S13 Rear Coilover Conversion

[joe99549]

Hey guys,

I'm currently doing a s13 coilover swap on my 1984 Celica GTS. I was able to find a decent amount of info on the front swap, but not too much on the rear. From what I can tell, the top hats will need to be removed and a sleeve needs to be pressed into the bottom coilover mount to tighten the hole. Does anybody have an idea of what it takes or know of a thread that has said info?

[Teranfirbt]

After looking at some pictures of S13 rear suspensions, I'd say you've signed up for a bit more than you bargained for. The rear suspension layout between an RA65 and a S13 is fundamentally different. The spring and shock points in your Celica are different, with different levels of floor pan reinforcement to match. You will probably want to add sheet metal to the rear floor pan to prevent the coilover from punching through the shock mounting point, since it isn't particularly thick. The shock point is only made to see a max of 100lbs or so, where the spring perch is made to handle 1000lbs or more. There is legend of Gary M building a rear coilover setup, but it looks like the site with information is gone

[joe99549]

After looking at some pictures of S13 rear suspensions, I'd say you've signed up for a bit more than you bargained for. The rear suspension layout between an RA65 and a S13 is fundamentally different. The spring and shock points in your Celica are different, with different levels of floor pan reinforcement to match. You will probably want to add sheet metal to the rear floor pan to prevent the coilover from punching through the shock mounting point, since it isn't particularly thick. The shock point is only made to see a max of 100lbs or so, where the spring perch is made to handle 1000lbs or more. There is legend of Gary M building a rear coilover setup, but it looks like the site with information is gone

Yeah, I've seen a decent amount of arguing over at celicasupra over the strength of the shock towers. I've seen some of those guys do some bracing to strengthen the shock towers for a coilover setup. I figure to be safe I can separate the coilover spring/shock like this guy.

https://www.celicasupra.com/threads/a-few-new-photos-of-my-ma61.52492/page-3


Then use these springs.

https://raptorracing.ca/toyota-mkii-supra/mk2-suspension/dobinson-mk2-300lb-rear-lowering-springs?zenid=0eea560af5e12ebe239afa1c97d439b5


That would keep the rear like the oem design and also allow me to use the 8k springs from my rear coilovers in the front. Any thoughts?

Thanks for the help!

[Teranfirbt]

That'll definitely be easier than bulking up the floor pan 

[joe99549]

Ah come on... What's a little fabrication gonna do to hurt anybody. Sometimes the doing things the hard way works out just fine!