Saturday 17 August 2013

BBR Turbo Conversion

Back in the early 90s a British company by the name of Brodie Brittain Racing (BBR) founded by Dave Brodie and Ken Brittain, produced a turbo conversion kit for the 1.6 NA Roadster. The conversion was fitted at dealerships and approved by Mazda with the added benefit of a 3 year warranty. Fitting a turbo to the little roadster boosted power from 114Bhp to just over 150Bhp with torque jumping from 100lb/ft to 154lb/ft, this was enough to propel the car to 60mph in 6.8 seconds. There were other options available too including 15" OZ alloy wheels, a limited sip differential, Finish Line bodykit (as seen on the Le Mans special edition), and believe it or not, a flying helmet complete with goggles for roof down adventures. Overall it was a great package and is still sought after to this day.

The original BBR Turbo kit

The original BBR conversion was the closest we would get to seeing a factory turbo roadster for the NA generation. It took a long time before Mazda experimented with turbocharging the MX-5 again. That's not to say that turbos fell out of fashion, there were many aftermarket tuners providing kits to boost the roadster engine, Flyin' Miata and BEGi in the USA, HKS in Japan for example. But it took around 14 years for a factory model to appear. In 2004, towards the end of the NB generation Mazda introduced the Roadster Turbo.

This model was available in Japan and based on the 1.8 NB2, it used the earlier BP-ZE engine rather than the BP-VE engine with variable valve timing. In standard tune a 2004 1.8 would have produced 160PS @ 7000rpm, the turbo model received a mild boost and was rated at 172PS @ 6000rpm. This may not look like much of a gain, but importantly peak power comes in earlier in the rev range and torque jumped from 170Nm @ 5500rpm to 209Nm @ 5500rpm. The turbo model also had a unique front and rear spoiler and 17" Racing Hart branded Enkei wheels. Roadster Turbo was also sold in the USA where it was marketed using the Mazdaspeed brand. Australia also got factory turbo models, but for some reason they were never offered to the UK market.

I was excited to hear then that BBR are working on a UK turbo conversion kit for the NC generation. BBR are already offering various upgrades, including the "Super 180", and a Cosworth supercharger conversion, but it's great to see turbos returning and with full UK support. BBR say they want to create a turbo kit that looks as if it was fitted at the factory, this basically means they want it to be so well designed that it looks as if it was supposed to be there and not something that is just stuck on as an afterthought. In terms of numbers, BBR say:
"Peak power is 248 BHP (220 BHP at the rear wheels) running at a mere 0.4 bar boost pressure (less than 6Psi!) This equates to a 20 BHP mid-range gain when even compared to BBR's Stage Two supercharger conversion (with full BBR exhaust system running 0.7bar/10Psi), this highlights the efficiency of BBR's turbocharger design."
It's an impressive boost and there is much more potential in the MZR engine to easily see over 300Bhp. The main components of the kit are as follows, though there are no details yet on what's being done for engine management.
  • BBR Garret GT series internally wastegate turbocharger (350BHP capability)
  • BBR Cast T25 manifold – stainless tubular option
  • BBR stainless steel downpipe
  • BBR highflow aluminium intercooler pipes 2.25" hot side 2.5" cold
  • Front mounted intercooler – highly efficient Garrett core option
  • Recirculating dump valve (cold side)
  • 2.5 bar MAP sensor with inlet temperature sensor moved to inlet manifold (from MAF)
  • BBR high flow air box cover
  • Bosch high flow EV14 injectors
BBR NC turbo kit prototype
You can read more on the upcoming kit on BBR's site. In terms of pricing, I'd estimate similar to their supercharger conversion so in the region of £5000. The kit is currently undergoing tests for reliability and durability but should be available soon, in fact there is supposed to be an announcement sometime in September 2013. No word yet on whether the flying helmet will be making a comeback...

Update: According to Neil at BBR, the Stage 1 DIY turbo kit will start from £4395.

Update: You've seen the above prototype, here is the production version with optional carbon fibre components. The battery cover doesn't quite fit and has to be removed but otherwise the conversion looks like original equipment.
BBR have also recently announced a "GT270" turbo conversion which features a programmable ECU allowing the driver to choose between different performance modes, as well as around 270Bhp. The price point for a new NC3 MX-5 with this makeover is in the region of £30k. This puts it in direct competition with Jota's exclusive 200Bhp GT edition.