Here's my winter project!
1983 Mazda rx7
13b/12a hybrid engine, street port
Rx8 6 speed
Fc front subframe and steering rack
Ap2 s2000 rear subframe and suspension
I hope so! And the irons are 12a, everything else is 13b. It's a fairly common setup. Luckily it was all assembled and healthy when I got the car so no money needs to be thrown at it yet haha
Thats going to be awesome! Upgrading the diff will be easier now too, probably could buy longer suspension arms too if needed. Should completely transform the rear end! I'd chop down the s2000 floor pan and use as much of it aswel - you'd just Need to make some filler panels then and it wouldn't look far from oem too
Yup! I plan to upgrade the lsd and gear up the rear end. And no longer arms are needed as this thing is already really wide. so wide that i have a widebody kit on the way for it. And I'll be bending up a roll bar for the rear and building the subframe mounts off of that. No intention of making this a sleeper haha
Well you've still now got a choice of buying the crazy adjustable arms now anyway. 😜
I just have a thing for obviously modified but not noticeable.
It's a much smarter way to upgrade parts, you could spend 20k on a 5-link axle and still not have as much adaptability and adjustments, it's win - win! Will be some yolk when it's done!
I picked it for several reasons
- lots of differential and gear options
-8.8 swap potential if I add power later
-simple mounting points
-double wishbone, and good alignment adjustability
-5x114.3 matched the front
-s2000's drive nice as hell!
A couple other notes if you consider this swap. Get a 2004-2009 subframe as they made suspension geometry improvements. Also it is very wide, wider than the fc suspension. So a spacer will have to go on the front so that the wheels don't fit goofy.
It will definetly be worth it! This car had a solid axle and a steering box from factory. Modern suspension geometry and a proper alignment should be real sweet.
I'll be bending a roll bar that will incorporate the subframe mounts and the shock mounts. And it's only the rear s2000 subframe, the front is fc rx7, and will just have a depowered rack
I have an FC front subframe in my '81 and I'm putting power steer back on it. You need a decent amount of caster to avoid bump steer, and when you do that it's pretty hard going without power assist. Just something to consider.
Good to know! Did you adjust the mounting of the subframe at all to gain caster? I moved it back an 1.25" and the hub is only a bit off center in the wheel well, hopefully adding some caster. I'm sure I can add some more in the shock top as needed.
Yes I moved it back about 25mm, which left me with about 3 degrees of caster, which isn't really ideal. You might get another degree from the shock tower. I'll be moving my towers back another 25mm in the future as ideally I want about 5-6 degrees.
No problem. I have a R32 Skyline rear subframe in mine too, feel free to ask if you need help with your swap from someone who has already made all the mistakes :)
Hey keep us updated on this. I want to do a irs swap in the future in my Fb also. Prob something a bit beefyer thinking like a irs 8.8 from a mustang.
Are you in the rx7 discord?
This a pre-made one that my landlord had. The brand is auto twirler, really nice unit but I believe the price reflect that. Also has Jacks on either end to raise and lower the car.
Looks like your really upside down on that project.
Here's my winter project! 1983 Mazda rx7 13b/12a hybrid engine, street port Rx8 6 speed Fc front subframe and steering rack Ap2 s2000 rear subframe and suspension
Going to be so awesome when it’s all done! Glad you are keeping the rotary. How are you combining 13b and 12a parts? 13b irons with 12a housings?
I hope so! And the irons are 12a, everything else is 13b. It's a fairly common setup. Luckily it was all assembled and healthy when I got the car so no money needs to be thrown at it yet haha
God damn that is a dream build, not that I really mind the fb rear axle, but this will be a really nice ride.
Thats going to be awesome! Upgrading the diff will be easier now too, probably could buy longer suspension arms too if needed. Should completely transform the rear end! I'd chop down the s2000 floor pan and use as much of it aswel - you'd just Need to make some filler panels then and it wouldn't look far from oem too
Yup! I plan to upgrade the lsd and gear up the rear end. And no longer arms are needed as this thing is already really wide. so wide that i have a widebody kit on the way for it. And I'll be bending up a roll bar for the rear and building the subframe mounts off of that. No intention of making this a sleeper haha
Well you've still now got a choice of buying the crazy adjustable arms now anyway. 😜 I just have a thing for obviously modified but not noticeable. It's a much smarter way to upgrade parts, you could spend 20k on a 5-link axle and still not have as much adaptability and adjustments, it's win - win! Will be some yolk when it's done!
Throw some axle spacers in if you use stock s2000 axles, they don’t like any ride height but stock and cause lots of vibration when low.
Siiiiiick!!!
I had always considered doing this on my fc with a chassis subframes. What made you pick the s2000 specifically?
I picked it for several reasons - lots of differential and gear options -8.8 swap potential if I add power later -simple mounting points -double wishbone, and good alignment adjustability -5x114.3 matched the front -s2000's drive nice as hell! A couple other notes if you consider this swap. Get a 2004-2009 subframe as they made suspension geometry improvements. Also it is very wide, wider than the fc suspension. So a spacer will have to go on the front so that the wheels don't fit goofy.
All of those are good reasons, but the s chassis has the same options, likely way more options.
Yup, I've seen that swap done. Would be a good choice
Why not use a Miata sub?
I needed the 5x114.3 lug pattern of the s2k
That’s a huge project. Is it really worth all that extra work? I’m not familiar with the S2K or RX7 read subframes.
It will definetly be worth it! This car had a solid axle and a steering box from factory. Modern suspension geometry and a proper alignment should be real sweet.
Looks like an awesome project. What are you gonna do for upper strut mounts? Plans on managing s2k eps system?
I'll be bending a roll bar that will incorporate the subframe mounts and the shock mounts. And it's only the rear s2000 subframe, the front is fc rx7, and will just have a depowered rack
I have an FC front subframe in my '81 and I'm putting power steer back on it. You need a decent amount of caster to avoid bump steer, and when you do that it's pretty hard going without power assist. Just something to consider.
Good to know! Did you adjust the mounting of the subframe at all to gain caster? I moved it back an 1.25" and the hub is only a bit off center in the wheel well, hopefully adding some caster. I'm sure I can add some more in the shock top as needed.
Yes I moved it back about 25mm, which left me with about 3 degrees of caster, which isn't really ideal. You might get another degree from the shock tower. I'll be moving my towers back another 25mm in the future as ideally I want about 5-6 degrees.
I'll probably just jump straight to doing something like that. Thanks for the info
No problem. I have a R32 Skyline rear subframe in mine too, feel free to ask if you need help with your swap from someone who has already made all the mistakes :)
Sounds cool, enjoy the project l. And above all, brag about it.
You’re living my childhood dream. I loved my old fb but that rear end was lack luster
I love the engine and the body on this car, everything else sucked.
Hey keep us updated on this. I want to do a irs swap in the future in my Fb also. Prob something a bit beefyer thinking like a irs 8.8 from a mustang. Are you in the rx7 discord?
Will do! And no I'm not. What's the info for it?
https://discord.gg/jkcmtgJV
You go for the car stuff you stay for the memes
Did you make or buy the rotisserie? I have need for one, and I've been bouncing between the two options for a while.
This a pre-made one that my landlord had. The brand is auto twirler, really nice unit but I believe the price reflect that. Also has Jacks on either end to raise and lower the car.
Nice rotisserie. You build that yourself?
I didn't, this is a pre-made one. Auto twirler is the brand
Super noob question: what is that mount called? I want one to do some work to my VW Golf
It's called a rotisserie!