Ford Mustang GT S550Stage 1 to Stage 4 tuning guide

What we'd do

The Mustang GT is the odd one out on this site: a naturally aspirated V8 with no turbo to turn up. Stage 1 adds little, about +19 hp at 6,500 rpm with Ford Performance's calibration kit, and most of what tuners get from the Gen 3 Coyote comes on E85, which Israeli pumps don't sell. So we see two sensible choices: a mild Stage 1 for the way the car drives, or a supercharger at Stage 3. The steps in between cost more than they give.

For Stage 1 on a 2018–2021 car we would take Ford Performance's kit ($1,535): the calibration, a cold air intake and an 87 mm throttle body. The gain we would notice is not the peak figure but +42 lb-ft at 2,000 rpm. It is VIN-locked, keeps a Ford Performance parts warranty when a Ford dealer or ASE-certified technician fits it, and doesn't fit the Bullitt or Mach 1. If the car already has other parts, a Lund custom tune from $325 (tuner device extra) is the cheaper route.

If you want real power, go straight to a supercharger. Ford Performance's kit, built by Roush, claims 750 hp on 91 US octane (about 95 RON) at about 12 psi for $6,950; Roush's own Phase 2 claims the same 750 hp on 93 for $8,799.99. Check your car first: Roush says its kit doesn't fit Euro 6.2-spec cars, and Ford Performance develops its calibrations for US and Canadian cars only. Budget for the driveline from day one. On a manual, the Tremec Magnum XL swap is $6,200 and rated for 700 lb-ft; the 10-speed automatic holds about 700 hp on stock clutches, according to Brady Performance.

What we would skip: long-tube headers at Stage 2. BBK says 30+ hp is typical, but they need new mid-pipes, a tune, and they carry no emissions approval, which makes them the hardest part on this car to get through the test here. Skip Stage 4 too: forged short blocks and E85 fuel systems are built for a fuel Israel doesn't sell. Our budget: $1,535 for Stage 1, or $6,950 for the supercharger kit plus $6,200 for the gearbox on a manual car, before shipping, tax and fitting.

Tuning it in Israel

New price in Israel

The S550 was never sold new by an official importer here. Official sales began in April 2024 with the next generation, imported by Delek Motors (auto.co.il). In May 2026 the 5.0 V8 GT with 480 hp was listed at ₪445,000 (auto.co.il, 26 May 2026), and auto.co.il's model page lists versions up to ₪505,000. An S550 on Israeli plates came in through personal import, so check whether it is a US or a European car before you order parts.

Parts from abroad

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

• BBK long-tube headers $849.99 × 3.078 = ₪2,616, plus 40.66% (₪1,064) = about ₪3,680. They are an exhaust part, so they need an approval at import, and they need mid-pipes too.
• Ford Performance calibration kit $1,535 × 3.078 = ₪4,725 before tax; at 40.66% that is about ₪6,646. It is over $1,000, beyond the personal-parcel rules on our page, so ask customs first.

A supercharger kit ($6,950 × 3.078 = ₪21,392 before tax and shipping) is a freight import, not a parcel.

Fuel

Israel sells 95 and 98, roughly US 91 and 93. Ford Performance's supercharger kit claims its 750 hp on 91, so 95 is enough. Roush calibrates its Phase 2 for 93 and Whipple quotes its figures on 93, so run 98. Ford Performance says its calibration kit needs premium fuel for full performance. Ignore the E85 and flex-fuel tunes: E85 isn't sold at Israeli filling stations. See 95 vs 98.

Regulation 380 and the test

Under Regulation 380 a special exhaust and any mechanism the maker didn't design are a change of structure, so a supercharger kit and long-tube headers both need a permit and a licensed installer. BBK lists its headers as not CARB-approved, and most long tubes are sold for off-road use only. Keep the original exhaust manifolds and catalysts so the car can go back for the annual test. A loud exhaust also risks a ₪250 noise fine. Tell your insurer in writing.

Where to get it done

None of the brands in this guide (Ford Performance, Roush, Whipple, Lund, BBK and the rest) appears on the Israeli dealer lists we track, which come from the brands' own dealer pages, checked October 2026. Ford's importer, Delek Motors, sells the current Mustang; ask its service network before you assume it will work on a personal-import S550 with aftermarket parts. See also tuning in Israel.

Prices and rules checked 2026-11-02.

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

What owners ask

Is a tune worth it on a stock 2018+ Mustang GT?

For peak power, not much. Ford Performance claims +19 hp at 6,500 rpm for its 2018–2023 kit, and that already includes an intake and a bigger throttle body. The bigger change is low down: +42 lb-ft at 2,000 rpm. Lund's custom tune starts at $325 but doesn't include the flash device, and its E85 option, where the Coyote gains most, is no use in Israel. A tune makes more sense once the car has headers or a power adder that need one.

Sources: Ford Performance: 2018–2023 GT calibration kit, Lund Racing: 2018–2023 GT custom tune

Will a tune or supercharger void my Ford warranty?

Ford's own parts are the safe route. Ford Performance's calibration kit and its 750 hp supercharger both carry a 3-year/36,000-mile limited warranty, counted from the car's in-service date, but only when a Ford dealer or an ASE-certified technician installs them. Roush's Phase 2 warranty covers Roush parts only. A third-party tune has no such cover. On a personal-import S550 in Israel, check in writing what, if anything, the importer will cover.

Sources: Ford Performance: 2018–2023 GT calibration kit, Ford Performance 750 hp supercharger (Speedshop Direct)

What else do long-tube headers need?

More than the box suggests. BBK says its long tubes must be used with its own short mid-pipes, and that the front oxygen sensors need wiring extensions, which aren't included; 2015+ cars also need a hardware kit. The headers change the exhaust layout, so the engine needs a tune written for them. BBK lists them as not CARB-approved. Choose catalysed mid-pipes and keep the stock manifolds for the test.

Sources: BBK: 1-7/8" long-tube headers

Will my gearbox take a supercharger?

The automatic, mostly yes. Brady Performance says the 10R80's stock clutches hold about 700 hp, that it would add clutches and rebuild the gearbox from about 750 hp, and that the E and F clutches fail first. It fits an extra cooler above 700 hp. The kits here claim 610–670 lb-ft. For the manual, the usual fix is JPC's Tremec Magnum XL swap: $6,200, rated for 700 lb-ft, plus $425 shipping.

Sources: FordMuscle: 10R80 Q&A with Brady Performance (2022), JPC Racing: Tremec Magnum XL conversion

Do the supercharger kits fit a car that isn't US-spec?

Not always, and in Israel this matters. Roush says its 2018–2021 Phase 2 kit fits the 5.0 GT but not the Mach 1, Bullitt, GT350 or Euro 6.2-spec cars. Ford Performance says its supercharger calibrations are developed and supported for US and Canadian cars only, and the kit doesn't fit the Bullitt. Before you order, give the seller your VIN and ask whether the kit and its tune support your exact car.

Sources: Roush: 2018–2021 Phase 2 supercharger, Ford Performance 750 hp supercharger (Speedshop Direct)