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-   -   My 3 rotor FC build (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/my-3-rotor-fc-build-142594/)

usfdr 12-21-02 04:13 PM

My 3 rotor FC build
 
Ok guys, I'm posting this in the 2nd gen specific area because it is a detailed thread that shows what it would cost to build a 3 rotor FC. If you guys feel it belongs somewhere else don't hessitate to move it, wont bother me.

Anyway, I started this on the teamfc3s.com website in the pictures section (if someone wants to check it out) to show exactly what it would cost to build one of these puppies. Originally I was going to put it in my 88 convertible, that I'm converting to a 91 by the way, and then decided not to after researching all of the extra support the car would need to handle the extra torque. So, I decided to put it my 91 coupe which is in mint condition with 85,000 original miles.

As for the engine I bought it from Nippon Motors in California. The engine was flawless and really shoudn't of been pulled apart but oh well. I decided to beef it up a bit. I got it street ported, slotted the rotors to 3mm, and added a bunch of extra dowel pins. All of the interals are new to include 3rd gen main bearings, 3rd gen corner seal springs, and solid corner seals.

I'm also going to keep the sequential twin turbo setup but they are getting rebuilt and upgraded with larger compressor wheels and clipped turbine wheels.

Lets see some pics and then I'll start blabbering again.

usfdr 12-21-02 04:15 PM

If any one can tell me how to post more than one pic at a time it would be very helpful

usfdr 12-21-02 04:17 PM

After everthing was stipped off

Bridgeported 12-21-02 04:23 PM

AWESOME! I can't wait to watch the progress of your build up!

usfdr 12-21-02 04:35 PM

Ok, so far this is what it has cost me.

91 Coupe (mint but needs paint) $500 minus eng., trans...
3 rotor shippped $2,550
Streetport, slotting, extra dowls $1,310
Engine Mounts from teamfc3s.org $250
Upgrade and rebuild turbos $700
Konig Villians 17x7 and 17x9 with 275 Nitto 555r's in the rear $800
RP competition fuel pump $200
complete reduild package about $1,300
That brings the total to $7,610 including the car.

I still need Paint, Radiator, Intercooler w/ piping, Exhuast, and I'm powder coating the monifolds and the piping, Dry Cell Batt., and some misc stuff I'll probably need. I should be able to do all that for $2,400. If so I'll have a sweet car for, hopefully, less than $10,000 that will beat down those Porsches, zo6's, and maybe even some Ferrari's. All this and its still an everyday driver with A/C, Powersteering and complete interior.

Let me know what you guys think.

usfdr 12-21-02 04:37 PM

Almost forgot I need a clutch, flywheel, and pressure plate.

usfdr 12-21-02 04:43 PM

As for Horsepower I'm looking to get about 475 to the wheels, we'll see.

RX7withNitrous 12-21-02 05:12 PM

are you putting the engine in yourself?

Aaron Cake 12-21-02 05:19 PM

Looks good! But two things:

1. The stock ECU is very limited, and while people have had some success running it in the FC, an aftermarket ECU is worlds better.

2. I have never figured out why people would go through all the trouble of the 20B and still use the stock twins. :) But I guess it's a personal thing.

FCdemon 12-21-02 05:28 PM


Originally posted by Aaron Cake
2. I have never figured out why people would go through all the trouble of the 20B and still use the stock twins. :) But I guess it's a personal thing.
my guess is that people want the 20B over a 13B-REW because they can get *reliable* high output, without stressing the engine too much whereas the 13B would be getting harder to keep together at those higher power levels.

FC_Iria 12-21-02 05:37 PM


Originally posted by Aaron Cake
Looks good! But two things:

I have never figured out why people would go through all the trouble of the 20B and still use the stock twins. :) But I guess it's a personal thing.

Some people can't afford to go all out at once :) Plus 3-rotor has more potential then a 13b-REW.

Here's another question. What are you using for a tranny? Will the 20b bolt up to a TII tranny?

Aaron Cake 12-21-02 05:39 PM

Well the thing is, it's a lot easier to swap the turbo(s) with the engine out of the car, and then you only have to tune it once.

Part of reliable power is using properly sized and efficient turbos for the power level you want. Overstressing the stock units to bump the power output is not necessarily reliable. :)

I would hope that he is using the TII transmission. The 20B will bolt to both the TII and NA unit, as long as the proper clutch and flywheel is used.

Bridgeported 12-21-02 06:01 PM

475 rwhp on a streetported 20b will be easy. Lots of guys put down 500-550 rwhp on stock twins 20b engines at 14-15 psi.

Scott 89t2 12-21-02 06:26 PM

haha good luck on your under 10k budget...

do you plan to cut a hole in your hood to clear the thermostat housing? that would be free... and drive with no front sway bar?..

and good luck running the stock ecu...

Bridgeported 12-21-02 06:33 PM


Originally posted by Scott 89t2
haha good luck on your under 10k budget...

do you plan to cut a hole in your hood to clear the thermostat housing? that would be free... and drive with no front sway bar?..

and good luck running the stock ecu...

The 20B->FC engine mounts he has alows you to do the swap and not alter or remove the stock sway bar.

I am not sure about his exact ones, but most 20B-> FC mounts also lower the engine enough that it clears the NA or TII hoods.

The stock ECU does suck and is realllllly hard to get to work well.

BlackRx7 12-21-02 06:48 PM

I'd like to see this guy actually get this together, instead of critizism, tell him what he should do to make his car have the most potential

Capn' Wankel 12-21-02 06:49 PM

umm the whole thing sounds great but I believe that you should visit the 20B forum in this website to actually get ur costs correct......talk to evil aviator(the admin for that section) and he will be able to give you the tips you need to actually put the engine in your car. I think that Scott89t2 has a couple very valid concerns involving the thermostat housing and the sway bar. I believe that evil aviator and his close friend had to redesign the thermostat housing from scratch and have a machine shop mill a piece of billet aluminum to the appropriate size..... and he had to have a custom sway bar made to clear the block. And finally.... I think a point brought up in the hundreds of 20b posts before all pointed at not being able to use the stock ecu from a cosmo .... so I think that you may be looking at another 1-10 grand based on a computer for the car.

3isacharm 12-21-02 09:16 PM

i was about to ask the same thing about the ecu. supposedl the tecIII system can do it and microtech. the only downside i see to those, is cost (tecIII is like $2500) and tech support (unless you live in australia, microtech users seem harder to find). i'd love to see this thing come together for around $12k total, that'd give me a little more motivation to get it done. i wouldn't even need half of that crap (street port, rebuilt/modded turbos, dowells) to be happy. btw, how much does this engine weigh?

hybridracer 12-21-02 09:25 PM

mu mu mu mu mu must have 3 rotor.................................... :)

RX7withNitrous 12-21-02 09:30 PM

how much would it cost to put an fd engine into a second gen.

usfdr 12-21-02 10:03 PM

Ok well I'll try and answer some of these questions.

Yes, I am running the stock TII drive train

Yes, I am running the stock but yet highly modified twin turbos. I have seen this same setup make 450HP @ 5psi. I need to get this project going and it would be another year before I could afford a large single turbo, manifold, wastegate, downpipe, larger injectors, larger fuel pump, FPR, Fuel lines, suspension, Stand alone ECU, better clutch setup, and who knows the stock drive train might not even be able to keep up.

Yes, I will be able to run the stock ECU because I have this...

RX7withNitrous 12-21-02 10:05 PM

Oh well since you have that.......:cool:

Evil Aviator 12-21-02 10:18 PM


Originally posted by Aaron Cake
2. I have never figured out why people would go through all the trouble of the 20B and still use the stock twins. :) But I guess it's a personal thing.
I highly recommend this. My car would have been running a long time ago had I done this. The problem with going single right off the bat is that it adds a lot of work and another $10K or so to the project, not to mention the resulting drivetrain upgrade requirements due to the added torque. I think it's best just to get the thing running on the stock twins (sequential or parallel), and then upgrade from there once everything is worked out. Pulling the engine later to add a single turbo is child's play for anyone who has the skills to perform the 20B conversion in the first place. ;)


Originally posted by FC_Iria
Here's another question. What are you using for a tranny? Will the 20b bolt up to a TII tranny?
Yes, it will bolt up to a TII or NA tranny, but the starter fit may take some extra work. There really isn't any transmission issue to worry about until you add a large single turbo.


Originally posted by Scott 89t2
haha good luck on your under 10k budget...

do you plan to cut a hole in your hood to clear the thermostat housing? that would be free... and drive with no front sway bar?..

and good luck running the stock ecu...

LOL. Been there, done that, and realized that this conversion is going to take a lot more time and money than originally thought. :p:

BTW, the stock 20B ECU was made to run the engine at under 300 bhp, and the stock injectors will not support more than 400 bhp @ 40 psig @ 80% duty cycle.


Originally posted by Bridgeported
The 20B->FC engine mounts he has alows you to do the swap and not alter or remove the stock sway bar.

I am not sure about his exact ones, but most 20B-> FC mounts also lower the engine enough that it clears the NA or TII hoods.

No FC engine mounts alone will allow the 20B to fit under the hood line and also clear the stock FC steering rack with the stock oil pan. Some ways to get around this include relocating the steering rack, making a custom swaybar, using a custom oil pan or dry sump plate, moving the engine back into the firewall and relocating the transmission, etc.

usfdr 12-21-02 10:19 PM

That big mess of wires is the complete wiring for the whole car adn contains one of the essential pplugs for the ECU. Most people don't get this with the engine.

FCDemon is also correct I want a reliable vehicle that can put out some serious power.

Scott 89T2 you just need to do a little more research on your own. All of those problems have already been solved.

BlackRX7 thanks for the positive reinforcement!

Capn' Wankel why the hell should I visit some other thread to find out the costs that I'm already paying myself. All of the figures I posted were payed by me for the service described. Also, I am going to use the stock ECU (I've already figured out all of the wiring) so when I do you can let everyone know there wrong.

Hope this answers some of the questions. Keep bringing them on. I like to tell people the truth instead of spreading something I heard on another website. Don't mean to sound like a dick but I hate it when people do that. I belive that if you don't personaly know or if you haven't seen it in person then don't spread it around like you have.

Thanks,
UsfDr. (Sean)

usfdr 12-21-02 10:32 PM

Evil Avaitar thanks for the added input. I have been worried about the swaybar issue but I wont be able to talk about it until I actually set the engine in the car with the mounts I have. As for the stock ECU problems there are many things that FC owners do right now to overcome the stock maps of ECU's: S-AFC, FCD, piggybacks, standalone fuel management. I'll let you know exactly what the stock ECU can do once I get it running and on a dyno but right now we all are really just talking shit. since the aren't that many people running the stock ECU (other than Cosmo guys) we really just don't know what it can do except for what we read or hear about.

I also agree with you about the stock twin versus large single situation. I have thought about it many a nights and after carefull consideration I decided to go with the twins. Please feel free to add more as I too need to gather as much information as possible from people who have actually done or are doing this conversion.

Thanks,
UsfDr


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