# Akrapovic 991 GT3 Exhaust Install Guide Fit the Akrapovič Slip\-On Race Line to a Porsche 911 GT3 \(991\.2\), following the maker's manual step by step By Carbonwurks Topic: Home & DIY [Open the interactive Jig](https://ask.jig.com/j/7kFbXlI9MkNV) ## Transcript ### 1. Akrapovič Slip\-On for the 911 GT3 This titanium Slip\-On replaces the GT3's stock centre muffler, the box that quiets the exhaust at the very back of the car\. The car stands on a two\-post lift with its engine off and cold\. On the floor: the Slip\-On, its tailpipes, four reduction bushes, four band clamps and the fitting bolts\. Tap any part to see its name\. For skilled technicians\. Let the exhaust cool completely first: it gets extremely hot\. ### 2. R1 · Unscrew the Panel Bolts Under the engine, unscrew the twelve marked bolts that hold the under\-engine panel, a flat cover that protects the engine from below\. A lift lets you stand comfortably underneath\. ### 3. R1 · Lower the Under\-Engine Panel Carefully lower the panel away from the car and set it down\. Keep its bolts together so they all go back later\. ### 4. R2 · Bumper Bolts Underneath Unscrew the six marked bolts on the underside of the rear bumper: two beside the tailpipes and two at each wheel\-arch edge\. The bumper stays in place for now\. ### 5. R3 · Bumper Screws on Top From the engine bay, unscrew the six marked screws along the bumper's top edge\. Two sit in each outer corner, the rest along the middle\. ### 6. R4 · Remove the Tail Lights Pull both tail lights gently out of the body, unplug their electrical connectors and lift them away\. Take care not to damage the connectors\. ### 7. R5 · One Side Bolt Each Side Unscrew the marked bolt low on the side of the body, on both sides of the car\. It holds the edge of the bumper where it wraps round the corner\. ### 8. R6 · Wheel\-Arch Bolts Unscrew the two marked bolts at the rear of each wheel arch, where the bumper meets the arch liner\. The liner is the plastic shell inside the arch around the tyre\. ### 9. R7 · Take the Bumper Off Unplug the bumper's electrical connectors, then ease the whole bumper straight back off the car\. ### 10. R8 · Heat\-Shield Bolts Unscrew the four marked bolts of the central heat shield\. A heat shield is a shiny metal plate that keeps exhaust heat away from the body\. ### 11. R8 · Remove the Central Heat Shield Lift the central heat shield away and set it down\. It goes back on once the new system is fitted\. ### 12. R9 · Side Heat\-Shield Fasteners Unscrew the marked bolts and nuts holding the side mufflers' heat shields, on both sides of the car\. ### 13. R9 · Remove the Side Heat Shields Take both side heat shields off the car\. Now the stock centre muffler and its joints are in clear view\. ### 14. R10 · Loosen the Side Brackets Loosen the side mufflers' bracket and the marked clamps on both sides\. Back the nuts and bolts off until only a few threads still hold, so the pipes can move a little\. ### 15. R11 · Unscrew the Flange Nuts Unscrew the marked flange nuts where the pipes join, on both sides of the muffler\. A flange is a flat collar that bolts two pipe ends together\. ### 16. R12 · Unscrew the Muffler Clamps Unscrew the two marked clamp bolts that hold the stock centre muffler\. ### 17. R12 · Lower the Stock Muffler Lower the stock centre muffler, with its clamps, away from the car\. Keep it: you may need it where the new system is not road legal\. ### 18. I1 · Bushes and Clamps onto the Slip\-On Slide a reduction bush and a band clamp onto each of the Slip\-On's four inlet pipes\. A reduction bush is a slit metal sleeve that makes the joint fit snugly\. Tip: first coat the outside of each bush with Akrapovič ceramic anti\-seize grease \(white tube\)\. ### 19. I2 · Fit the Slip\-On Lift the Slip\-On up into place so its inlets slide into the stock pipes, and hand\-tighten the clamps\. Tip: if the pipes are hard to insert, remove one side muffler, fit the Slip\-On, then refit the side muffler\. ### 20. I3 · Bolt the Brackets Line the Slip\-On up with the body, then bolt its two brackets to the muffler bracket with the M8 × 16 bolts from the Akrapovič kit\. Tighten them to 22 newton\-metres, a measure of twisting force\. ### 21. I4 · Retighten the Side Brackets Tighten the side mufflers' bracket bolts and clamps that you loosened earlier to 22 Nm \(16 ft·lb\)\. This locks the side sections firmly to the new Slip\-On\. ### 22. I5 · Align and Torque the Clamps Turn all four band clamps so they line up neatly, then tighten each to 34 Nm \(25 ft·lb\) with a torque wrench\. ### 23. I6 · Offer Up the Tailpipes Slide the two titanium tailpipes onto the Slip\-On's outlets, against its tail plate\. Their insides show a blue heat tint\. ### 24. I6 · Bolt and Nuts, Hand\-Tight Fit the M8 × 17 bolt with its washer in the centre, and an M8 nut on an eccentric washer at each side\. An eccentric washer has an off\-centre hole, so turning it nudges the tailpipes sideways\. Hand\-tighten only for now\. ### 25. I7 · Refit the Stock Parts Refit every part you removed: heat shields, under\-engine panel, tail lights and bumper\. Use the car maker's manual for their procedures and tightening torques\. ### 26. I8 · Centre and Torque the Tailpipes Turn the eccentric washers until the tailpipes sit centred in the bumper cut\-out, then tighten the bolt and both nuts to 22 Nm \(16 ft·lb\)\. ### 27. Ready for the First Start Check that every nut and bolt is tight and nothing touches the body\. Clean the titanium with a multi\-purpose spray lubricant before starting, or stains will burn on\. A little white smoke at first is normal, and the titanium slowly colours with heat\. Never stand behind the exhaust\. Check local noise and emissions rules\.