An Admirable Modern Classic: BMW E31 840Ci

Even by today’s standards the E31 doesn’t fail to impress. With its innovative design and advance features, it is still a match for most modern cars. Having ownership for over 12 years, our customer felt that This 4.4l V8 was in much need of a new exhaust. It was only once when we got under the car did we realise the depth of patchwork and repairs carried out over the years.

All E31s come with a respected Quad Exhaust System that have been set up to be fairly quiet. Having owned some BMWs with the M60 and M62 Engines we were familiar with the kind of setup required for either a loud V8 rumble, a mellow Idle and roar on throttle or an imitation of the quiet setup.

Our valued customer opted for a quiet set up. We immediately started the preparation for the build, starting with making the bespoke Twin Staggered Tailpipes, Bullet Silencers with twisted perforated tube and chambered rear Oval Silencers that we intended to fit on the 840Ci.

Starting from the 2 into 1 pipes on the bottom of the 4 into 2 downpipes we decided to replicate the system in a warranted manner. Stainless Steel M18 x 1.5mm Lambda bosses were machined and then welded into the 304-stainless steel tube.  Followed by a X pipe to help with the scavenging process on the V8.  All of our pipe work has an equal diameter as we strictly mandrel bend only.  The X pipe was designed using 4 mandrel bends all cut precisely so that the flow is equal on each side of the X pipe. A simple test was carried out using air pressure from a heat gun and a light cloth to ensure that the flow is correct.

As per usual we used our in-house CNC Mandrel Bender to form all the mandrel bends and custom pipe work on the E31 BMW. Anyone who is familiar with our unique Bullet design silencers will understand the exclusive proposal we offer and end result. These silencers have been designed to help avoid any unwanted drag or scrapping as well as maintaining a distinguished finish. The internal set up has been design with a twisted/ spiral perf to aid in the velocity of the escaping gases.

Our Oval silencer are made here in UK to a high-quality standard. Being able to make these silencers allows us to choose the setup we wish to have in place on any application. In this case we decided to have a chambered set up to help keep the noise down to a minimal as well as setting the perforated inlet and out as an offset position to help keep a modest clearance from the rear subframe.  The system was built in independent section to allow the buyer to strip the system down whilst servicing or replacing the drive terrain.

We have our own polishing machinery in house to allow us to polish up any dull stainless steel to a high-quality finish. The high chrome finish on the tail pipes were an awesome contrast on the Purple Mora Metallic paint work.  The 80mm Round Twin Tailpipes complimented the final look on this upcoming retro modern classic.  The tailpipes were welded on to staggered 2 into 1 Collector Y pieces which were then neatly welded on to chambered silencer. Once the idle on the car had settled in was pleasing to hear the V8 produce a smooth tone which was not going to be burdening the neighbours. Overall the E31 custom exhaust was an enjoyable build and more we had the opportunity to be privileged to meet the owner of this V8.