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Bolt-on upgrades 4.2L (N/A)

Unlike the (b8.5) with turbos, the B8’s have a Naturally Aspirated V8 that leave you with little room for major power upgrades. Dyno jet numbers on stock B8 S5s have put down around 297 whp / 296 wtq.

For bolt-on upgrades, you’re limited to Air Intake, Exhaust/dp, and an ECU upgrade. A few performance shops out there, but APR stands out the most with performance parts & quality.

The APR – Stage I upgrade parts (which I have installed as well):
– ECU upgrade adding +15 BHP / +14 Ft-lbs torque. (at crank)
– Carbon Fiber Intake System with a claimed +10 HP (at crank)
– RSC Exhaust System (IMHO, the best sounding exhaust on a B8 S5)

I honestly did not feel any power gains over stock. I was easily smoked by an S4 (b8) V6 with Stage II upgrades, at which that point I researched for the next best option for more power…a supercharged option was the only way to go from there.

Supercharger Upgrade (Stage II)

No stage II options on the (b8) V8s, only III, which is with a Supercharger System upgrade. This upgrade will definitely be noticeable, as it increases crank hp around 350-360 to 590 hp (on pump 93) and 640 on e85/race fuel.

APRs Supercharger uses a TVS1740. A direct easy install with a $13,000 price tag.