Owners say all the aftermarket systems are expensive for what they give, and that on a four-cylinder car "no matter what you do it's not brilliant, just louder". This page collects what they say about noise. Figures are owners' own readings, taken on different cars and meters.
Loudness, in one owner's order
From a 2016 thread, quieter to louder: standard (quiet), Milltek (a bit louder), Larini (loud), VSE ("mental"). He adds it depends on the engine and induction combination. Others:
- Larini: one owner followed a Turbo with one through a tunnel and said it sounded as good as any he had heard on a VX: quite loud, but good. Two others like the "burble" around town. One owner who has run a VSE, a Milltek and then a Larini on later cars says the Larini comes out top for him. Another says it prevents him from most UK tracks nowadays, at 101 dB on his last track day, and wants to sell it. A supercharged owner who tried one said it was too much: over 105 dB.
- VSE: one owner says it frightened small children at 1,000 yards on a supercharged car, though another owner's VSE on his first NA "did pass noise tests on trackdays". One owner fitted one to a supercharged car with the standard manifold and the pre-cat removed, and liked the bangs and pops.
- Milltek: one supercharged owner says a jet-fighter noise with minimal drone when cruising. Milltek no longer make one for the 2.2, one owner says, but the Turbo one fits if you can find it. A Milltek VXR backbox on a Turbo is an absorption type (see below).
- Janspeed: one owner says his is not as loud as a VSE and close to a Milltek. Another says Janspeed make one similar to a VSE, but with a minimum order of five; someone tried a group buy ages ago.
- Prospeed: one owner who inherited one says it gives a burble round town but doesn't deafen you on the motorway, with a track-day noise reading of between 91 and 95 dB.
- Piper: one owner says they are quite loud.
- Tullet 3 inch system: one owner who had one said static it was 92 dB at 4,000 rpm; another says a Tullet 3 inch system is extremely loud on a high-power supercharged car. For a road Stage 2 supercharged car that owner suggests a Turbo muffler with a bigger-bore downpipe.
- Standard Turbo backbox: one supercharged owner tried a Dbilas manifold and downpipe with a VSE (louder), then a Larini (too loud) and went back to the standard Turbo backbox, which he calls the perfect compromise: reasonably good sound, under 90 dB, and enough for about 260 bhp. Another owner's supercharged setup (Tullet manifold, standard downpipe, cat removed, Turbo U-bend and backbox) measured 89 dB at Coombe.
Why bigger isn't always quieter
- One owner explains that the standard NA and Turbo backboxes are chambered: the gas passes through several chambers that cancel the noise.
- A Tullet backbox is an absorption type: a perforated straight pipe wrapped in absorbent wool. These are louder than chambered ones, and the wool breaks down over time.
- One owner with a Milltek VXR absorption backbox on a Turbo says he has to repack it every 10,000 km, and that nothing lasts long. He says if you go this way, look for a silencer that screws apart, as opposed to one you open with a grinder and re-weld.
- Another owner says the Tullet is the only one he knows of that can be opened, and that Tullet's U-bend meets the cat section flange a few degrees off compared with the other makers, so you would have to modify it to mate to anything but a Tullet cat. A second-hand box was re-welded for about £20.
Intake noise counts at a track noise meter too. One owner says the standard filter box is very quiet and capable of 250 bhp, whereas an open cone is much noisier, though a lovely sound for road use.
A full replacement system in 2021
An owner of a nearly 20-year-old NA whose engine light came on, with a faulty cat according to the code reading and a slight leak at the cat-to-silencer joint (crudely repaired), got three quotes for a whole system and new lambda sensors:
- A tuner: £1,176 (not including a pre-cat).
- A different engineering firm, which was said to have acquired the original maker's jigs and drawings: £1,136.
- An Elise parts supplier: £1,260.
One owner had a full 2.5 inch Tullet system (header, cat and backbox) and is very happy with it. The thread doesn't record which the poster chose. For lambda sensors see Post-cat lambda sensor replacement.
Help wanted
We don't have readings from a single meter for different systems, or current prices. If you have measured the noise of your system, please tell us what you have and how you measured it.