Hello Guys,

I'm about to commence a 3 rotor build with a short shaft eccentric. The car is a 1985 Toyota AE86. I owned this car in college 25 years ago, back then it had a 12A streetport engine. I sold it in the early 90s and have recently managed to re acquire it. It's in pretty bad shape (no engine, interior and lots of dodgy bodywork. But the restoration is worthwhile to me for the sentimental value.

My plan is to restore the chassis to as new condition and to use a 3 rotor as the powerplant. This will be a street legal car, probably driven only on weekends, and will have all the creature comforts (air con, power steering, stereo, etc). My choice of engine is simply because I've always wanted one, and the sound and smooth power delivery of a NA 3 rotor are well worth it.

I managed to acquire from another member on the forums a brand new 3 rotor short eccentric (presumably from New Zealand somewhere). Along with a new 6 port center plate, modified with the center stationary gear. In addition a set of FD rotor housings and plates, as well as three NA 9.7:1 rotors. My horsepower goal is ~300whp. And I'm thinking a streetport and a sensible rev limit of ~8000rpm should safely suffice.

For the rest of the driveline I'm considering a 2011 RX8 6 Speed and a GSL-SE rear axle. The jury is still out on whether these are robust enough to handle the power reliably.

This is a long term build (I have other race cars dealing with) and just want a really nice reliable and unique car. Any comments, ideas or suggestions would be welcome. Except those recommending I build a 13B turbo

 

Just a quick question for ya, why the 6 port centre plate?

 

That's what the kit I bought came with. I presume the previous owner was planning on doing peripheral ports. Hence the 6 port, which would have had smaller side ports to fill with Devcon.

 

6 port iron is used for the primary ports...I say it would have be modded with intent to use s4/5 irons.

 

I will be using FD irons with a mild street port. Was thinking of using Mazdatrix's 6 port street port template to open these up a bit

 

How does the center iron avoid uneven port sizes?

 

So i'd have to run 6 port irons all around?

 

If you want to run side ports and use 13B-REW front and rear side housings-

I would look into using 13B-RE intermediate side housings.

13B-RE on Left 13B-REW on Right-

 

but I have to run the 6 port side housing, because it has the third stationary gear necessary for tge3 rotor shaft. Are you saying I can keep that as long I use one of the above 13b plates as the "second" intermediate plate?

 

No, I was thinking you would have one of the 13B-RE intermediate side housings machined for the center bearing.

The 6 port intermediate side housing is going to be a real problem unless you go with full p-port and just fill them in. They just don't have much to work with.

 

OK understood. Is the 6 port that restrictive? Bearing in mind my whp goal (300)

I'm shying away from PP, simply because it's going to be a street car and noise and low rpm drive ability would be a high priority.

 

you could just go with a P port... then you wont have to worry about housings...

Also, the monster box 4 rotor just made a trip to Atlanta and back. which is a few hours drive on a 4 rotor Pported engine. The torque of the displacement alone makes it easy to drive on the street.

 

So it looks like peripheral port it is. Spoke to the Green Brothers in New Zealand, and they recommend a small periph intake (42/43mm). They say this should be fine for a street motor (300whp/8000rpm)

Driveability and noise not an issue they say. We'll see...

 

I just mean the 6 port intermediate side housing just makes it a lot more complicated if you wanted side ports.

You could port the 6 port intermediate as much as possible (really not much on closing timing) and use another ported 6 port intermediate for the other intermediate side housing and then fill in runners/port of whatever front/rear side housings you choose and re-port them to match the 6 ports side housings.

A lot of work and it will end up a pretty mild street port.

You could do the above and add semi- p-ports for more breathing capacity, but I don't think that will gain you any driveability over mild p-ports.

Or you can fill the side ports and just do a mild p-port as suggested by Green Brothers. You should be able to idle OK if it is a mild p-port with the right manifold/efi.

 

You mean fill up the ports in the end plates with something good like devcon and port them to match the ones I have now? What kind of airflow potential would that have? Power wise

 

I have no idea, I don't think anyone has done it.

If I had to guess I would think 250rwhp would be reasonable on the 3 rotor and 300rwhp would be about the max with a street port based on all ports being the same as max ported 6 port primary port.

I think it is probably the limit of closing timing on those housings that will keep you from making power in the higher rpms and thus keep you from bigger numbers.

 

That doesnt sound like it will turn out well. Why not get a new plate make up using an RE housing? I'm sure Chip or Logan could help you out...

 

There are machining instructions online for the 2 rotor 2 piece Guru shaft, I am sure the 3 rotor plate would be the same.