3 rotor build!
 

I'm debating starting a 3 rotor build for my fb. Unfortunately I don't know where to begin.

Anyone else do something like this?
I feel like all I'd need is an extra rotor/housing and a modified e shaft along with a few other minor parts.

Wow.....You have no idea what you're up against kid.....15k in just parts....

Cheapest way is to get a 3 rotor from japan (5K) and then rebuild it (2-3K).

Your right, you don't know where to begin. Start searchin and readin.

There is a thread in the 20B subforum about a 3-rotor 1st gen:

https://www.rx7club.com/20b-forum-95...gsl-se-967803/

Don't read it--it will just give you ideas that will cost you money. :) Seriously, if you want a 20B-powered car, buy mine The RXX-7 Homepage If you're interested, email me (there's a mailto on the website). Depending on the condition of your car, I might consider taking it as a partial trade-in.

You said in your post that you didn't know where to start. The short answer is "at your bank account". Unless you are a VERY skilled mechanic, tuner and fabricator, it will cost you a lot more to convert your car than to buy mine.

Sad to say but its true. Ive seen it said many times, and have looked into it and vaguely priced it out. I shall do the honor to pass it along.

"to swap a 20B (or have a RUNNING RELIABLE 3 rotor car) it will cost $10-15k...minimum"

and that is doing most of your own work/fabrication/modification

JDM 20b + rebuild + custom mount/install + TII trans/clutch/aftermarket flywheel (unless you want to keep it an auto) + aftermarket engine management (idealy) + wiring + fuel system + cooling....


...if i was gonna do a 20b swap i would un-turbo it, rebuild using S5 NA rotors, use a 3 barrel weber carb from an old porsche and some kind of "ignition only" engine management

Right on! I like the idea of a rack of side draft carbs. :)


Or just get a rack of 3 Kehini motorcycle carbs. :egrin:

Well nevermind then xD

lol, good thing you realize it now rather than 2 years and $6k later just to abandon it and end up with nothing :O

if i was going to do another 20B it would be NA with a 3 barrel carb/EFI. it would be a ton of fun

why N/a?

a few reasons, one i've done turbo 3 rotor's before. Two it should sound better NA. Three, its much much simpler NA, and i don't have to drive around looking at the temp gauge.

and forth, maybe its a P port

Do you have a lot of money? Or do you have a lot of fab skill? Or a dream and a prayer? Or just a lot of enthusiasm? Because enthusiasm can take you places.

I would go carbed all the way and not even any EFI. No computers!

i might as well, the weber carb is a 5 step process, tuning could be done start to finish in a couple of hours.

EFI takes longer (a 32x32 map has 1024 spots to tune, the carb has maybe 5), plus i've had some bad experiences with the haltechs...

how would you go about ignition then? the only thing ive ever even come across was a funky lookin distributor from Guru motor sports in Australia, was like $600. A standalone programable ignition system would probably cost less and require virtually no maintanance

That would be the fun part! Its definitely a good exercise to think about while
drinking beer :beer:

Besides its been done before. Heres the RB instructions for their old kit.

http://www.google.com/url?sa=t&rct=j...ELH5e8Kzq3vsmA

Do what I did. Add another pickup to a 1st gen dizzy. Keep the stock reluctor. Space the pickups 120° apart. Result: direct fire with late leading (wasted spark 180° like DLIDFIS). Worked great.

You can also add trailing. Get three more pickups, make a plate to hold them mounted just above the three leading pickups, get another reluctor and cut off two teeth 180° apart (because you don't want wasted spark on trailing!). Add it to the top of the shaft. I built this but didn't try it because trailing doesn't add power to the engine's output.

If you don't understand what I'm talking about, just go with the RB dizzy kit.

I was going to suggest something along those lines but I hadn't researched to know
if it would work. Thats some good info. Was that in one of your vehicles or a project
for someone else? Is there a thread on it here anywhere?

:nod:

Never let ignorance stop you from exploring an idea; you learn a huge lot more from finding out why something is maybe a bad idea than you do from slam-dunk cookbook projects.

that is exactly right. for example i did a 3 rotor in my FC, and i can tell you why the FD and Rx8 are 2 rotors!

Umm that sound like a lot of money is my opinion.

And to add to the problems of a 20B build, you also have to tune it. Something I'm going to have to get into pretty soon. Not looking forward to it.

When it comes to software etc, I'm not that good at it. But sit me down in front of a pile of wires and I'll Mona Lisa them for you.

Uhg, now I can't get a radiator to fit right. I should have moved the engine back when I had the chance. Or redo the motor mounts onto the main crossmember.

Pics?

We had a guy at the Woodward Dream Cruise (it's a metro Detroit thing) with a 3-rotor FC. It looked pretty good.

Just a question not like I would ever get the money to do it but would it be possible to custom machine a 4th rotor on to the engine. And if so what would it cost?