Best TPI Bolt-Ons
Under $100
Adjustable Fuel Pressure Regulator
Crane's adjustable fuel pressure regulator provides rodders with the ability to tweak the fuel curve, which can not only help increase horsepower, but even improve fuel economy. It's not unusual for most DIY'ers to bump up their base fuel pressure 5 psi once they have added most of the bolt-ons mentioned in this article.
| Price: | $69 |
| Gain: | 15 rwhp |
| Performance: | .05 e.t. reduction and .05 mph gain |
| Install difficulty: | Medium |
March Underdrive Pulleys
March's underdrive balancer pulleys free up horsepower while still charging up the electronics. An easy install, save for the final torquing.
| Price: | $52 |
| Gain: | 5 rwhp |
| Performance: | .1 e.t. reduction and 1 mph gain |
| Install difficulty: | Medium |
Thunder Racing Air Foil
Aftermarket air foils smooth out the air path by eliminating the dead space between the throttle blades. While hard to measure, this is one of those supporting modifications that's hard to pass up and only helps as your car makes more power.
| Price: | $47 |
| Gain: | 5 rwhp |
| Performance: | .05 e.t. reduction and .05 mph gain |
| Install difficulty: | Easy |