Audi S4 B8 / B8.5Stage 1 to Stage 4 tuning guide

What we'd do

On a B8 S4 the sweet spot is Stage 1 with gearbox software. A flash through the OBD port takes the supercharged V6 from 333 PS to 433 hp on 91 US octane, about our 95, and 444 hp on 93, our 98, on APR's dyno; 034 and IE claim similar gains. No hardware is needed. A single pulley at Stage 2 adds only 10–20 hp more on the same tuners' figures (034: 438 to 455 hp; IE: 416 to 435 hp), and it adds heat.

Our pick is APR, because it has a dealer in Israel and publishes a 95 figure: $649.95 for the engine file and $599.95 for its DL501 gearbox upgrade at NGP Racing, about $1,250 before shipping, tax and fitting. IE, whose Israeli dealer is Top RPM, is the alternative at $520 for its Core file. On a 2013-on car do the software first: owners say the factory rev limit costs power at the top end that the tune and gearbox file give back.

If you want Stage 2, fit a heat exchanger with the pulley, not after it. The engine computer cuts power when intake air passes 80°C, and 034's dyno shows the stock part getting there after a couple of pulls; its kit is $1,288. Skip dual pulleys: owners warn that the factory catalysts fail, and the extra power over a single pulley is small on 98. Stage 4's figures are on E40, which you can't buy here.

Fix the car before you tune it. Check the water pump and thermostat (2009–2010 cars were recalled), the crankcase (PCV) valve, and the factory crank pulley, whose rubber ring can separate and throw the belt. The S tronic's mechatronic unit is the costly failure, so service its fluid on time with Audi's fluid.

Tuning it in Israel

New price in Israel

No longer sold new; the importer's site (audi.co.il) lists no S4 today. Champion Motors launched the B8 S4 at ₪474,400 with the six-speed manual and ₪484,900 with the seven-speed S tronic (icar, 8 April 2009). We found no dated source for the facelift's price or for used prices, so we don't give one.

Parts from abroad

At the Bank of Israel representative rate of 26 October 2026 ($1 = ₪3.078), with 18% VAT and purchase tax, about 40.66% combined on car parts above $75 (our import guide):

• 034 heat exchanger $1,288 × 3.078 = ₪3,964, plus 40.66% (₪1,612) = about ₪5,576. At over $1,000 it is beyond the personal-parcel rules on our page.
• IE supercharger pulley $220.99 × 3.078 = ₪680, plus 40.66% (₪277) = about ₪957.

034's S34 intake ($455) is ₪1,400, about ₪1,970 landed. All before shipping, which is taxed too. APR's and IE's files are sold through their Israeli dealers, so ask them for a shekel price.

Fuel

Every tuner here publishes both pump fuels. On 91 US octane (about 95 RON) APR's Stage 1 claims 433 hp, 034's 430 hp and IE's 403 hp; on 93 (98 RON) 444, 438 and 416 hp. Unitronic's Stage 1 is a 91 file at 390 hp. So 98 is worth 10–13 hp here, and only if you fill with it every time. Stage 4's 534–548 hp figures are on E40, mixed from E85, which Israeli stations don't sell (95 vs 98 after a tune).

Regulation 380 and the test

The Road Safety Authority reads Regulation 380 as covering engine software, so record the tune like any other change (how approval works). Pulleys change the supercharger's speed and the engine's load, and the Ministry's list names a special exhaust outright: on this build the pulleys, the intake and any downpipe need approval, with a certified part, a licensed installer and the change recorded in the licence. AWE's downpipes keep the catalysts; a car with gutted catalysts or test pipes fails the annual test. Fixed noise fines are ₪250, or ₪350 for driving without an effective silencer.

Where to get it done

APR's dealer list names PIT-STOP in Holon, and Integrated Engineering's names Top RPM in Holon. Unitronic lists Max Tuning in Petah Tikva, Speed Doron Shimshi in Shoham and High Boost Performance in Nazareth. These are the brands' own lists, checked October 2026; we have no link with any of them. Contacts are in the box on the Hebrew version of this guide.

Prices and rules checked 2026-11-10.

Also useful: tuning shops in Israel, the import tax calculator and the annual test checklist.

What owners ask

Software and gearbox tune first, or the pulley?

Software first, say owners in a 2016 thread about a B8.5. One told the owner to buy Stage 1 and the gearbox tune while on sale, because he would want the gearbox file at Stage 2 anyway. A tuner's rep added that 2013-on cars should do both files before a pulley, to win back the power the factory takes away between 6,700 and 7,100 rpm; another owner liked being able to shift at 7,200 rpm instead of the stock 6,200 limit. Someone also noted that a bigger crank pulley replaces a part that is known to fail.

Sources: Audizine: TCU tune or pulley (2016)

How big a crank pulley can I run on the stock cooling?

A 2010 B8 S4 owner on 100-octane fuel asked this in 2019. Replies kept it around a 3.0 drive ratio on stock cooling, a crank pulley of about 179–187 mm with the stock supercharger pulley. A tuner's rep said APR's dyno 3.0T crossed its intake-air limit by the end of the first pull without a better heat exchanger, after which the engine bleeds off boost, and advised doing the heat exchanger with any pulley since the front comes apart anyway. On Israeli 95 or 98, in summer, we would stay at the small end.

Sources: Audizine: Pulley recommendation (2019)

What else breaks if I go dual pulley?

An owner of a 2013 S5 with 60,000 miles asked about a Stage 2+ budget in 2020. The detailed reply: the block is strong enough for the usual mods, the limits are fuel and intake temperature, full E85 is out and E30–E50 needs fuel pump upgrades. It suggested an overdrive crank pulley instead of the supercharger pulley, and warned that with dual pulleys the catalysts will fail, leaving you to gut them, fit test pipes or buy catted downpipes. In Israel both of the first two fail the test.

Sources: Audizine: Stage 2+ dual pulley upgrade (2020)

I'm buying a high-mileage S4 to tune. What will it need?

A B8/B8.5 owner listed his bills from about 74,000 to 184,000 km in 2024: a mechatronic repair kit, a fuel pump module, the supercharger belt, a full timing chain job with carbon cleaning, the PCV valve, water pump and thermostat, a gearbox clutch pack, and clogged catalysts replaced with test pipes. On IE's Stage 1 he logged 416 hp. Replies called carbon cleaning, the PCV valve and rear shocks expected by 100,000 miles, and stressed oil changes every 6,000–7,000 miles. Buy on history.

Sources: Audizine: Audi S4 B8/B8.5 life beyond 100K miles (2024)

Will a heat exchanger save my catalysts at Stage 2?

It helps the power, not the cats. A 2020 buyer found his 2016 S4 already on APR Stage 2 with dual pulleys and new catalysts. Owners told him to fit an upgraded heat exchanger, but explained that cooler intake air doesn't lower exhaust temperature: the cats sit close to the engine, and the more power you make, the harder life gets for them. In a 2022 thread an owner said the heat exchanger alone took his Stage 1 car from 11.8 to 11.69 seconds over a quarter mile, and another listed the PCV valve, thermostat and water pump as the usual jobs, a good time to clean the intake valves.

Sources: Audizine: Stage 2 and confused (2020), Audizine: What mods should I do next (2022)