OK I'm tired of reading so I'm gonna ask in a new thread.

I know you can do a front end Lower sub frame swap from a 2nd Gen RX-7 to get better over all suspension parts bigger front disc brakes and rack and pinion along with being able to lower the engine center of gravity.

I know the rear of 2nd Gens are Independent Rear Suspension (IRS) and 1st gens are solid live axle. Now please be aware that I AM NOT ASKING CAN I MAKE MY 1st GEN IRS!

Rather what/where is the weak link in the rear suspension that doesn't allow for a strut surrounded by a spring setup? Is it the upper perch of the strut towers not strong enough or is it something else?

What do i need to modify or reinforce to make a coilover or like suspension work on a first Gen?

I know RE-Speed has a GREAT rear coil spring adjuster but this isn't what I'm looking for.

Any help or guidance is always greatly appreciated.

 

The rear upper spring perch is probably strong enough to support a strut/spring combo. However, there isn't enough travel length to accommodate it. There's also no way to attach the lower end of said combo due to the lower spring perch sitting directly on top of the axle. It may be possible to move said combo to the current shock position, but the mounting flanges on the axle aren't strong enough and moving them there, even with re-enforcement, would change the suspension dynamics.

 

Ok that's a big help.

 

OK So i'm wondering now (after looking at the rear end geometry) if maybe a weld on piece could be made to keep the stock location the same just place it under the coilover...
Like a sleeve/boot for the coilover to sit in?

I'm thinking about drawing this up for my Mechanical Drawing class final project and sending it to the school's machine shop to be made.

 

Draw away, but my guess is there isn't enough travel distance between the axle and spring tower. Reinforcing the shock mounts may work however.

 

My plan is shock mounts.