Performance suspension without relocation of rear springs

I think James did something like this to remain legal in NZ. I think it's somewhere in his build thread.

can you run replacement springs in the stock location for the rear? if so, consider 79-93 Mustang springs. I am currently running aftermarket "Ford racing "C" Springs" I am using the fronts from the kit, cut down and under the rear of my car, with limit straps as well for safety. damn effective! 600+lb setup!

I've thought about that too, but I would rather do some kind of standard size coil spring so I can perform height adjustment (corner balancing) as well as switch spring rates for different tires and track surfaces.

I'll check James' thread as a refresher.

if you could put a threaded section under them, would work perfect! (bolt a threaded section base to the control arm) Im interested in following this progress!

I run the same size coils and adjusters as you weld on the front from grounds control. They fit over the centering bump on the control arm and the body. If you use 89-93 foxbody shocks also you don't even need limiting straps if you don't adjust too low. This is my exact setup.

Aaaactually you should talk to russ about this…

You can continue to use your coilover without the spring and collars, then just install the correct height spring over the hump -- I expect same rate should work, or go +10%

cheers DZ yes indeeded I did.

I will edit this post with pictures soon.

So Basically whats happening here is a modification of Another idea ive seen on Z31P which used a pivot for the top spring hat.

The Purpose of this Modification is to use 2.5" coilover springs And to keep the spring in vertical compression during the swing of the semi trailing arm.

The Tit on the RCA is removed and trimmed up with a 3mm plate cut to shape and tig welded Inside & outside to provide a solid base to work with. From here I used Coilover top hats from something like Maxima or Cefiro or S13 rear suspension to give me the stainless steel base with the spherical bearing so i Could drop it down into the plate on the STA.

From here you cut a hole to locate the bearing block into the STA so its concentric and captive. The screws are there to hold it in and basically stop it clonking around.

The last piece required is a coil over spring top hat to be mounted through the spherical bearing in the block, this gives the movement you need to keep the spring in a straight line during compression.

The Threaded adjusters are not alloy they are something like 3 or 4mm steel, and they have a 10mm thick shoulder welded onto the top to provide a base for it to seat onto the chassis.

I have run this for 2 years with 8k springs which is something like the equivalent of 6.5 K if the spring was mounted the same as a full coil over shock.


I must note I used RUSS84 NA's calucations on moments and spring rates to work out the ride frequency. My car is very stable on a VERY rough road and the setup has proven itself on the street and a couple track days.

I have nothing to add, other than my general excitement to see some actual threads on suspension performance

You know me Adam, just doing shit with no special tools. Just a hacksaw and a file, Its worth pointing out that lot was done over 2 years ago.

I really don't care if happened a decade ago. Just like seeing conversation being generated.

A lot of my multilink suspension is out of my 85t getting some upgraded parts (HLSD, upgraded axles, driveshaft, 30a, ect…) but primarily due to identifying what the hell is causing the vibrations. Once I find the issue or set of issues and satisfied with the outcome I will post up. I like have answers where possible prior to posting issues.

But I digress