 15 minutes. The long part comes in cleaning them up and getting them smooth. It would still probably take a good 4-5 hours though. Don't even get into the time it takes to cut a bridge. I've done them and they suck to do.

Well the dynos don't lie. Maybe the truth has been stretched, but he did hit that number. I'd like to see pictures as well and some greater explanation, I love learning about this kind of stuff even though I'm pretty new to it. I hope Racing Beat has some success with porting the engine when they get to that point, they're a group I'd trust to screw around with my engine. Thanks again for all of this info RG.

Rotary god

If you are as good at selling real estate as your knowledge of rotaries , you should be retiring pretty soon :D .

Combining a rotary workshop with a realestate office would be :cool:

After spending 23 years in realestate 10 years in my own bussiness now i am finally taking it easy playing with my toys . ;)

cheers
michael

I understand that dyno's done lie. He has also just hit a very similar hp number with his daughters 6 port RX-7 engine. Maybe a dyno doesn't lie, but how do you know the dyno you are looking at is for the engine you think it is? Something to think about when believing dyno claims.

Yea I guess so. I'll take your word since you'd have more knowledge on this subject, but I'd still like to see some more info from it. Time will tell.

Dyno's don't lie, but they can be "tweaked". I'm not accusing any companies of doing so, just pointing out its possible.

1) Redyno the vehicle over and over again, until the perfect conditions are met.
2) Compare a just warmed up car, to a heat soaked one.
3) Turn the AC on for one run
4) Adjust the straps inbetween runs
5) Dyno the vehicle on different days, at different times, under different environmental conditions.

A few other ways, but they escape me right now.

as previously stated, there's not a whole lot to be had from the intake. the engine can suck plenty of air in. now getting it out is another story...

Do you think that there is enough to do with the exhaust ports to open up 50+ whp?

rotarygod what do you think the chances of porting only the the exhaust exit with the engine still on the car.i would remove the the manifold and start to grind away??

You can't. The exhaust exit that you can see is not what needs attention. It is the physical port openings in the combustion chamber that need the help. There's nothing you can do from the outside.

thanks rotarygod.that sucks because i cant get anyone who has experience to port my engine all the shops i call have never done an rx8 ,i called ito shop but he is to busy :rolleyes:

if you want to take a small gamble, i'll port them.
i'll even do it for free--except the cost of the barbide burrs consumed ~$50.

all i want is before and after dyno charts.

it is a small gamble, but i do think it'll build more power throughout the rpm range. there's just no reason it shouldn't. i'm not sure what the actual hp gain would be, but if you see the before/after ports, you'll realise how much better they will flow.
if we do that, i don't want you to change anything on the car--no exhaust, intake, nothing except maybe just making sure the air/fuel ratio is about the same. i'd want to see what the porting alone gives power-wise, then we can see how much of a difference everything else makes.

quitarjunkie were you from ?

hesperia, california.

oh your to far away.iam in new jersey ill be heading to las vegas on wensday.wish you were closer.thanks anyway

no problem. vegas is like 2 hours from me.....3 if you go the speed limit

actually, do you mind driving a couple hours? you can see the irons and take some pics if they're still here then.

alright.
first one is basically free--just reimburse for the materials... after that, i'll get some kind of a price together. there's a lot more work than there is with the rx7 motor....that's for sure.

Wow I usually just stick to reading the aftermarket section but I'm kinda glad I came over here. Junkie I live in Rancho it's about a half hour from you. If you're still game I'd love to work something out. I of course have no problem driving out there. My girlfriend lives half an hour away in the other direction so I'm used to the drive. The 15N is a bitch but we'll figure it out. Just lemme know and we'll PM.

Edit: Also my car is stock (unless you consider a green air filter to be a mod :p ) So we would see some interesting dyno figs.

cool. whoever is first then...

rancho is closer to 45 minutes, but still well within range. remember, i want before and after dyno sheets with NOTHING else changed.