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New exhaust is in-tune with 3 cylinder engines

The R&D team at Klarius has developed a new replacement Citroen C1 exhaust that offers a marked improvement over the OE item, both in terms of robustness and noise reduction. The replacement, among other features operates 1dB quieter when compared to the OE in tests, which is a highly desirable in 3-cylinder cars.

“More importantly,” States Doug Bentley, Klarius Group Head of Product Development for Emission Control Products, “the ‘note’ for the exhaust is much improved so subjectively we have made a system that is both quieter and more appealing to driver perception.”

The huge increase in 3-cylinder engines being used in passenger cars is being driven by demands for better fuel economy and reduced cost, both to manufacture and maintain. Although the design has been around commercially for a long time, with various manufacturers such as Daihatsu, Suzuki and Chevy in the US using them, they only truly reached mass market use in Europe with the small eco-cars such as the Smart, VW’s Lupo and more recently Toyota / PSA shared platform models including the Aygo and C1.

One of the key problems with the three cylinder four-stroke engine is that it is inherently unbalanced and tends to produce a lot of vibration in use, it’s also noisy. Most current 3 cylinder engines employ balancer shafts to counteract the engine vibration*, but on early cars there was an issue with internal exhaust baffles coming loose on some of the PSA vehicles.

The new Klarius exhaust, UK product number CN549J, has been designed to address the issue with the baffles on OE items, with a more robust design and internal welds for durability.

“This also gave us the opportunity to ‘tune’ the exhaust at the same time,” Explains Doug Bentley. “We always test noise as part of the development work we do on each new exhaust design, and it is independently witnessed by a VCA engineer during the type approval test**, carried out at the Klarius test track.

“What we have been able to do is work on the gas flow within the silencer and gain a more appealing note to the exhaust in addition to controlling the noise from the engine and carefully matching back pressure to ensure maximum performance and economy. During the development we focussed our efforts on reducing the low frequency drone this vehicle suffers from”.

The replacement C1 exhaust design has full government type approval (as do all Klarius exhausts) providing total customer reassurance that they are buying a quality product that will maintain the economy and reliability of their vehicle. There has also been a lot of work done to ensure the fit and profile of the replacement is super accurate, as there is often little room to work on compact cars such as this and tolerances have to be extremely tight.

The entire Klarius emissions range is included in comprehensive paper catalogue format, electronically on Tec Doc and for all customers via the new Klarius Group online product catalogue at