do i need STI tranny mount?
 

I'm trying to decide if i should get a STI tranny mount or use my 98 Forester tranny mount for my upcoming 5-speed tranny conversion in April. I was getting ready to order one and was searching the net for the cheapest STI tranny mounts. Came across a couple Impreza forums talking about STI Tranny mounts. Some Impreza owners have put them in. There has been concern about STI mounts causing extra strain on the 5-speed transmission. There has been suggestions as to use stock mounts and the transimission will last longer under hard use. I would like to hear thoughts from 5mt SVX owners with STI Tranny mounts and also from those useing Stock 5mt Donor Mounts

I'm still using the stock WRX mount but I am considering getting the STi mount from 1stsubaruparts.com

I plan on upgrading all the mounts (engine, tranny, rear diff mount) as well as bushings as soon as I can get enough interest in a group buy.

There was a thread on NASIOC where some people were speculating that installing only an STi (Grp N) tranny mount and not Grp N motor mounts would put extra stresses on the tranny mount. Might be true, but hard so say how much extra stress.

I guess you could also speculate that having stiffer tranny (and motor) mounts could remove some cushioning in the driveline take-up and thus put more stress on the gears. Hard to say about that too because the driveline itself is very springy.

The one thing that seems to be a certainty (at least in reading threads on NASIOC) is that adding Grp N motor and tranny mounts makes the car easier to drive because it removes some bounciness from the driveline.

It's funny but cars with solid mounts tend to break their mounts more easily than rubber ones (yup, I've got a few years of racing experince to back that up.) Firm rubber is good, shouldn't cause any problems at all. Soft mounts are only for cushiness and can actually lead to linkage, exhaust breakage and premature u-joint wear/vibration.