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IRS Cobra Disc Conversion Installation Instructions
Disc to Disc/10.25 to 11.65 inch Rotor

Brackets and mounting hardware included in kit: 4-35mm bolts, 4-40 mm bolts, 2 thin nuts, 2 standard nuts,
4 spacers, 6 washers and 2 (two) conversion brackets.  Please read and follow all directions.

Additional parts list needed for installation: 

2 Rotors needed   # 81-125415 (2)
2 SN-95 COBRA Loaded Calipers (1) #16-4545-A and (1) #16-4544-A

[The calipers are the same whether it is a Cobra or any SN-95, but the intermediate brackets are different. The Cobra intermediate bracket MUST be used; so the calipers should be ordered ‘loaded’ in order to get the correct bracket.]

The bracket moves the caliper up and forward-it will be necessary to trim the dust shield to fit the new bracket and caliper.  Both sides are the same, the spacers go between the caliper and the new bracket.  Pictures of the install are on our website in the parts and accessories section.

Place vehicle securely on jack stands prior to starting disassembly.

  1. Do not paint any parts until all the parts have been test-fit.  Some fitting may be required and this will probably ruin any prep work.  All of the parts need to be test-fit first and then finished as desired.
  2. Take caliper apart from intermediate bracket. This will make the fitting of everything much easier.
  3. Mount IRS conversion bracket to the Cobra intermediate bracket using the two spacers provided and the 40-mm bolts provided (no washers).  Loc-tite™ should be used during final assembly, wait and check alignment first. 
  4. Mount Rotor to hub with a couple of extra lug nuts, tighten finger-tight. This is only to check alignment.
  5. Mount bracket to the inside of the spindle using two washers between the bracket and the spindle, one on each hole. Use the smaller 35mm bolts and nuts. The thin nut goes on the upper mount between the spindle and the intermediate bracket. Holding you tongue just right will help with this install. If the upper bolt comes too close to the caliper bracket, then use the extra washer provided under the bolt head to eliminate the interference.
  6. Check the fit of the conversion bracket to the spindle. It may be necessary to grind the casting flash off the spindle where the bracket meets the spindle at the top. Very little, if any, needs to be removed. Before grinding, install pads and check the alignment with the rotor to see if the bracket needs to be dropped down. The top of the pads should barely be below the top of the rotor. If they/it needs to drop down, remove the casting flash a little at a time. The aluminum of the spindle is very easy to work with, remove a small amount of material with a file or a small die grinder. Check the fit and remove more material if need. Use a piece of paper or plastic to find the interference and grind only where needed. As stated above, only a small amount of material needs to be removed.
  7. After all parts are finish fit, remove all nuts and bolts and reinstall with Loc-tite™ red thread compound. Paint parts as desired. If powdercoating, make sure all clearances are slightly larger as the powdercoating will cause interference.
  8. Install caliper.
  9. Install e-brake cables. 
  10. Install brake lines.  These can be either the stock super coupe (re-bent to fit) or braided lines.
  11. Bleed brakes, and test brakes in a SAFE area.


As with all parts installations, be careful while jacking, working on and lowering the car.