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-   Other Engine Conversions - non V-8 (https://www.rx7club.com/other-engine-conversions-non-v-8-118/)
-   -   Rb20det ==> Fc3s (https://www.rx7club.com/other-engine-conversions-non-v-8-118/rb20det-%3D%3D-fc3s-767283/)

fcdrifter13 10-31-08 10:37 PM


Originally Posted by YoshiFC3S (Post 8328669)
RB20 is fkn' trash. If you put in that POS you are insulting the FC.

At the very least, put in a damn RB25. You can make 400rwhp reliability, just by having ARP head-bolts, a steel head-gasket, and of course the right size turbo & tuning. Power FC works great with the RB25. My brother made 443rwhp/391tq on his RB25 in his Datsun 280Z. But that much power is really pushing it. He ended up going through a few motors, until he decided to give up on RB's in general.

So yeah...

RB20 = NO

RB25 = Sure, will make a safe and reliable ~350+ hp.

RB26 = If you're rich

SR20 = Good luck trying to make anything beyond 350rwhp reliably. Lame.

This post is made of fucking fail and lose. I have had a RB24(without googling can you figure out just what that is if not please GTFO) and it was a very strong and reliable engine. Ever had a single problem out of it and the bit to piece it together were cheap enough. And i lol at 400hp reliably, surly you meant from and rb20 and not a 25, the RB25 can handle a hair more than 600 and be reliable with a couple of simple modifications to the bottom end and oiling system.

Miata_mx5 11-01-08 04:23 PM

I would rather put a Toyota powered 1jz-gte in an Rx7 vs any Nissan RB20, 25, 24 Hybrid motor.

Zerkster 11-16-08 11:38 PM

Most poeople over react at RB26 swaps, they really are not that bad if you know what your doing. I succesfully swapped it into an S13. Granted they sell mounts and driveshafts, but the main idea is still there.

240kat 11-18-08 12:56 PM

i thought about this swap for a while.

good luck finding parts stateside, as far as cams and manifolds go..you'll either pay premium dollar for things from Austraila or you'll buy a welder. The 25 is a better deal, by a lot. Even though you have to shell out an extra (lets be generous) $1000 in the beginning, you won't have to make any power mods to hit 300rwhp.

Oh, and lest we forget the torque curve of the rb20..and the exhaust note..yuck. It sounds like a probe GT.

As far as SR reliability, 350rwhp is pretty conservative..id start putting reliability concerns on the table at 400-420. No amount of engineering can promise an engine in the hands of an idiot, though.

Evil Yetti 11-24-08 05:43 AM

Your rb swap seems intriguing... Im working on a 2jz swap on my 90 FC and this is the second closest swap Ive seen other than a 1jz swap on cardomain.. lemme know how it goes.

veedubbed 12-15-08 11:19 PM

I went over and looked at the car for the first time in a month today, I really want to get back on it, just no time at all recently. It is for sale if anyone is interested. If not, I may sell the swap and the shell separate and just eat my losses. Even if I just devote all my spare time into finishing the car, I will never have time to drive it. I really just need to cut back to just 1 car and 0 projects for now.

deuce_fc 12-23-08 10:27 PM

has any one done this swap or a rb25??? just wondering how much it will cost.

rXzach93fd 12-24-08 12:09 AM


Originally Posted by deuce_fc (Post 8821855)
has any one done this swap or a rb25??? just wondering how much it will cost.

im just about done with my rb25 swap, yea dont do it it is very expensive, i would have done ls1 if i could do it all over.....

deuce_fc 12-24-08 01:01 PM


Originally Posted by rXzach93fd (Post 8822129)
im just about done with my rb25 swap, yea dont do it it is very expensive, i would have done ls1 if i could do it all over.....

if you dont mind could you tell me how much you spent on it??? compared to a ls1.

darkprince134 12-30-08 04:40 AM

rb25s arent cheap to start with

rXzach93fd 12-30-08 10:51 AM


Originally Posted by deuce_fc (Post 8823078)
if you dont mind could you tell me how much you spent on it??? compared to a ls1.

i imagine they both would be around the same price, ls1 would be a little cheaper, the main reasons I would do ls1 over rb25 if i could do it again would be the fact that you can buy a bolt on kit for it, it makes the same power without dealing with turbo issues, a LOT easier to find parts....it took my like a month to find a crank bolt for an rb25

semperdrift 10-05-09 02:07 PM


Originally Posted by fcdrifter13 (Post 8685214)
This post is made of fucking fail and lose. I have had a RB24(without googling can you figure out just what that is if not please GTFO) and it was a very strong and reliable engine. Ever had a single problem out of it and the bit to piece it together were cheap enough. And i lol at 400hp reliably, surly you meant from and rb20 and not a 25, the RB25 can handle a hair more than 600 and be reliable with a couple of simple modifications to the bottom end and oiling system.

> I'm about to have this swap done to my FC while I deploy overseas...again, and I'm surprised by how many people don't realize how awesome an RB20DET can be. I've been poking my head in some Australian Forums and those mofos have been getting away with like 350-380hp safely with fairly inexpensive and easy mods done. Recently my buddy who's doing the swap mentioned the
RB24 idea. As far as I'm concerned the RB's just another motor that with the right knowhow it's good to go.

semperdrift 10-05-09 02:15 PM


Originally Posted by YoshiFC3S (Post 8328669)
RB20 is fkn' trash. If you put in that POS you are insulting the FC.

At the very least, put in a damn RB25. You can make 400rwhp reliability, just by having ARP head-bolts, a steel head-gasket, and of course the right size turbo & tuning. Power FC works great with the RB25. My brother made 443rwhp/391tq on his RB25 in his Datsun 280Z. But that much power is really pushing it. He ended up going through a few motors, until he decided to give up on RB's in general.

So yeah...

RB20 = NO

RB25 = Sure, will make a safe and reliable ~350+ hp.

RB26 = If you're rich

SR20 = Good luck trying to make anything beyond 350rwhp reliably. Lame.

> Read this part a little late, but you may want to check out some Australian Forums. They're making pretty good and reliable power with RB20's down there.

BoostedBseries 10-08-09 06:27 PM

considering a similar swap instead of my fe3, just wondering if anyone has yet to complete one with a stock hood?

eastreetmotorsports 08-16-10 07:59 PM

????
 
so what happen to the swap project?

NoPistons! 09-20-10 09:00 PM

Anyone who has interest in the swap may or may not see me complete one this winter. I'm growing more and more tired fighting issues with my engine bay and 20 year old harness. Out with the money pit, in with something i can fucking drive everyday without worrying about getting stuck and calling a tow truck...

NoPistons! 10-11-10 07:32 PM

I should be getting my rb to tear down and build up here in the next few months.

Reliability issues are pretty much solved when you do the following to these:

Non-ceramic turbo
1.5 mil tomei oil passage restrictors
Aftermarket harmonic balancer
Tomei or raw brokerage crank collar
Proper catch can set up
Baffled oil pan (if you're going rear sump anyway, might as well do this to ur pan at the same time. Piano hinges and thin gauge ss isn't expensive. You can borrow a 110v FLUX CORE welder and do it yourself in a few hours. RB pans are stamped steel meaning no need to bust out the aluminum welder or outsource fab.

The motor is fucking cheap and if you leave the boost stock and rev limit stock you COULD have it turnkey for around $2000. You dont need the harmonics or crank work done if you keep output near stock and stay off the limiter but for around $1000 more you can get on the limiter and pop the boost without worries of destroying your oil pump and/or spinning bearings.

ByeByeSti 10-11-10 08:36 PM

or for those looking to swap in an rb25 into an fd. i could sell my entire set swap.. everything you need...
or will trade for a 13b set up++

Nightshade_fc3s 02-27-11 10:08 PM

Hey my name is chase, I am currently debating on a swap of an Rb20det. my brother has an rb20det powered 240sx, and has now bought a Toyota Supra (2jz) so he decided to give me his 240sx as a gift for my birthday. But i'm not a big fan of the 240sx but I love skylines and rx7s so I thought hey why not give it a shot.. So i wanted to swap the engine into a 91 fc3s because it looks very unique to me. So I have a question, is it hard to put the motor into the fc? And were you able to find all the parts needed in order to drop the rb in? Also does anyone kno where to find a custom rear sump for this swap? Really need help on this, because I want to do it right!

Thanks in advance for any suggestions :D

NoPistons! 03-04-11 01:04 AM

There are a couple of places that have rear sump kit available for rb20. The shifter hole lines up.


You will need to wire this up yourself or have someone else do it.

You will need custom mounts and driveshaft. You will also need to see what needs to be done snaking your downpipe around past steering bits, the brake and clutch bits.... Custom clutch line. Modified throttle cable perhaps? Ofcourse a custom driveshaft BUT if you have an rb shaft (iirc, usdm 240sx shaft works) and an rx7 shaft, any competent shop should be able to join the two to work for you.

It's not a DIFFICULT swap but it can be overwhelming and involved if you dont take your time, sit down and manage exactly what needs to be done. Make phonecalls...etc.

I passed up on my rb deal (and it was an epic deal too) in favor of a stronger engine with more potential. Every bit as hard as the rb20 swap but zero reliability modding needed for what i'd like to do with it. :) 400hp rb20 is a disaster waiting to happen. I COULD have been happy with 250-300 but still. I like to rev and beat the dogshit out of my vehicles and the rb simply wasn't budget friendly enough to work with. not to mention sourcing off the shelf replacement parts at my local auto part stores.....

Doesn't change the fact it's STILL a cool engine and could be very much at home in an rx7.


Tip? Look at OTHER in depth extreme engine swapping builds and use that to inspire you. You'll have the blinders on looking in one place otherwise and it makes potentially good things invisible to you. Honestly, the less time i spent away from rx7club, the more i learned about rx7's. Most of these people DO NOT think outside of the box.....or maybe they do for a month and conform to what the rest of what some people on the internet want them to be. Dont be THAT guy.

Rear sump, driveshaft and wiring are going to probably be your main focal points getting started.

Motor and transmission mounts are fairly easy if you measure, check, check, double check. I think you'll be fine. Right now you should ask yourself "Do i want an rb20 rx7 or not".

http://www.enjukuracing.com/greddy-r...on-p-9157.html

http://www.enjukuracing.com/rb25det-...p-p-10443.html

If you're baller, you'll be sourcing off the shelf. If you're frugal, you'll be doing mockups and measurments and having your own stuff made from scratch. OEM rb pan is stamped steel. You CAN cut the pan down at the flange, flip it, chop, weld and do the same to the pickup and have your own rear sump setup cheap.

Joshuam 10-24-20 04:30 PM


Originally Posted by R.P.M. (Post 8398031)
I had my engine set back further than that, it was pretty much touching the firewall :)

How did you do the engine mounts?


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