First and foremost I just wanted to say I have been a long time lurker soaking up information throughout the forums and been following the 350Z shock thread closely. I just wanted to join to say this project is not a bust and give credit where due to Wile E. I chose Bilstein B8's because they are basically the go to shock for maintaining on street manners whilst being significant upgrade over the stock stuff on multiple platforms (a favorite stock replacement for the S550), it's monotube design, and most importantly the fact it does not have the external stop ring that keeps a MN12 top hat from working so I was able to utilize the MN12 top hat on the 350Z shock with 0 modification to the tophat. I did not have to trim the spring perch as the 350Z LO-Suspension 1" drop springs I chose fit the perches perfectly centered. I did not cut my shocks down and used them as is height-wise. From what I understand from 350Z guys is that the B8 and B6 have similar stiffness but the B8's are engineered for a drop springs without shortening the life of the dampener so I went with those for that reason alone.
List of what was done and used:
List of what was done and used:
- 03-09 350Z Biltstein B8 Shocks
- 03-09 350Z LO Suspension 1" Drop Springs (Spring Rate Unknown) **Note: If I had to do again I would use 1.25" drop springs and Lincoln Mark VIII "adjustable coilover" tophats with custom aftermarket perch to drop the front end lower as the only con is the height of the 350Z shocks are taller than the MN12 ones (as documented in the Tien thread). I did not want to cut my $500+ Bilsteins.
- I did not use the factory cup washers as I noticed the stock tophats used cup washers to cup the bushings down where the aftermarket tophats were already cupped with the sleeve built in as one piece. **Note: If these shock mounts fail prematurely due to not using the cup washers from the original front shocks I am fine with that as that (this is my project car not a Daily) will be a reason to get the thinner Mark VIII coilover tophats and custom perches to drop the front end closer to where I would like. Right now I am not noticing/feeling anything sketchy with the cup washers being gone. I had to eliminate them to be able to get the shock nut on the shaft fully.
- Took both control arms to the machine shop to get the shock bushings trimmed down precisely so the 350Z shackles will fit the MN12 shock bushings properly
- Had machine shop also drill the shackles to ensure MN12 bolt properly fits through 350Z Biltstein shackle
- I am running Lincoln Mark VIII rear LCAs w/ SCP spring perches that fortunately raised the rear of the car to not have an awful "Carolina Squat" and sit closer to stock replacements albeit with much improved handling and bump absorption thanks to the better Bilstein dampers
- Unfortunately the 350Z shocks are taller and most of us do not want to cut them down so for those with significantly lowered cars (I am fine with stock-ish ride heights), the inserts are still a better option for you as the 350Z front shocks are taller.
- Besides 1.25" 350Z drop springs and Mark VIII air ride replacement "adjustable coilover" tophats, there is not much you can do outside of cutting (which I highly disagree with) the shock down to drop front ride height. The 350Z shocks are simply just taller than the MN12 ones.
- Slightly taller ride height is noticeable and might be aesthetically unpleasant to some though it is still fairly stock-ish **Note: Slightly taller ride height did not negatively affect handling in my experience (normal people will most likely not even visually notice)
- You cannot use the MN12 cup washers on the 350Z shocks due to a shorter shaft **Note: I will be monitoring this for premature wear, so far I feel nothing out of the ordinary nor do I visually see my shock mounts failing prematurely at the moment. The aftermarket shock mount/top hat I used does not use separate bushings that need to be cupped with a washer like the stock shock mounts and is already cupped/one-piece with the sleeve built-in. The nylock nuts that came with the Bilsteins appear very stout. Once the weight of the car is on them they look perfect.