The stainless steel exhaust range for the MGB is manufactured by Double S Exhausts in 309 and 401 grade stainless steel with mirror finish silencers, produced to accurate tolerances for straightforward DIY fitment. Every system carries a lifetime guarantee, making a stainless system a worthwhile long-term investment over mild steel, which is susceptible to corrosion and typically requires replacement every few years, particularly on cars driven through winter or stored in damp conditions.
Chrome Bumper vs Rubber Bumper
As with all MGB exhaust systems, the chrome bumper and rubber bumper distinction applies across the entire stainless range. This reflects the change in centre silencer type that occurred at the start of rubber bumper production in 1974, when the original flattened oval section centre silencer was replaced by a crimped box type. The rear silencer, twin downpipe layout, and left-hand side tailpipe exit remained the same throughout production, so when ordering it is essential to select the correct system variant for the car.
Complete Systems
Four complete system types are available. The standard system offers a direct replacement for the original exhaust layout using standard-dimension pipework and silencers, compatible with existing OE mounting kits. The bomb box system substitutes a bomb-style centre silencer in place of the standard box, while the slimline system provides a space-saving alternative for owners with ground clearance concerns or those running lowered suspension. The Sports Free Flow system incorporates a smaller centre box and twin polished tailpipes, designed to reduce back pressure for improved exhaust gas flow and a modest increase in power output.
Performance Packs
For owners seeking a more comprehensive upgrade, complete performance packs combine a gas-flowed stainless tubular manifold with a full exhaust system, available in standard box, bomb box, free flow, and big bore configurations, each offered in both chrome bumper and rubber bumper variants. The performance manifold is also available separately, designed to couple directly to an existing exhaust system for owners who want improved gas flow at the manifold without replacing the entire system. The big bore performance pack uses 2-inch diameter pipework with a single rear silencer, intended for fast road and track use where maximum flow is the priority.
Supersports & Individual Components
Supersports rear silencers featuring 3-inch diameter rolled edge tailpipes are available individually in single and twin tailpipe configurations, finished in mirror polish stainless steel, and can also be specified as part of complete performance packs. Individual stainless components are available separately, including the header interpipe and rear box combination.
When fitting any stainless system, the correct exhaust fitting kit should be selected to match, standard dimension systems, free flow systems, and performance packs each having dedicated kits covering the relevant chrome bumper and rubber bumper applications, listed in the Exhaust Fitting Kits section and providing all clamps, mountings, and fixings required for a complete installation.
The Double S Lifetime Guarantee
MGOC Spares has worked in partnership with Double S Exhausts for over forty years, and in that time thousands of Double S systems have been supplied to MG owners across the UK and around the world, every one backed by the Double S Lifetime Guarantee. The combination of premium British stainless steel, expert hand fabrication, and decades of refinement means these systems are built to outlast the cars they are fitted to, and on the rare occasions when an issue does arise it is treated with the same care as the day the exhaust was first supplied. Rear silencers have been replaced on the strength of receipts dating back decades, a recent example being one first supplied in 1991, honoured from a handwritten receipt kept for over thirty-five years. MGOC Spares stands behind every system supplied, not just on the day of purchase but for as long as that exhaust is on the car.