The aFe Silver Bullet Throttle Body Spacer (46-31001) is a spacer machined from 6061-T6 billet aluminum that sits between the throttle body and the intake manifold on the N62 V8. Its serrated/helix entry creates turbulence at the manifold while eliminating the whistle found in helix-only throttle spacers. The spacer also lengthens the intake track, which helps increase intake air speed and improve throttle response.
The reason to pick this over a plain or helix-only spacer is the serrated/helix combination, which the manufacturer says also reduces intake whistle that occurs with helix-only designs. Set expectations carefully. I could not find a published dyno figure for this part, and owners on user forums describe mixed views on the tb spacer, with one calling for a dyno result. The value here is a machined, bolt-in intake change with a quieter entry, not a guaranteed horsepower number.
The manufacturer lists this part for the BMW X5 (E53) 04-06 with the V8-4.4/4.8L N62. Search results also showed 5 Series and 6 Series applications in the product name, which I could not confirm on the manufacturer's page, so verify fitment before ordering. Searchers looking for an N62 V8 throttle body spacer, E53 X5 4.8is intake spacer, or serrated helix spacer with no whistle will find this part's application details below.
The manufacturer lists the BMW X5 (E53) 04-06 with the V8-4.4/4.8L N62. The 5 Series and 6 Series applications that appear in some listing titles were not confirmed on the manufacturer's page, so check with the manufacturer before ordering for those vehicles.
aFe's install sheet for a related Silver Bullet spacer states the design is intended for the stock intake system, and that aftermarket intake systems may need modifications. Confirm compatibility with the manufacturer for this specific part number.
Owners on user forums report mixed results, and some have asked for dyno comparisons. The manufacturer's information for this part does not include a dyno-verified horsepower or torque figure.
This is a moderate DIY job. Aside from removing the engine cover, you need to pull the air inlet tube, air filter, and air cleaner assembly, then disconnect the throttle body harness before removing the throttle body. Basic metric sockets, a 10 mm and 14 mm socket and wrench, a 5 mm hex key, and a flat-head screwdriver cover most of the work, based on aFe's sheet for a related Silver Bullet spacer. Set the spacer with its engraved side facing the throttle body and place the supplied gasket between the spacer and throttle body. Use the longer bolts with washers, then torque them to 10 Nm, as the manufacturer specifies for the related spacer. Keep the intake manifold O-ring in place when you remove the old gasket, and on vehicles with a strut tower brace, mark the adjuster nut positions before loosening it. Confirm the torque and kit contents against the install sheet for 46-31001 before you start.
