Everybody's first list of Audi S4 mods is the same: tune, intake, loud exhaust, done. Then the thermostat housing cracks at a stoplight and the car spends the summer on jack stands. The B8 and B8.5 S4's supercharged 3.0T responds to upgrades beautifully, but only when you do them in the right order. This roadmap walks you from reliability to bolt-ons, the TruDrive 3.0T crank pulley upgrade, cooling, brakes, and wheels, so every dollar builds on the last one.
Know Your S4 Before You Buy Audi S4 Mods
This roadmap is for the 2010-2016 B8 and B8.5 S4 (and most of it applies to the S5 3.0T and SQ5). All of these cars use the EA837 supercharged 3.0T, rated at 333 hp in US trim. Two details change your parts list:
- B8 (2010-2012) vs B8.5 (2013-2016): some valley parts, like the PCV valve and water pump part numbers, differ between early and later cars.
- 6-speed manual vs 7-speed S tronic (DL501): the dual-clutch needs matching TCU software and benefits from transmission cooling once power goes up.
Driving a 2018+ B9? That is a turbocharged EA839, a different animal. See our turbo Audi S4 guide instead.
Stage 0: Reliability First (Do Not Skip This)
Why start with parts that add zero horsepower? Because a pulley on an engine with a tired PCV valve and a cracking plastic thermostat is a very fast way to find out what the dealer charges for coolant-related tow-ins. On a car this age, Stage 0 is the foundation:
- ✅ Under supercharger refresh: thermostat, water pump, PCV valve, heater pipe, and gaskets in one job. B8 kit ($574.99) or B8.5 kit ($649.99).
- ✅ Ignition: fresh plugs and Zeus ignition coils for the EA837 ($129.99).
- ✅ Belt drive: the billet supercharger tensioner pulley ($64.99-$111.99) replaces the factory plastic piece.
- ✅ Mounts: the TruShift transmission mount ($19.99) and TruSport engine mounts ($299.99) cut the wheel hop and sloppy shifts that tired rubber causes.
For the full background on those failure points, read our Audi 3.0T supercharged engine guide.
Stage 1: Software and Breathing
With a healthy engine, Stage 1 software is the biggest bang for the buck on a stock S4. Pair it with parts that help the supercharger breathe and stay cool:
- ✅ Titanium Intake V2 for B8/B8.5 S4 ($359.99) for better flow and more induction sound.
- ✅ Luft-Strom 84mm throttle body upgrade kit ($219.99-$349.99) to open up the inlet to the blower.
- ✅ Sehr Gut intercooler port upgrade kit ($67.67) to improve coolant flow through the supercharger's intercoolers.
If you have an S tronic, add TCU software now. Faster shifts and higher clamping pressure make the whole car feel newer.
Stage 2: The Pulley Step
This is where the S4 wakes up. A bigger crank pulley spins the Eaton supercharger faster, so it moves more air and makes more boost everywhere in the rev range. It is the defining Stage 2 mod on the 3.0T, and it must be paired with software calibrated for that pulley size.
- ✅ Sizes offered: 179, 187, 193, and 207mm, so you can match the pulley to your tune and goals.
- ✅ Pair it with the Unzerstörbar high-strength crank pulley bolt kit ($64.99-$69.99) because you are disturbing a critical fastener.
- ✅ Budget for a fresh supercharger belt and check the tensioner at the same time.
Pulley vs dealer "performance" vs typical name-brand kits
The dealer has nothing for you here except a tune warning. Typical name-brand pulley kits work, but many are premium-priced alternatives for the same basic part. The TruDrive crank pulley for the Audi S4 costs $249.99-$329.99 depending on size.
| Vorsprung TruDrive | Typical name-brand pulley | Dealer / OEM | |
|---|---|---|---|
| What it does | Raises supercharger speed and boost | Same | Stock pulley only |
| Sizes | 179 / 187 / 193 / 207mm | Varies | One stock size |
| Needs matching software | Yes | Yes | N/A |
| Pairs with | Crank bolt kit, tensioner | Varies | N/A |
✅ Billet pulley hardware ✅ B8/B8.5 fitment help from real 3.0T owners ✅ Fast US shipping
Shop the TruDrive 3.0T Crank Pulley, $249.99-$329.99
Stage 3: Cooling and Exhaust
More boost means more heat, and the 3.0T's air-to-water intercoolers are only as good as the loop feeding them. If your car pulls hard once and then feels flat on the second run, heat soak is the reason.
- ✅ GP Ice heat exchanger v2 ($449.99) adds capacity to the intercooler loop.
- ✅ Pierburg coolant pump upgrade ($179.99-$289.99) moves more coolant through that loop.
- ✅ For S tronic cars, the DL501 DSG oil cooler adapter ($49.99) helps with transmission temps.
- ✅ Exhaust flow: high flow cats for the 3.0T ($1,049.99-$1,299.99) keep things street-friendly while freeing up the pulley's power.
Ready for more? A ported supercharger service ($749.99-$1,599.99) is the next big step. Our heat exchanger upgrade guide explains the cooling side in detail.
Stage 4: Brakes, Suspension, and Wheels
A faster S4 needs to stop, turn, and put power down. Do this before the track day, not after.
- ✅ Front brakes: Anker Street big brake kit ($1,849.99-$1,899.99) for B8/B8.5.
- ✅ Rear brakes: Haken Street rear big brake kit ($1,599.99-$1,649.99) keeps the electronic parking brake working.
- ✅ Suspension: Total Control RS TwinTrac coilovers ($1,399.99) and billet subframe inserts ($79.99).
- ✅ Wheels: forged sets like the VF-01 rotor style ($1,504.99-$2,794.99) from our forged wheels collection, plus a titanium lug kit. Plan wheel size around your brake choice.
Install Tips
- Stage 0 and the pulley are both supercharger-area jobs, so plan them together if you can and pay for labor once.
- Log intake air temperatures and fuel trims before and after each stage so you know what actually helped.
- Keep a spare supercharger belt in the garage once you run a pulley.
- Brakes and wheels need fitment checks: confirm caliper clearance before ordering forged wheels.
Want the parts list organized by category and budget instead of by stage? See performance parts for the Audi S4.
Audi S4 Mods FAQ
What are the best first Audi S4 mods?
On a B8 or B8.5, start with reliability: the under supercharger refresh, coils and plugs, and mounts. Then add Stage 1 software, an intake, and a throttle body upgrade. Those are the best first Audi S4 mods because everything after builds on them.
What order should I do Audi S4 mods in?
Reliability first, then software and breathing, then a crank pulley with matching software, then cooling and exhaust, and finally brakes, suspension, and wheels.
Does a crank pulley need a tune on the B8 S4?
Yes. A larger crank pulley raises boost, so the calibration must be written for that pulley size. Running a pulley on the wrong software is asking for knock and poor drivability.
Is the B8 S4 good for modding?
Yes. The supercharged 3.0T responds strongly to software and pulley upgrades and has a large aftermarket, as long as the known cooling and PCV issues are handled first.
Do I need a heat exchanger upgrade on a modified S4?
If you run a pulley or drive hard in hot weather, a larger heat exchanger and better coolant pump help keep intake temperatures and power consistent over repeated pulls.
Are B8 and B8.5 S4 parts the same?
Many are shared, including the intake, pulley, and brakes, but some valley parts like the water pump and PCV valve use different part numbers. Confirm your model year before ordering service kits.
Do these Audi S4 mods apply to the B9?
No. The 2018+ B9 S4 uses the turbocharged EA839 engine, so its upgrade path is different. This roadmap is for the supercharged B8 and B8.5.
Bottom Line on Audi S4 Mods
The best Audi S4 mods follow an order: fix the valley and ignition, add breathing, then the TruDrive crank pulley for the Audi S4 3.0T with matching software, then cooling, brakes, and wheels to use it all. Do it in that order and your B8 or B8.5 makes repeatable power instead of repeat visits to the dealer.
Shop the TruDrive Crank Pulley, $249.99-$329.99
Drive the difference. Drive Vorsprung.
Prices checked September 25, 2026 and subject to change.
