I got rid of the squishies!
Some of us who drive the early-VIN performance cars know of that "squishy" feeling when you accelerate aggressively through turns. The car feels like it rolls, and is missing a "firmness" in the turn that allows for more positive control in acceleration. Note that I'm not an expert in suspensions by any means, so I'm using the "technical terms".
I decided I wanted to find something that would get rid of them.
I attempted to do what Laurent did
in this post, because it sounded like what I wanted as well. Like Laurent, I wasn't interested in the stiffer ride so I didn't feel the need to replace the air shocks. I worked with the service advisor, who placed the order for the parts for me. Apparently, it sent up a few red flags and a few folks at corporate reached out to the service advisor asking what we were trying to accomplish. Unfortunately, in the end Tesla declined to do a partial upgrade and stated rather decisively that partial upgrades using P+ components on an originally-delivered P car is not supported, and service centers will not (or no longer) do them. EDIT: they will do a FULL P+ retrofit at a cost of ~$20k (added for clarity).
However, after consulting with lolachampcar, I took a slightly different approach. He suggested I just ask them to upgrade the car to the current production specs for P85 cars, with current-rev lower control arms and rear subframe -- that the replacement of just those parts would make the biggest difference in removing the squishies. The service center exchanged a few messages with chassis engineering on my requests, and they concurred that the idea would best accomplish what I want, with one other recommendation - a replacement of the upper links as well, which have been revised since the Sig cars. Chassis engineering signed off on the changes and the parts were installed while I was out of town this week.
EDIT: I should also note that the parts that were installed - sub-frame, LCA, and upper links - are all common between P and P+ models as well.
The car was returned to me today and tonight I took it out for a test. I have to say that I am very, very pleased with the results; the car's ride remains as a sedan should be (so it's not a rock-hard race car) but the squishies are gone under hard acceleration in turns. While turning, the car hangs onto its rear end now.
The price of the change was ~$5k including parts/labor.
A big thanks to both Laurent and lolachampcar for their help during the process.
