Bolt-Ons

From 3.8Wiki

[edit] COMMON 3.8 MUSTANG BOLT-ONS

Cold Air Intake (CAI)

A basic cold air intake can be found on eBay or other online stores for under $50. While these kits won't add much power (the stock intake isn't much of a restriction on a stock car), adding other engine mods and free-flowing exhaust will magnify the CAI's worth.

Dual Exhaust

Many 3.8 owners opt for "GT Take-Off's". These are a great affordable option for adding dual exhaust on your 3.8 Mustang. The 2.25" tubing offers plenty of flow up to 300HP.

Under Drive Pulley (UDP)

Most people recommend the 25% vs. the 42% due to charging system limitations. These pulleys are dyno proven to free 7HP or so.

Intake Manifold Spacer

These spacers are commonly made from G10 Phenolic which is an excellent thermal insulator. By lengthing the intake runners and keeping the intake cool these spacers can add up to 5HP / 7ft lbs.

Tuner

Tuners can modify the stock ECU settings and provide better throttle response, advance engine timing, remove the speed governor, firm up shifts and more. SCT has been known as an excellent tuner for 3.8 Mustangs.