DIY Ohlin R&T coilovers and Tarett suspension install

This setup is typical for 981 owners who track their car and still drive on the street at least part time. You can choose different coilovers or suspension parts, but the installation is the about the same.

Credit goes to txbdan on Rennlist for his X73 Suspension Install Notes. A few additional steps are needed for the Lower Control Arms and tie rods. I'll share more details below.

Torque Values

  • Front

    • LCA to cross member: 89 ft-lb

    • LCA balljoint to wheel carrier: Tarret LCA 120 ft-lb (retorque after first hour), Stock 63 ft-lb

    • LCA to diagonal arm (nut and bolt): 118 ft-lb

    • Tie rod to wheel carrier: 63 ft-lb

    • Sway bar drop link to wheel carrier (strut pinch bolt): 63 ft-lb

    • Strut to strut tower, three M8 hex: 24 f-lb

    • Sway bar bracket to subframe: 48 ft-lb

    • Sway bar drop link to Sway bar: 30 ft-lb + 30deg

    • Subframe front, outer two bolts (through diagonal arm): 67 ft-lb + 180deg - Always use new bolts

    • Subframe front, inner two bolts: 67 ft-lb + 90deg - Always use new bolts

    • Subframe front, two nuts: 67 ft-lb + 90deg - Always use new nuts

    • Subframe rear, two bolts on each side: 67 ft-lb + 90deg - Always use new bolts

    • Support frame (black steel): 48 ft-lb

    • Stud to front body for lock nut: 22 ft-lb

    • Steering rack to subframe, two bolts: 52 ft-lb - Always use new bolts

    • Coolant pipes: 7.5 ft-lb

    • Brake disk to wheel hub: 7.5 ft-lb

    • Brake caliper to wheel carrier: 63 ft-lb


    Rear

    • Toe control arm ball joint to wheel carrier - Tarett: 56 ft-lb (stock 63 ft-lb)

    • Toe control arm to rear subframe - Tarett locking plate: 74 ft-lb (stock eccentric bolt): 81 ft-lb

    • LCA to rear subframe (eccentric bolt): 81 ft-lb

    • LCA ball joint to wheel carrier: 63 ft-lb (stock)

    • Diagonal arm to LCA (nut and bolt): 118 ft-lb

    • Strut to strut tower, three M8 hex: 24 ft-lb

    • Drop link strut pinch bolt to wheel carrier: 37 ft-lb + 180deg

    • Rear sway bar bracket to rear sub frame: 24 ft-lb

    • Sway bar drop link to Sway bar: 30 ft-lb + 30deg

    • Drive shaft to transmission flange: 59 ft-lb

Installation

I followed the X73 Suspension Install Notes guide for most of the build. Tarett's website is also a good resource for installing thier components especially when a different torque is needed. I also used manual supplied with the Ohlins coilovers.

I replaced almost every nut and bolt. You have to replace some but not all. I tend to err on the side of caution. I also torque everything and mark with a paint pen as I go.

The Tarett Lower Control Arms need spacers between the stock thrust arm and center puck. They are not needed if used in the rear. I did have to open up the hole in the wheel carrier to accept the 14mm ball joint bolt. A 9/16" drill worked fine.

Once everything is together try and adjust your front and rear toe. It doesn't have to be perfect, just good enough that your car tracks straight and you can drive it to get an alignment.

I later upgraded the rubber spec LCRs with the race spec versions. They have solid pucks and sealed monoball inner ends. In the rear I upgraded the stock LCRs with solid pucks and monoballs. This made a big difference on the track but further reduced ride quality on the road. I would only recommend going with the solid bushings if you primary use your car for track days.

Tools

  • Variety of wrenches and sockets including 10, 13, 15, 16, 17, 19, and 21mm

  • 21mm strut nut socket (stock is smaller)

  • 14mm or 9/16 drill - Tarett LCR ball joints are bigger, and you may need to open up the hole in the wheel carrier (installation instructions)

  • Ball joint separator

  • M10 allen socket for axle flange bolts (I read newer cars are triple square)

  • Several different torque wrench sizes. I like DeWalt torque wrenches and own this 3/8" drive model.

New Nuts and Bolts

  • Nuts

    • 90038001201 (PAF103353)

    • 90038000801 - sway bar X4

    • 99908444909

    • 99908444501

    • PAF008756 - Cross-Member Mount Bolt X2

    • N90916701 - Cross-Member Reinforcement Nut X2

  • Bolts

    • 105mm 99907286401 (PAF008757)

    • 60mm N91148901

    • 50mm 99907286301 (PAF008756)

Suspension Components

  • Ohlins Road and Track Coil Over Kit

  • Tarett GT3 front sway bar with bushings

  • Tarett GTS rear sway bar with bushings

  • Tarett front and rear drop links

  • Tarett rear toe links

  • Tarett rear locking plate

  • Tarett Cup-Series lower control arms (rubber spec later replaced with race spec), spacers, and shims (front only)

  • Tarett front tie rods with bump steer

Nuts and bolts purchased at FCP Euro