A very popular modification for Subaru WRX and STI owners is improving the engine/transmission rigidity by changing motor mounts, transmission mount, and the engine pitch mount( also known as an engine pitch stop or dog bone).
One of the most readily available upgrades is the Subaru Group N pieces. A few Subaru dealerships even stock these pieces.
I’m trying one mod at a time, starting with the Group N motor mounts. These mounts definitely increase NVH( Noise, Vibration, and Harshness). That lumpy boxer idle is even more pronounced at idle. To me, it’s not a big deal- I kinda like it!
I then tried out the Group N pitch mount, and although the rubber bushings are harder in durometer over the OE piece, I wasn’t so thrilled about the OE-like plastic arm stamped STi- I always thought it was a reinforced(still plastic) piece. Oh well. I’m no engineer. So if it works, it works. Initial impressions- same amount of NVH, as far as I can tell. No real change in driving feel.
Anyways, in conjunction with some other mods I have on my car, especially that massive APS Top Mount Intercooler which makes underhood clearances as tight as it possibly can be, I noticed under hard acceleration that quick shifting causes the intercooler y-pipe to hit the firewall bracket supporting the pitch arm, slightly. Not a very comforting sound.
Removal of the Intercooler is necessary to access the Pitch Mount. 2 bolts and 3 hose clamps need to be removed, as well as a few hoses from the breather assembly.
Just recently, I got my hands on Super Pro’s Aluminum/Polyurethane engine pitch stop(p/n SPF3205). Nicely finished in a blue anodize(which will sadly go unnoticed thanks to my Intercooler), this piece looks more like a con-rod. The poly bushings are also a nice snug fit into the firewall bracket and motor bracket. Easy enough to install, save for the shoehorned intercooler as an obstruction, it’s just two bolts to loosen/tighten. Total time with a standard intercooler should be no more than 20 minutes. For you front-mount intercooler owners, even quicker.
With the intercooler removed, the pitch mount is clearly visible.
Initial impressions- not much NVH than the Group N pitch mount, and definitely no contact with the y-pipe and firewall bracket under quick shifts, as mentioned earlier. Great! Goes to show that some small changes can make a difference.
Comparison of the Super Pro and STi pitch arm
The Super Pro mount is a snug fit. A little grease helps fit it into its bracket.
Installed.
In retrospect, starting with this piece would’ve been a better start. I’m only guessing that this piece would’ve reduced the chances of the y-pipe interfering with the firewall bracket from the beginning. Next install is the Group N transmission mount. A bit more NVH to deal with…. yay.
Enjoy!