Ok, so now my baby is finished...and I'm bored.

So now, I wanna build my self a bullet proof turbo engine from scratch that can reliably handle +/- 400rwhp.

Here is what I was thinking, and tell me if I'm full of it....or if I'm spending money for no reason, like for unecessary parts. Also, this will be my first build from scratch so I dont know if every part I name fits with others I mention. I will need you guys help and expertise.

- RX8 Eccentric shaft
- FD Rotors
- S5 rotor housings
- S4 Irons
- Atkings rebuild kit
- RX7 Specialties 3mm apex seals

Is that the best I can get? Or would you guys do it any different?
Keep in mind that I have an S4 TII and I want to run premix.

Thanks a lot for all the help! I will make a build up thread to keep you guys posted.

 

This is a very strange combination of parts.

Sure, might as well.

S5 turbo rotors are the same thing.

For big power, the stronger and slightly lower compression S4 rotors are a common installation.

Rotor info: http://www.mazdatrix.com/faq/rotorwgt.htm

Only if you have an S5 ECU or standalone. Spark plug locations are different then S4.

Why not go with the stronger S5 irons? They are reinforced around the oil pedestal dowel area, and are reinforced around the water o-ring groove. Both notorious weak spots in S4.

Are your rotors worn past the point that they will accept 2MM? If not, then don't go 3MM.

 

Wow...ok...shows how much I know. I was told that 3mm apex seals were better at handling high power. Oh well. Thank god for this site.

So, to recap, I should go with

- RX8 eccentric shaft
- S4 rotors
- S5 irons and rotor housings
- Atkins rebuild kit and 2mm apex seals.

For +/- 400whp, I was thinking about a T-60i, (has to be external wastegate right? ) looking for .95 AR on hotside so it spools fast enough, 720 primaries and 1600 secondaries with a standalone (dont know which one yet, probably Rtek 2.0 )

Does that make any sense? I'm not a noob...lets just say I'm intermidiate. So I wanna make sure, and I insist on doing it myself, like I always do. And I always succeed...not without any problems though, but I always do.

 

What do you guys recommend for apex seals? OEM, ceramic...what?

Also, since all new parts are very expensive, what parts can I use in used condition with confidence? I guess that rotors are not a problem? I'm afrais of used housings though...What about irons?

And I saw people ressurfaciong thier irons and housings...doesn't that thin out the chromed layer? Does that mean that I will have to use 3mm apex seals if I have it resurfaced?

Sorry for all the questions. I'd rather mesure twice and cut once...and cheapness will bite me in the ***.

 

Used rotors are not a problem, so long as the grooves for the apex,side and corner seals spec out and they have no extreme damage to the faces - they are perfectly useable. As mentioned, for BIG boost cars, S4 rotors are more desirable since they are lower compression. And sicne they are slightly heavier, they offer a little more enertia for those drag launches

Irons are also something that can be found used in great shape. I find many blown engines actually don't eat irons since the chrapnel gets spat out the exhaust long before it has a chance to get caught between a rotor and iron....housings are another story though.

I would certainly go with OEM housings if you can afford it since your main sealing surface is apex seal vs. housing. Only draw back is cost. I recently put just under $1200 into rotor housings ALONE. For one engine

Honestly though, IMO, one of the most bullet proof and best platform engines to start with would be an RE or REW if you can find one. Fatter castings on the irons, larger ports to begin with, and all around just a little more modern. The RE can be swapped in VERY easily if going standalone + single turbo. All you need are motormounts (R.P.M. sells them as well as other vendors, albeit in the USA) and your FC accesories if you desire.

As far as apex seals go, ceramic are great. Highly durable (re-useable in most cases provided you don't detonate them) lower friciton, hardley any downsides that I actually know of. Aside from cost that is. These seals will cost you dramatically more then new housings....that being said, my recent engine has OEM seals......can't go wrong with Mazda! lol

 

So how does it work with resurfacing? And who can do that? Doesn't it thin out the housings and irons?

 

Anyone?

 

It's called a 20B.


-Ted

 

you might want to check nopistons.com/forums as they have a ton of info on engine build forum and you'll prob find a lot of your answer just by doing a search in there.

 

My car is running great with S5 rotor housings. Is it just TII's that differ or am I just easily pleased?

 

IMO, the location change of the leading plugholes between s4 and s5 is totally inconsequential. I have run s4 housings in s5/s6 engines, and s5/6 housings in s4 engines, everywhere in between stock and 450rwhp without issues.

I also think that for 350+rwhp goals 3mm seals are a good idea. There is very little drawback to them other than milling cost, and the required cornerseals/apex seal springs. They do tend to float and chatter a little more than 2mm seals at high rpm (about 7000 plus) but they are also 50% thicker and therefore more difficult to break. They can still be broken though, but it takes more abuse to break them. I have seen a lot more broken 2mm engines than broken 3mm engines.

That said, there are those that will always swear by 2mm seals for all applications. I like to say that it's similar to asking a group of guys if they prefer blonde or brunette; import or domestic; it all comes down to one's personal experiences and opinions, it's not really a "right and wrong" or "best" scenario.

No need to buy new rotors, ever...rotors are not really a wear item, as they "float" and do not contact anything other than the seals and springs that they house. As long as your slots are okay, the rotor is good to go.

If you have a lot of coin, then go with new rotorhousings and ceramic apex seals (and springs to match).

The rx8 shaft should not be necessary unless you plan to spin over 8500...same for the rx8 stat gears (which are also a drop in). Most turbos (on rotaries) seem to run out of breath around there anyway (even with an aggressive port), looking at the dyno sheets and riding in them.

Oh, and *some* of the s5 rear irons are reinforced versus s4, while others are not. The front and intermediates are identical from a casting/strength standpoint...I have never seen a reinforced s5 front and I dont think they exist.

http://www.rotaryresurrection.com/2n...ron_break.html