HI i just got my first rx7 its an 87 gxl na and im in the middle of a rebuild i want to keep the engine na but want some more power i got new actuator valves to get rid of the dead spot at the end of the intake valves it has a hks exhaust i will buy a header not sure what kind gets the best power so thats something i could use advise with and new apex seals and an na rebuild kit from atkins rotary i also have an intake charger i will put on just 1-2psi but i already have it so ill use it any way i need some advise on what i can do to the na to get the most power out of it i can ive seen people that have got 300hp out of the na motor but i have no clue how they did it so any advise would be great thanks im really excited to get this car done and take my first rotary powered drive once again thank you to anyone who can help

 

Please. use. punctuation. Then. someone. might. understand. and. be. able. to. help. you.

 

You make big power na by porting. 300+ power made by bridge porting. Not at all street friendly. a nice street port on a six port motor, you should see 20%-30% power increases. If its your first port job you best be careful, mess up and scrap an iron. Just port your irons and leave your housings alone. I also recommend pineapple’s street port template. It will help you do a nice clean job.

 

Definetely gonna have to port it

 

Thank you for the porting info. I forgot to mention when I put my first thread up that the engine does have a stage 2 street port job. It was sent to somewhere in Washington were it was done not sure how the street port works all I was told is it gives the engine more air can I still port the other parts of the engine or apply another port without damaging any thing or should I just build from the current port job with other engine mods to make the power I would like. I was told to get some bigger injectors, and racing bearings for the rotors I also need a new eccentric shaft do they make or sell any performance grade shafts? Thank you for the responses so far its very much appreciated. Hope my punctuation is better this time thanks

P.S. Heres a list of what I got so far If you know of something that would help even a little Id be very appreciative of your advise

Stage 2 street port on the 13b , Atkins actuator valves for the dead spot at the end of the intake , Racing bearings for the rotors , Bigger injectors not sure what kind to get any advise there would help , Also any advise on a good header for the exhaust would help , 2mm grade A apex seals , Intake charger for the intake of course its just 1-2psi but it should help right? , And Ill buy a chip for it need help there also , and the HKS rear exhaust thats all I really got for ideas so far so Thank You for the advise so far and taking your time to help

 

Well first, bearings will not produce more power, better bearings will just alow you to make more power safely. Secondly, where did you get your seals from? Atkins makes good seals but there are aftermarket seals out there that are compleate sh*t. Adding a port would be a bridge port. hard to do for a novice, and not street friendly. Raceing beat makes a nice header. you have two different sets of injecters on your car, primary and secondary. you need to know what size your injecters are before you can even think about trying to tune it. As far as the rebuild goes, your motor is an S4, produceing 140 HP stock. You can buy used rotors from an S5, which produced 160 HP stock because they are higher conpression. as far as other things you can do during your rebuild, you could buy Pinnaple racing's 5&6th port inserts. they look like little ramps and advertise 10 additional HP. I run them and bleave they do add some top end power. But if i were you i would stick with the ported irons you already have and just rebuild the motor around them. I hope this helps

 

This is great info thanks man. Any idea on were I could find some nice s5 rotors and can I still use the custom 2mm apex seals I already have? It sounds like i should stick with the current stage two street port and just build around it like you suggested. Thanks again

 

you can get a ported exhaust racing beat should have those.

 

rotaries don't have intake valves.


uh....wrong. porting the intake ports gets more air in. why would u not port the exhaust to get that increased air out? porting involves both intake and exhaust. besides, he said the engine is already ported.

jesses87gxlrotary7, check the 2nd gen classifieds section for used parts.

 

actually buying higher compression rotors wont do much...its the intake system that produces most of the power of the S5 motor, along with a higher redline.

 

A good fact to know is that getting 300 hp out of an n/a is costly
tuning would depend on what your going to use the car for.
because you could have 300 hp but if you have 20 in rims its gonna be hard to transfer that power to the wheel
a good guideline would be
fix or replace any problems on the chassis
start with a good exhaust set up ( all porting and intake tuning done to the car wont be at full potential without a good exhaust set up )
porting (you cant just open the ports up all the way there has to be a balance)
weight reduction (flywheel, wheels, clutch, driveshaft, ect. this will make the car react and accelerate better, and no it wont add hp. if your gonna drag race use the stock flywheel)
injectors/ecu ( i dont know any other company better than haltec for ecu's but they are very expensive)
brakes/suspension
these are things that can be done but there are diffrent combinations for diffrent applications. i would recommend talking to locals from the forum that race in your same application, and take in their feedback. one thing i cant stress enough is balance
sure an n/a can do 300hp but if all that power is between 8,000 and 9,000 rpm's its useless.

 

Uh, you’re forgetting that in addition to letting more air and fuel in you are also changing your fuel intake timing, meaning your allowing more time for your fuel to enter. As a beginner, porting NA housing is very difficult because of the diffusers pressed into the exhaust ports. These are made out of extremely hard steel, and are difficult to remove cleanly. In most cases your best bet is to remove, pound out, the NA diffusers and press in turbo inserts. Porting exhaust without removing the wings of the diffusers is completely pointless. And I posted that comment before he established that his irons were already ported. Please flame elsewhere.

 

Well what exactly do they do to the engine when they stage2 street port it? and i know theres no valves I'm just so used to piston engines. The s5 rotors wouldn't do much for power or durability? should I just stick with the ones I got? There in really nice shape. And I will buy the racing beat header seems to be allot of people that like them. And the intake system from a s5 would it bolt right up to my ported s4 thanks again for all the help guys

 

Porting is when the size of the openings that alow fuel to enter the engine are inlarged. S5 rotors will add some power, maybe 8 to 10 hp, but offer no change in durabilty. changeing your intake to an S5 would be a pain for limited gains. better off just picking up a turbo2 ehaust mani and turbo and running low boost. plenty of people have changed the 6 port motor over the boost.

 

wasn't flaming anyone. all the ported engines i've dealt with always had the exhaust ports done. but didn't have these "wings" blocking the port. dealing with the old school engines i forget the differences in the late model ports.

 

In a Rotary engine, the port timing is equivalent to a camshaft in a piston engine. The higher the top of the port, the later the intake or exhaust is closing, and the longer the duration. On the exhaust port, the lower the bottom is, the sooner the port opens, and the longer the duration is.

I wouldnt recommend porting the exhaust if your housings are n/a. They have a diffueser in them which are directly casted onto the port sleeves. Ive had people ask me to just grind them out but this could result in damage to the sleeve.
When porting the intake leave the sleeve in if not it will result in loss of bottom end torque.
Any porting thats done will result in power in the mid to high rpm range

im not entirely sure about the s5 rotors maybe there will be slight compression gain(.7 i think)

Yes the s5 intake parts will fit but not the electronics, if you are worried about the whole maf and afm crap ignore it its a slight diffrence really. if you want a good manifold i would reccomend a holley.
If you just need a slight power increase work with the exhaust, or slap a turbo on it. If you are going to port remember without a good exhaust set up the gains wont really show their full potential. Look around the board for a turbo or aftermarket exaust, there are alot of part outs.

Also, adding power isnt the only way to shave seconds off a light flywheel, clutch, wheels, or driveshaft will shave some seconds off. plus these will increase the reaction of the car.
well hope this helps. luck'

 

is my 13b a six port i keep hearing about 4 or 6 port for the rx8s but not sure what mine is i need to know before i order any thing and thank you to all of you for the advice ive learned alot in the last little bit

 

As far as the 13b is concerned, all car build with out a turbo are going to have a 6 port engine, only the turbo 2 engines are 4 ports. The RX8 is a different engine entirely. And the S4 is any engine built between 86-87, and the S5 was built between 88-92. But your car was built with a 6 port engine, so it still should be unless the irons were switched to 4 port irons when they were ported.

 

Well this is the "valve" that activates the sixth port
if your engine looks any thing like this its a six port n/a

 

OK I think I now know what all i'm going to do heres the list

2 racing bearings for the rotors , a 2 piece eccentric shaft , the improved steel 2mm apex seals I got found out what they were , the racing beat header along with the check valve cover plate ect , the atkins actuator valve kit , 5th and 6th port inserts from pineapple racing , k&n cold air intake , atkins na rebuild kit , along with the stage 2 street port on the engine , a twin plate clutch , racing beat plug wires ,a atkins thermal pellet for constant oil flow to the eccentric shaft , lightweight fly wheel, and a performance chip.

Also thinking about sending my rotors in for a professionally applied custom coating any one ever do this does it add power and reliability?

Any one out there know what kind of hp and torque I might be looking at here and if its close to my 300 goal Id settle for 250 but the more the maier and the reliability it might have i'm building it for a weekend warrior and drive around on sunny days kind of car plus I love a good burnout. I wont lie I like a car I can really beat on the higher the rpm's go the happier I am. Also does anyone know the max rpm an engine like this will do? And at what rpm I can rev it to with out possible damage? Or if I have to remove the rev limiter to achieve max rpm range and power? And in all my vehicles I only run 91 octane or higher and its always done wonders for my vehicles will the rotary be the same way better mileage and performance not to mention less carbon build up? And if any one has any other tips or pointers or if one of these upgrades are unnecessary or I need something else to go with a certain upgrade it would be appreciated.

And I found out the stage 2 street port includes porting both intake and exhaust.

And thanks again for all the help especially roto racing and stickshifta and all others for the help. I'm really glad I found this forum its been a huge help

Would a port and polish help along with an engine balancing i'm sure those are two things that should really be done right?

 

Realistic numbers are more like 210-230 at the flywheel with these mods. Like a said before, it’s hard to make more power then this with an NA motor on the street.

 

Even running 2psi through the intake charger? but hey thats pretty close to 250 so I would be pretty happy with that as long as it was reliable at higher rpms and be able to do a burnout once in a while or the occasional donut or beating. Oh ya if I do these mods and straight pipe the exhaust with glass packs and cannons would I be able to spit out a flame or shoot pretty good flames the chip i'm buying makes the engine run even leaner.

 

on the whole octane to use if its n/a 89 is good enough unless your running it hard 91. octane usage depends on the compression of the engine engines that have to use 91 have a compression of 10:1 or higher and sometimes 9:1. thats why use 89 on regular driving and 91 on high rev situations.
if your running 91 on a low compression engine your just wasting gas and causing more buildup in the engine.
300hp is really hard to get on a n/a without sacrificing low end torque. with your seels if you let up youll probably be looking at 200 -220 maybe to the wheels if you lighten up the load.
i use ceramics but they are expensive but well worth the price.
still unless your irons are turbo you shouldnt port the exhaust unless you have diffrent sleeves for the exhaust ports.
after the porting and other mods top rpm will depend on the what the dyno says but a rough estimate would be 8.5k or 7.5 depends.

good luck on your build hope it goes smoothly.