S13 Rear Subframe

Alright, I've looked around in the threads quite a bit and I've seen that people have adapted S13 rear subframes to the S12.  I have not however seen a write up (dont blame them, what a PITA haha) nor have I really seen anyone who has really dont it on here.  


These pictures make it look easy...TOO easy, but I'm curious what is really involved though.  These were taken from the RaceSilvia.com site and I know its a lot of welding and cutting..but these pics look like there wasnt much welding and cutting...maybe I'm just not seeing it...
I'm not trying to set a flame war here, but it would be nice to have all info in order to do this swap in one place.
Would you need different rear 4 links? Would rear z32 brakes be easier to install?  Seems like you would need S13 rear coils, how could you get that to work?  What benefits would it hold?  Would rear suspension be easier to set up?  What S13 parts could be used after this?  I'm sure I'm not the only one with these types of questions...lets see how many can get answered.

i think if it were easy or i had tie to flip my 12 over on its shell it would be done alot more by alot more members. but i two would like to know the dificulty involved. but converting to a ka24de and s13 front and now a s13 rear suspension setup might as well buy a damn s13. i like s13's but i love my s12

THATS the reason, it may be an S13 underneath, but its still the S12...and 240s are hot around here anyway...drive one with an exhaust, pulled over immediatly (not really, but you get the idea) With the S12 I have no doubt I could ride with a high boosted SR and get away with it saying "my car came turbo from the factory"...
Point is, I love this car more then I did my S13, I SOLD my S13 for that reason...and I dont doubt all of us would like to have this info available to us

There's quite a bit of fabbing involved, the pics don't quite do it justice.  One of the guys on here, RB25sx-SLPR, did some documentation when he did this mod, but really as he said, almost all of it was custom and figured out at the time of installation.  Look for the details in the Hybrid forum. Unless you are going balls-out on a track, the advantage of the S13 over the S12 irs wouldn't push me over the edge to do it, but the S13 unit is nice because it maintains much more proper wheel alignment thru its path of travel vs the S12 unit.  The S12 irs can be modded to account for some of this, but the design is just so much different, the S13 will always be a bit on top.  Personally, it weighs more and is more complex than our unit, and the performance difference vs a modded S12 irs doesn't justify the work to fit it properly, in my mind, but if it was something you would like to try its quite the commitment.  I -think- the strut towers would need to take the weight of the car, as the S13 has coil-over-strut type of setup for the rear, vs our independent shock and spring setup.

I am re-doing mine in the next year or so because I do not trust my rear mounting points whatsoever.

Essentially, there is alot of drilling and welding involved. You have to completely cut out all of the upper spring perch and shock mount and create your own tower. I created a jig (documented in my build thread) and used a friends S13 to center the top of the shock mount. I would advise using the factory S12 mounts and 'extending' the S13 subframe to meet up with the mounts and welding the two together. This move alone took at least 10 hours of measurement and mock up.

A couple tips i'd suggest to speed things up:

-Have you crossmember cleaned and ready to go with the diff uninstalled.
-Use a ~6" diameter pipe which has been capped to create shocktower. I made mine from a jigsaw collection of 1/8" plate steel and it is nartsy looking.
-Find an S13 and create the jigs beforehand.
-Have you shocks/coilovers ready to go

I would highly suggest creating a mount for the rearmost bushings on the S13 subframe BEFORE trying to put it in place. It lines up perfectly with a crossmember that spans the trunk and rather than DRILLING AND REINFORCING (through the trunk) like I did, I would suggest gussetting the pre-fabbed mount onto the crossmember and creating a nice, flat, surface for the subframe to butt up against.

-Dan

200sxkitcarThere's quite a bit of fabbing involved, the pics don't quite do it justice.  One of the guys on here, RB25sx-SLPR, did some documentation when he did this mod, but really as he said, almost all of it was custom and figured out at the time of installation.  Look for the details in the Hybrid forum. Unless you are going balls-out on a track, the advantage of the S13 over the S12 irs wouldn't push me over the edge to do it, but the S13 unit is nice because it maintains much more proper wheel alignment thru its path of travel vs the S12 unit.  The S12 irs can be modded to account for some of this, but the design is just so much different, the S13 will always be a bit on top.  Personally, it weighs more and is more complex than our unit, and the performance difference vs a modded S12 irs doesn't justify the work to fit it properly, in my mind, but if it was something you would like to try its quite the commitment.  I -think- the strut towers would need to take the weight of the car, as the S13 has coil-over-strut type of setup for the rear, vs our independent shock and spring setup.

"create the jig" lol yeah when someone says that, it's either not worth the countless $$$$ for a shop to do it, and you better have decent fab skills of your own.

Hey Dan let me ask you the all-important question: If you were at the beginning, would you do it again?

Arro"create the jig" lol yeah when someone says that, it's either not worth the countless $$$$ for a shop to do it, and you better have decent fab skills of your own.

Hey Dan let me ask you the all-important question: If you were at the beginning, would you do it again?

So then would you recommend to others to do it? Or do you think it's worth it? That's what I'm asking. You're the one who did it

The benefits do not outweigh the work, only do this if you are seeking something unique, and want a challenge.

-Dan

So basically you're not recommending it. And you're the guy who did it personally. That's what I was looking for

so because of the hard work you do recomend doing it?
what about the benefit or having the multi link setup and being able to adjust the suspension
aswell with having a bit more diff options?
i know old thread just wondering

Sterling is working on a simpler solution to this that would allow us to run with S13 multi-link rear suspension, if it works, it would mean two small changes and the entire assembly would bolt on. If it works.

if you guys need anything for that, ive got an entire S13 and an notch s12 that are jy bound in the next few weeks

subframe is comming out of the s13, not sure about the s12 yet

He has everything he needs.

But until he finds out, the way it was done before by the previous guy is apparently NOT recommended by the same guy who did it. So for now, the answer is it is not a good idea until someone figures out a simpler way. If it even exists.

im taking on this challenge rite now.. and i definintely would not do it agen if i could turn back....which u clearly cant.. after u start modding.. lots of cutting and welding..... im sure u could modify your diff to carry different ring gears  by modding the pinion sum wut and lsd's fit easier than swappin a subframe in my opinion.