Spark Exhaust dB Killer Grid-O 35 mm Universal G9989

Thirty-five millimetres of insert that decides whether a Grid-O gets through the gate. Spark's dB killer for its most aggressive silencer family — the part to have in the toolbox before a circuit tells you its limit.

Key Features

• dB killer for Spark Grid-O silencers.
• 35 mm diameter, 100 mm long.
• Listed by Spark for Honda CBR, KTM Duke and Super Duke and Triumph Street Triple applications.
• Removable — fitted and taken out with the silencer in place.
• Not supplied with the silencers as standard.
• Does not change a silencer's approval status.

What It Does and What It Does Not

A dB killer is a restriction placed in the outlet of a silencer. It narrows the exit, which reduces the sound level and raises back pressure at exactly the point the engine is trying to breathe out. There is no version of this where the reduction is free.

What it does not do is change any paperwork. A silencer without an EC certificate does not acquire one because an insert has been fitted, and Spark's own racing silencers stay racing silencers with the plug in. The insert changes what a meter reads, nothing else.

The Right Insert for the Right Case

Spark makes several dB killers and they are not interchangeable. This one is dimensioned for the Grid-O family — 35 mm across the bore, 100 mm long. The Konix Evo and Force Evo cases take the G9999 instead, at 40 mm internal diameter and 75 mm long.

Ordering by silencer family rather than by motorcycle is the reliable way to get it right. A Grid-O on a CBR and a Grid-O on a Super Duke take the same insert; a Konix Evo on the same Super Duke does not.

Why Spark Does Not Include One

Spark's stated aim across its range is to meet circuit noise limits without a dB killer, and its homologated silencers do exactly that. The insert exists for the cases that sit above the line — the Grid-O among them — and for circuits with limits below what any manufacturer designs for.

Keeping it as a separate part is honest about that. You buy it when a specific venue makes you, not because the silencer needed help out of the box.

Fitment & Compatibility

Spark Grid-O silencers. Spark names Honda CBR, KTM Duke and Super Duke and Triumph Street Triple applications specifically. The insert for the Konix Evo and Force Evo cases is G9999; the one for the Force silencers is G9954.

Road Approval

Not applicable. A dB killer changes the measured sound level, not the certification of the silencer it is fitted to.

Specifications

• Part number: G9989
• Type: dB killer
• For: Spark Grid-O silencers
• Diameter: 35 mm
• Length: 100 mm
• Material: stainless steel
• Applications named by Spark: Honda CBR, KTM Duke and Super Duke, Triumph Street Triple
• Road approval: not applicable
• Manufacturer: Spark Exhaust Technology, Mantova, Italy