Simply replacing the torque mount with one of the firmer options will completely transform the driving characteristics of the car. Shifts will feel smoother both in manual and automatic cars and there will be less wheel hop off the line resulting in slightly quicker acceleration. The only draw back is that a firmer mount will transfer more vibrations into the frame of the car. This can make the car feel rougher at idle and will also accentuate the amount of noise in the cabin. However, if your intentions are to transform your P1 Volvo into a sporty driving machine, upgrading the torque mount should be one of the first modifications.
Please visit FCP Euro to read my recent article: How to Remove & Replace Transmission Torque Mount on a P1 Volvo (C30, S40, V50, C70)
You can also watch my video on torque mount removal:
I have personally tried five different torque mount options for the universal C1 platform cars. Below are quick summaries of each mount.
Volvo OEM (part # 31277241): It's a sloppy stock mount, but cabin noise and vibration are virtually nonexistent.
Elevate Performance Engine Mount: Initially, the mount was very firm and transferred a noticeable amount of noise into the cabin. It smoothed out after about one month of use, but the bushing itself only lasted me 40k miles before it needed to be replaced.
Ford eFocus (part# CM5Z-6068A): Probably the best bang for your buck. This mount can be purchased for less than $50. It provides all the improvements of an upgraded torque mount, but with minimal noise or vibration.
Chinese CM5Z 6068A: Be extra careful when shopping for the eFocus mount, because a Chinese company has made an knock off and named it after Ford's part number. It is a little bit cheaper in price, so I thought I would give it a try. While it provides all the same driving benefits at the eFocus mount, this bushing failed after only 30 days of use!
WhiteLine Bushing Insert: The WhiteLine bushing insert is only compatible with the Mazda 3 factory mount, contrary to what is listed on their website. Having installed a Mazda 3 mount with the WhiteLine kit, I would rank this equally as good as the eFocus mount. However, it did require some modification to make it fit right, so I would still suggest the genuine Ford part over this.