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-   -   FD Twin Turbos on an FC (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/fd-twin-turbos-fc-1047939/)

VasiliBrown 10-03-13 11:23 AM

FD Twin Turbos on an FC
 
Found stock FD twin turbos on craigslist with wategate, piping, inter cooler and blow off valves for a good price. Will I be able to put them on my 1991 rx7 convertible

VasiliBrown 10-03-13 11:35 AM

By the way my 91 rx7 is naturally aspirated at the moment

Claytons91 10-03-13 11:44 AM

short answer.... no.

Customisbetter 10-03-13 12:06 PM

Nope. The NA intake system won't fit. You sould try to add the REW intake but that would take a crap ton of modification. Not worth it.

FC3S_nataku 10-03-13 12:11 PM

What about on a 4 port? Would it make sense then?

Customisbetter 10-03-13 12:22 PM

It could work but you would need the FD upper and lower intake manifold. At that point I would just fab up a whole new intake setup.

You would also need a "good and working" solenoid spider from an FD of which there are few. Plus an FD ecu and Power FC.

But at that point I would also just buy/fab up a new exhaust manifold and runa single turbo.

There really isn't any reason to use twins anymore.

oinesra 10-03-13 12:40 PM

yes it can be done. I helped a buddy of mine do it on 6 port vert. but it's one of those things if you have to ask about it, you probably don't have the ability to do it.

Not being a dick. Its just a pretty involved project.

RotaryEvolution 10-03-13 12:54 PM

will only fit with an FD intake manifold, which won't bolt to an FC engine without lots of modification.

then you will have fitment issues with the turbo and notching the frame.

then you will need a standalone to be able to adjust the fuel that the turbos will need.

then you will need to upgrade the piss poor n/a fuel system because it will cap out at about 200whp leaving you with a blown engine even if it makes it to 5psi.

then there is no rear turbo oil drain on the FC block, so you'd have to modify a drain into the oil pan.


stop listening to people who say "dude, that turbo will fit your car, it'll rip and should bolt right on." yes, the turbos and manifold will fit without an intake manifold on it, and nothing else on just the turbos themselves.

is all that worth it when an FC turbo will fit with less headache? no.

Customisbetter 10-03-13 12:59 PM


Originally Posted by RotaryEvolution (Post 11588956)
yes, the turbos and manifold will fit without an intake manifold on it, and nothing else on just the turbos themselves.

Those will be the shortest runners ever. lol

RotaryEvolution 10-03-13 01:03 PM

plus the twins fall apart and have a lifespan of about 100k miles. why would you upgrade to the twins when you will need to change them out sooner or later? they aren't even really rebuildable because of the heat they have to tolerate.

oinesra 10-03-13 03:39 PM

Lol. Bolting the turbos on is the easy part.

Use a header flange as a spacer(with two gaskets obviously) the front compressor, and front secondary runner will need a little grinding for clearance.

This was 6port block with s4 turbo intake manifold.

The single biggest pain in the ass was the outlet Ypipe.

We even used an ebay 3rd gen down pipe as is.

But like I said, if you cant figure this out on your own, this project is kind of over your head.

SonicRaT 10-03-13 04:37 PM

2 Attachment(s)

Originally Posted by oinesra (Post 11589069)
Lol. Bolting the turbos on is the easy part.

Use a header flange as a spacer(with two gaskets obviously) the front compressor, and front secondary runner will need a little grinding for clearance.

This was 6port block with s4 turbo intake manifold.

The single biggest pain in the ass was the outlet Ypipe.

We even used an ebay 3rd gen down pipe as is.

But like I said, if you cant figure this out on your own, this project is kind of over your head.

This man speaks truth. S5 LIM will give you a good bit more clearance, but the waterpump will be a nightmare. I modified mine a bit, which wasn't all that difficult.

ETA: Attached are pictures of my "rebuild." Previously, I had used an FD LIM, however it constantly had leaking issues. So, I switched to a S5 LIM, as well as changed out a number of other things (bigger FMIC, fuel rails/lines/etc). I'll be documenting the "new" process in my build thread once I get around to it.

And yes, mine is still sequential.

Is it worth it? Absolutely not, unless you happened to have all of the parts laying around already, like I did. I parted another FD and had nearly everything left to do it, so it cost me next to nothing to build. It's hard to argue against free. The turbos were also known to be in good condition and didn't have a lot of miles, which was a considerable plus.

RotaryEvolution 10-04-13 05:50 PM

how did you go about draining the oil from the rear turbo?

j9fd3s 10-04-13 05:52 PM


Originally Posted by RotaryEvolution (Post 11589900)
how did you go about draining the oil from the rear turbo?

he's in AZ, he probably just left it open :P

SonicRaT 10-04-13 07:02 PM


Originally Posted by RotaryEvolution (Post 11589900)
how did you go about draining the oil from the rear turbo?

Now there's a loaded question that's sure to spawn an endless array of debate. Currently, I'm using a setup similar to Aaron's. I'm using a -10AN drain off the turbo into a -10AN fitting on the oil pan. Thus brings up the debate on if that line can overcome the hydraulic pressure of the oil level fast enough to displace the oil being pumped into it. I approached this by using a bit longer and more gradual drain than necessary, which both reduced the hydraulic pressure and increased the drain capacity before it would begin backing up. Consequently, I've never had a single issue with it (and I've used this drain setup for going on 10 years now).

jking 10-04-13 10:14 PM

As mentioned above.... It can be done if you use a exhaust flange as a spacer, ebay fd downpipe with 2" of clearance, fmic, mount the afm as a blow-thru(without standalone) and safc, the oil returns can be plumbed together then into front cover and there you go fd twins on a fc with the fc lim ...im doing it now to my sisters 6port

RotaryEvolution 10-05-13 07:49 PM

i could envision plumbing it to the oil pan but not routing it to the front cover, it's either going to have a major dip in the line or sit right on the scorching hot manifold with some major funky bends.

lastphaseofthis 10-05-13 08:20 PM

1 Attachment(s)
i was gonna make a thread for mine, after it's running, not sure if' i'll even care to finish now.. enjoy the pics.
I cut a spare FD manifold in half at the perfect angle to get the manifolds to clear. all bolted up, ran the oil lines, had an idea of how to run the twins seq, but i've lost interest... the advantages just don't matter to me any more. who needs 17 psi at 1500 rpm.. the engine can't use the boost to make huge power until 3500-4000 for most port styles, and a modern turbo achieves this and 400+hp.
https://scontent-a.xx.fbcdn.net/hpho...88270827_n.jpg
can't seem to find all the pix of the last time everything was installed... maybe that is what's on my dead camera..

to answer the original posters question. NO, YOU will not be able too. you will spend the value of your vert buying the turbo intake manifolds ecu, injectors, fuel pump, plus the cost of making the parts to retro fit it, like oil lines, intake piping, coolant. oil lines... yeah.

lastphaseofthis 01-05-16 06:03 PM

5 Attachment(s)

Originally Posted by jking (Post 11590088)
As mentioned above.... It can be done if you use a exhaust flange as a spacer, ebay fd downpipe with 2" of clearance, fmic, mount the afm as a blow-thru(without standalone) and safc, the oil returns can be plumbed together then into front cover and there you go fd twins on a fc with the fc lim ...im doing it now to my sisters 6port

no mine works as a draw thru.. 3 years later?https://www.rx7club.com/attachment.p...1&d=1452038397
https://www.rx7club.com/attachment.p...1&d=1452038397


i could envision plumbing it to the oil pan but not routing it to the front cover, it's either going to have a major dip in the line or sit right on the scorching hot manifold with some major funky bends.
well, first is my small oil drain, which i didn't finish because i didn't like it.
https://www.rx7club.com/attachment.p...1&d=1452038576

this is the final oil drain.

https://www.rx7club.com/attachment.p...1&d=1452038281https://www.rx7club.com/attachment.p...1&d=1452038281


i drove it around the block first time today.. 10 psi at 2k rpm in 2nd GEAR.. 10 as soon as you punch down. amazing. i might do a full thread after i get it transitioning and dyno'd at over 300.( 2 months away?) i should be installing my seq control rack and vacuum stuff later this week. right now its just rigged to boost on the primary. not sure what would happen if i tried to go high rpm. just choke out alot..


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