- 1¾″→1⅞″Double-stepped, equal-length primaries
- 304 SSHeaders, cats and connectors
- ×2Race-merge collectors, one per bank
- Bolt-onConnector pipes included
Ramjet Performance Parts // Mustang GT 5.0L Coyote 2015-2023
Ramjet Mustang GT Double-Step Headers & Cats
★★★★★Double-stepped equal-length headers, flanged high-flow cats, and the connector pipes that bolt it all to your standard cat-back.
Happy Ramjet owners
- ★★★★★
“Gave me 35kw at rear wheels with standard cat back and KandN cold air.319kw”
Graham M. - ★★★★★
“Great Product”
Rob
- ☎Talk to the team03 9746 6656
What's in the box +
2× double-step headers (equal-length, 1¾″→1⅞″, 304 stainless) · 2× high-flow cats (100-cell metal or 200-cell ceramic) · connector pipes to join the cats to your standard cat-back · cat gaskets & bolts.
Shipping & returns +
$99 flat-rate delivery Australia-wide on exhaust orders, insured and tracked. Ships worldwide. Unopened items can be returned within 7 days. Not sure it fits? Call 03 9746 6656.
Equal-length. Double-stepped.Built for the Coyote.
Our flagship Mustang header: the proven equal-length, long-tube design, pushed further with stepped primaries that hold exhaust velocity down low and open up flow up top.
Why Ramjet
Factory vs Ramjet
 |
OEM
Factory manifolds | |
|---|---|---|
| Long-tube primaries | ||
| Equal-length runners | ||
| Stepped 1¾″ → 1⅞″ primaries | ||
| Race-merge collectors | ||
| High-flow catalytic converters | ||
| 304 stainless steel | ||
| Bolts to the standard cat-back | ||
| Add to cart |
Power gains depend on your engine, supporting modifications and tune.
Why it works
Double-stepped primaries
Each primary steps from 1¾″ to 1⅞″ part-way down its run. The smaller first section keeps gas speed high for torque and response; the larger second section lets a high-horsepower Coyote breathe up top.
Race-merge collectors
The four primaries on each bank merge through a race-style collector rather than a blunt plate. The gas stream stays attached, back-pressure stays low, and the mid-range comes in harder.
Metal for NA. Ceramic for boost.
The 100-cell metal core is the pick for a naturally aspirated Coyote; the 200-cell ceramic is built for supercharged and turbo engines.
Bolts to your standard cat-back
The connector pipes that join the cats to the factory cat-back come in the box. No fabrication, no separate parts to order.
The details
Specifications
- Fitment
- Ford Mustang GT 5.0L Coyote V8 · 2015–2017 & 2018–2023 (S550)
- System
- Long-tube headers + high-flow catalytic converters + connector pipes
- Primary design
- Equal-length, double-stepped 1¾″ → 1⅞″
- Collectors
- Race-merge collectors
- Cat options
- 100-cell metal core (naturally aspirated) or 200-cell ceramic core (forced induction only)
- Material
- 304 stainless steel throughout
- O2 sensors
- Extension harness available for 2015–2017 and 2018–2023 — select above if you don’t already have one
- Fitment type
- Direct bolt-on · works with the standard OEM cat-back · tune recommended for full gains
Frequently asked questions
Will these fit my Mustang GT? +
Yes — they fit the S550 Ford Mustang GT with the 5.0L Coyote V8, both 2015–2017 and 2018–2023. They are for the GT only; they do not fit the EcoBoost or the V6.
Do I need to change my cat-back? +
No. The connector pipes are included, and the kit bolts straight up to the standard OEM cat-back. It will also join to most aftermarket cat-backs that start from the factory location — call us if you are running something unusual.
Metal or ceramic cats? +
100-cell metal is the pick for a naturally aspirated Coyote. 200-cell ceramic is for forced-induction engines only (supercharged or turbocharged).
Do I need the O2 sensor extension? +
Long-tube headers move the sensor positions, so most cars need an extension harness. Pick the one for your year above. If you already have a set from a previous install, choose “No”.
Do I need a tune? What gains should I expect? +
The headers and cats bolt on as supplied, but a tune is strongly recommended. Owners typically see in the region of 70 hp with a tune, depending on the year, supporting modifications and the rest of the exhaust. We can tune it in the workshop at Melton.
Are they road legal? +
The high-flow catalytic converters are retained, so the car keeps its cats and street usability. Emissions and noise rules vary by state, so check your local regulations before fitting.
Who should install them? +
A competent home mechanic can fit them, but we recommend a professional exhaust or performance workshop. We fit and tune these ourselves at 23 Reserve Road, Melton VIC — call 03 9746 6656 to book.
Fitted. Driven. Reviewed.
Verified feedback from Mustang GT owners running the Ramjet double-step headers.