Valved Exhaust System for BMW i8 I12 / I15 1.5T (2014-2019)
Configuration
BMW i8 I12 / I15 1.5T Valved Exhaust System (2014-2019)
Valves
Operated by remote control, factory-paired.
Estimated at 0.50 m from the outlet, 45°, 2,000 rpm with a warm engine. Allow ± 2 dB depending on the engine and measuring point. A 3 dB difference is audible in a direct comparison; 10 dB sounds roughly twice as loud.
Configuration guide
Sound intensity with the valves open, on a scale of 0 to 10.
| Configuration | Intensity |
|---|---|
| Decat downpipe + Rog cat-back | 10/10 |
| 100-cell sports catalytic converter + Rog cat-back | 9/10 |
| 200-cell sports catalytic converter + Rog cat-back | 8/10 |
| Rog cat-back only, factory catalytic converter retained | 7/10 |
| Factory exhaust, for comparison | 3/10 |
The BMW i8 I12 / I15 exhaust in detail.
Butterfly doors and a concept-car silhouette: the i8 looks like no other car. Behind the passengers, mounted mid-rear, a 1.5-litre turbo three-cylinder drives the rear wheels with 231 hp and 320 Nm, while an electric motor powers the front axle. The whole package develops 362 hp and 570 Nm from 2014 to 2017, then 374 hp from 2018, in both Coupé and Roadster form. Our page describes it from 2014 to 2019.
A three-cylinder has a singular voice, hoarser and more rhythmic than a four-cylinder, almost rough, which contrasts with the i8’s futuristic image. As standard, you only perceive an echo of it, as the standard exhaust is designed to keep the combustion engine in the background even at full load. With the valves open, the Rog cat-back lets you hear that grain with every acceleration; with the valves closed, the i8 keeps its restraint to cross town.
As the engine sits behind the cabin, the system is short and compact; built to your VIN, it attaches with clamps and gaskets, without welding, in about two hours, and leaves the hybrid drivetrain untouched. The valves respond to the factory control or to the Rog remote.
The “Manifold” option sells the three-cylinder’s downpipe, with its catalytic converter; fitted on its own, it only brings sound and a little lightness, and power requires an ECU remap entrusted to a tuner who knows hybrids. A hybrid of this generation is best kept with 200 cells, which leaves the three-cylinder’s emissions control in place; the 100-cell is accepted or not depending on the car and the rules in your country, and the decat version is reserved for track use. On a car so conscious of its mass, titanium, around 40% lighter than 304 stainless steel, makes sense.
BMW i8 I12 / I15 1.5T exhaust specifications.
| System type | Valved cat-back (valve exhaust), built to your VIN |
|---|---|
| Vehicles and chassis codes | BMW i8 I12 coupé and I15 Roadster |
| Engine | 1.5-litre turbocharged three-cylinder, 231 hp and 320 Nm, 362 then 374 hp with the electric motor |
| Years | 2014-2019 |
| Materials and finishes | 304 stainless steel or titanium; titanium in brushed, gold or purple |
| Valves | Factory valve control if the car has it, otherwise the Rog remote |
| Front section (option) | Downpipe with 200-cell or 100-cell catalytic converter, or decat |
| Fitting | Clamps and gaskets, no welding, about 2 hours |
| Manufacturing and delivery | Made to order, 20 working days, free delivery |
| Warranty | 3 years, parts and workmanship |
Questions about the BMW i8 I12 / I15 1.5T exhaust.
Can the i8 Roadster take the same system as the coupé?
Yes. The I12 coupé and the I15 Roadster, launched in 2018, take the same Rog system, with the same clamp-and-gasket fitting. Your VIN is only used to confirm the version before manufacturing.
Can the i8’s three-cylinder be remapped?
The page publishes Stage 2 figures of 274 hp and 399 Nm for the combustion engine alone, with downpipe and map; on a hybrid, this work calls for a tuner who masters the whole system, and the cat-back on its own does not touch it.
BMW i8 1.5T with a Rog exhaust: what should you know about vehicle inspection?
With the valves closed, it stays as discreet as it was from the factory, and its catalytic converter keeps working behind the cat-back alone or the 200-cell downpipe; a 100-cell is accepted or not depending on the vehicle and your country’s rules, and the decat version is reserved for track use.
In electric mode, does the i8 stay silent?
Yes, since the three-cylinder is then switched off; our system only speaks up when it starts, and the front electric motor and the battery stay exactly as BMW designed them.
Can a three-cylinder give the i8 a fine voice?
Yes, a gruff, rhythmic voice, unexpected on such a futuristic car; with the valves open, it accompanies every acceleration, with them closed, it fades away.
BMW i8 I12 / I15 1.5T: Does a valved exhaust system drone?
No. With the valves closed, the gases flow through the whole rear silencer and the cabin stays calm at a steady speed. Our Rog exhausts are designed to avoid drone. Learn more: Why our systems stay calm on the motorway.
BMW i8 I12 / I15 1.5T: straight pipe or resonator?
On this model, two characters at the same price: the straight pipe for the raw sound of your engine, unfiltered, or the resonator for a rounder and slightly softer voice. Either way, the exhaust stays fully sporty. Learn more: Exhaust resonator: what does it do? Straight pipe or resonator, which sound to choose.
Rog expert guide
BMW i8 I12 / I15: the three-cylinder hybrid sports car, the exhaust guide
With its butterfly doors and concept-car silhouette, the BMW i8 I12 / I15 looks like no other car. Behind the cabin, a 1.5-litre turbocharged three-cylinder works in tandem with an electric motor. But the factory exhaust is designed to keep...
In detail
Rog Advisor
A question about this exhaust?
Fitment, sound, catalyst, valves, delivery: the answer comes straight away, with your configuration in context.
The Rog Advisor is an automated assistant trained on our product pages and answers. For an important decision, write to us: we confirm by e-mail.
Unsure about your configuration? Talk to us before you order. We know your car. Write to us at contact@rogmotorsport.com: we reply in writing, in English, within 24 hours. Email us
Reviews imported from our previous system and translated from French; verified purchases carry the badge.
Rog presentation film: choosing your vehicle, Standard or Equal Length design, stainless steel or titanium, Z-Pipe, controlled valves, titanium and tip finishes, and support from choosing your configuration through to shipping.
THE Rog CRAFT
Our process.
From the first bend to the last check. The same care at every step.
-
Design
Designed for your vehicle.
Geometry matched to your model, carefully studied bends and precise mounting points. Everything starts with accurate design.
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Manufacture
Crafted with precision.
Tube bending, part fitting and TIG welding: every joint receives the same care.
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Finishing
Material, elevated.
The finish reveals the character of the metal. Stainless steel or titanium, depending on the options available for your vehicle.
-
Assembly
Every part in its place.
Components are assembled and adjusted. On valved systems, the mechanism is fitted, set up and tested.
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Inspection
Check. Then approve.
Geometry, welds, connections and gas flow: the key points are inspected before shipping.
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Shipping
Ready to join you.
Reinforced packaging protects your exhaust in transit. The final step before giving your vehicle a new voice.
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