Rx8: a new suspension

I admit, sometimes I am lazy and I forget about things. In my case I forgot about a tiny leak in my front left strut, promising myself and my car I will take care of it soon. That was in summer. A few months later (December…) my dear Rx8 gave me a very abrupt reminder: My left suspension gave in, and my car started leaning left…

Because I am not a complete idiot, though, I already had done my research and chosen a new suspension: The Bilstein B12 Pro-Kit. The Bilstein B12 markets itself as a both comfortable and sporty suspension upgrade. It is easy to install, shocks and springs are already perfectly fitted to each other and it even comes with TÜV-certification! The kit also promises to lower your ride by up to 50mm while keeping your original suspension geometry and to give a firmer and more precise handling on the streets. It sounded perfect to me!

Before I walk you through my install, let me be very clear about this type of modification: DO NOT attempt to do this at home or alone. That would be very stupid and can be dangerous. Please ask someone to help you and go to a proper car shop to do your work! Without help or the proper tools, you risk damaging your car, the suspension and even seriously hurt yourself!

I myself went to my favorite car place: “Maach et selwer “. They offer a vast and clean workspace, two lifts and a large assortment of specialized tools for your projects. You can even order your parts there or leave the old parts, and they‘ll recycle them for you!

So let‘s get started with the install. I did my research (the Rx8 workshop book has all the technical data you need), asked friends to help and had all the required parts. What could possibly go wrong? Not too much.

I recommend doing the suspension according to each axle. So we started at the front, where my suspension was already damaged.

Step 1: Front Suspension removal

We removed the strut bar from the engine bay, removed the strut brace and removed the bolts connecting the front suspension to the chassis. After this, we raised the car and took off the front wheels. After, we sprayed the lower bolt of the headlight leveler arm and both sides of the lower suspension bolt for easier removal. Let the lubricant work its magic and then remove the lower bolt of the leveling arm with two wrenches and tuck it away, so you don’t risk damaging it. Also tuck away the break line by unscrewing the bolt connecting it to the triangular front arm. Do the same for the front ABS line.

Practical tip: whenever you can, you should put bolts back on so you don’t risk loosing it (and your mind while searching for it…).

Now comes the part where you are happy to have help: you need to loosen the bolts of the upper suspension arm to make space to get everything out. First though, loosen the lower suspension bolt and take it out. It took one of my friends to hold a wrench on one side and me unscrewing on the other side to get it done. They are pretty tight and you need to counter the unscrewing movement, or you’ll get nowhere… Now loosen the bolts on the arm and use a pry bar to get it out so you’ll have the necessary space to move the suspension out. If you have trouble getting these bolts loose, you can jack up the whole suspension a bit to lessen the tension. We actually did that too.

And finally, the wiggle game begins. While one person pulls down on the lower suspension arm, another gets to wiggle on the suspension and take it out without hitting anything around. Such fun! Be really careful when taking it out and have patience. The Rx8 is tight… After getting the old suspension out, secure the arm with cable ties to avoid it dropping out.

Repeat the process for the other side.

After the first set was out, we were happy people but realized, we were not the smartest. In hindsight, we should have marked all the parts we took out with “left” and “right”, because we were reusing parts of the old suspension, and you really really should remember to put stuff back in the right places… Luckily someone kept track and we marked them in retrospect with a chalk marker.

Step 2: Front suspension assembly and install

The Bilstein B12 came with both springs and struts, but we had to reuse the upper spring seat (the black triangular thingy on top of the suspension where the bolts are located) from the old suspension because, for the life of me, I could not find a new one by itself. For taking apart the springs from the strut, please use a proper spring compressor and do not endanger yourself with any other method! Best are the ones where you can firmly clamp the springs in and use a wrench on top to loosen or tighten. So clamp your suspension in tight, make very - very sure it is secured safely and only then loosen the top bolt. At the same time have someone hold on to the suspension because it can just fall after you loosen the upper bolt. Clean up the upper part with some Isopropyl (99% cleaning alcohol) and put them safely away.

Then some more fun: putting together the new suspension! After assembling all the parts (please use new rubber bushings and the parts included with your new suspension!), secure the new set in the spring compressor and slowly tighten the upper bolt. To protect the threading, use a tiny bit of installation paste (Liqui Moly is awesome) before putting on the bolt. Use a hex key to secure the bolt while going at it, or you won‘t be able to tighten it enough! I‘ll talk some more about that particular issue in another post…

After assembling and tightening, you can put the shock and strut back in the way it came out. Secure back all the bolts and repeat for the other side. Easy! BUT careful, you‘re not done yet! You now need to put down the car and tighten the upper suspension bolt some more for a perfect fit.

Step 3: Rear suspension removal and install

For the rear suspension, you first need to remove your inner trunk covers to access the suspension bolts. Take out the round plastic clips (and best have some spare because some WILL break…) and take of the side carpet parts. Then take off the outer bolts on the golden strutholder plate, then the inner ones and take the plate off. Put the car back up and remove the wheels. Make space again by placing the ABS line aside and loosen the bolts on the upper suspension arm. Now remove the lower bolt of the suspension like the front one, take it out and maybe use a pry bar to push out the lower part of the suspension. Pull the sides of the arm slightly aside, then remove the last bolt holding the suspension in (located on the spring seat, the black tube on top of the suspension) and voilà. Shock and spring coming out after some more wiggling. Disassemble the old spring from the strut on the spring compressor (see Step 2), assemble your new set and put it back in place! Put back all the bolts and be done!

After the install, we checked the overall car height and as promised, the new suspension dropped my baby by about 25mm! I am now officially scrapelevel in my garage when driving down…

Thanks for reading and if you have any questions or comments, feel free to contact me!