well again, if you allow the suspension to extend some before tightening all the control arm bolts down it can offset the sagging. If you have it fully extended and do that it will be jacked up in the rear like a hillbilly drag car.

 

im starting to think this part number is for a shinka spring which is shorter... if you have sport suspension on a 2006 shinka you probably look like you are on lowering springs stock.. im going to measure mine now

 

both sides front are @ 15" from center of wheel, both sides rear are @ 14.25" from center of wheel on stock springs 2006AT Shinka copper red

 

Shinka springs are the same as sport springs. It's the 2009+ rears that are different.

 

there were three different S1 spring sets; Standard, Sport, and the special Bilstein shocks. I thought the Shinka had the Bilstein shocks, which would not be the same as Sport.

 

no i have revalved 14mm shocks that are tokico NOT bilstein and a foam filled front subframe, and as mentioned above, lower rear springs factory

it looks like a newer part number spring thats mentioned here replaces two different older part number springs so maybe thats where the confusion is. i can only find one other thread mentioning the stock shinka IS in fact lower than other rx8 and i measured mine properly

i also have a clunk in the rear passenger side like some have mentioned maybe both shocks are blown out in the rear equally but im pretty sure springs are what set your height , correct?

the only bilstein factory shocks are the 40th AE and the r3 i think

 

Seller got back to me stating the part number was correct for my application (2006 Shinka). I was hoping they had more input than that, but im not surprised at their answer.
Im going to install these shorter springs and tighten up the control arm bushing bolts in the center loaded position as they should, and see where the car sits. If its too low, i guess ill be going for the hillbilly look at least partially. It will stress the bushings a bit, but hey. Compression rate and road performance pertaining to Michigan potholes will be another story. The new springs certainly look weaker but thats hardly scientific.

 

Installed the 1/2" shorter FE02-28-011 springs and indeed the car sat lower in the rear than the 60,000 mile oem springs, but only about 1/8" lower. Tells me the spring rate is indeed different from 2006 release. Suspension compliance on road seems to be the same. Tried a few times in 1 inch increments to load the bushings to raise it with little success, but i could not force myself to go radical. Strangely, through all my changes, the lower left side attitude of the car remained, even after deliberately jacking the left rear bushings. Its not as offset as Tamas's car, but noticeable. After messing with it all day, i left it alone. Will revisit soon, perhaps with spacers under the left side spring seat.

 

did you do one side at a time or have both sides up at the same time?

 

both sides at the same time so the torsion bar didnt mess me up

 

that’s not my experience, but **all of the bolts on the chassis bushings** have to loosened first and then after being fully raised with both rear tires off the ground, then all be bolted back down super tight so as to not slip. Because if they slip then it will just be lower again.

That assumes all the arm bushings are in good shape; not torn, worn out, etc. It might also need to make sure the bushing eyes aren’t seized or rusted to the mounting tabs because they have to be relaxed in the neutral position before being tightened down.

Because the rear suspension has a lot of travel and the bushings will resist against that when bolted down at the extreme position. The metal center eye in the bushing that the bolt passes through is bonded to the bushing, and the bushing is bonded to the outer metal ring that’s pressed into the arm.

So those don’t rotate freely if they’re tight enough to keep the metal center eye from slipping/moving. As the arm rotates with the suspension going up and down it creates resistance torsion within the bushing material. Kind of like small springs that resist the motion.