The Model 3 rear subframe, which all the suspension arms connect to, is mounted to the chassis with rubber bushings. These rubber bushings are quite firm, but they still allow some slight movement of the entire rear subframe under heavy loading. While this does not cause a shift in total toe, it can cause a change in thrust angle and allows for some lateral movement of the entire subframe during cornering. This causes a disconnection between the driver’s understanding of the rear tire grip. Is the tire sliding, or did the entire rear subframe just move under me a little bit? Our Model 3 subframe inserts help improve that connection your brain has to the tire.
We’ve been meaning to develop subframe inserts since 2018 when Tesla switched the very early production cars from solid subframe bushings to rubber. As you might imagine, Tesla did this to reduce noise in the car. So you should know that there is a slight increase in NVH with this part – mostly just some additional noise coming through from the rear of the car. It’s relatively minor, but it’s worth pointing out.
We’ve designed the kit to use an insert on both the top and bottom of the subframe, and we’ve fit the insert as tight as possible to the subframe. Because of this, there is effectively no opportunity for movement between the subframe and the chassis. After using these inserts at CSCS and beating a 991 Porsche Turbo, and recently setting an impossibly fast lap at Toronto Motorsports Park on 220 treadwear tires, the rear of the car felt more stable than it had previously, combined with a noticeable increase in rear grip and overall stability. With all of the arms changed there are very few points of compliance in the rear of the car remaining, so this makes solidifying the rear subframe more noticeable.
This is a cost-effective and easy-to-install modification that will be useful if you’re tracking your car. It’s totally bolt-on and reversible. As it adds a slight bit of NVH and the improvement is really only noticeable near or at the limit of adhesion, we’ve classified these as an MPP.R part – however, the increase in noise is very slight and you really have to be paying attention to notice it, so the part is also useful for those of you who are aggressive canyon carvers and already have the rest of the MPP arms on your car.
One huge bonus of this part is that it is extremely easy to install – simply remove one bolt at a time and let the subframe droop down, insert the top spacer which is laser marked, and then install the lower spacer. The entire job can be completed in around one hour by an experienced mechanic who is familiar with the platform.
NOTE: Fits Model 3’s Built BEFORE December 2020 ONLY.