The TSL Group N exhaust for the Subaru Impreza is quite a revered choice when it comes to ‘standard-looking’ backbox options. Not too flashy, and not as antisocial as something like a Nur Spec or Afterburner exhaust.
Very similar in size and shape to the Prodrive backbox offered with the PPP (Prodrive Performance Pack), it’s quite a common choice when looking for top quality, subtle exhaust modifications.
Although more than happy with the sound and looks of my existing Prodrive backbox, I’d heard great things about the TLS Group N and wanted to try it out.
Unfortunately it’s no longer being produced (TSL Motorsport no longer exists), so the only chance of picking one up nowadays is through the classifieds and auction sites. I found my 2.5″ TSL Group N backbox from a seller on eBay for around £70 delivered.
It’s quite hard to find any direct information about this backbox, but scouring through some old archived websites I managed to find the blurb explaining the Group N from the old TSL Motorsport website:
TSL Group N Spec. Rear Silencer
The TSL Motorsport rear silencer is constructed to exacting Group N specifications – precisely what you’d expect from a company with our rallying heritage.
Available with either twin 65 mm or a single 90 mm polished outlet, hand-fabricated from finest quality 304/16 gauge stainless steel, and guaranteed for the life of your vehicle. Uniquely, the homologation-style fixings mount the unit in place with rally-spec. R clips.
Not only does this exhaust look different from others, it also has a unique and distinctive sound quality. The slightly harder exhaust note provides a thrilling, full-throttle Group N sound track which isn’t intrusive from inside the car. The noticeable gains in throttle response and torque are precisely what you would expect from an exhaust of this quality.
- Originally from this archived link
Unwrapping the package I found the backbox to be in pretty good condition, considering they spend their life inches away from the ground and are now getting quite old.
But there’s always time for a little improvement. So out came the soapy water and the trusty Autosol metal polish for a quick scrub up.
Not bad! The flange on the connecting end had seen some heavy corrosion, so I grinded that down as as best as possible using my trusty Dremel too.
I then sourced a decent 2.5″ gasket kit, including nuts and bolts, ready for fitment.
One trip to my local garage later, and it was fitted! Luckily fitting a midpipe (centre section) or backbox doesn’t warrant a remap, so you’re free to swap between these exhaust components with ease.
BUT, and this is a big but, I wasn’t very impressed. Through no fault of the TSL Group N backbox itself (you’ll see what I mean soon) – it just didn’t sound as good as my previous Prodrive backbox.
Watch the video, and you may be a little underwhelmed yourself. It certainly had a different tone to the Prodrive backbox, but it just wasn’t as loud or as guttural.
But the reason for this was evident upon taking the car to the garage. Little did I know that at some point in its lifetime the existing Prodrive backbox had been butchered. As you can see…
This meant the baffles had been removed, so the sound that my car produced wasn’t even the sound it was supposed to. I’d grown so used to this overly loud baffle-less exhaust, that fitting the TSL Group N was naturally quite underwhelming.
Here’s a post about the saga of this Prodrive exhaust: