The weakest link - New BBR forged components for the SkyActiv 2.0 - 2015 to current 184ps MX-5 model compatibility

New BBR Forged Engine Components For the Mazda MX-5/Miata ND

13th April 2018

It’s safe to say we’ve put more into development and achieved more with the current generation of Mazda SkyActiv G engine than anyone. Way back in 2014 we began development on the current 2.0, turbocharged and developed camshafts before the UK had even seen the current MX-5/Miata ND!

Amazingly the SkyActiv petrol engine has a great deal of misinformation surrounding the tuning and its limitations, still now in 2018! Developing our own forced induction system for this platform it was clear to us we needed to make maximum power gains from the lowest possible boost pressure whilst keeping great torque gains in the low/mid range. Of course, achieving power gains like this is only possible with a turbocharger (not limited to output directly linked to engine speed like a supercharger).

Early developments revealed using a single scroll turbo significantly increased EGT’s and back pressure (this engine’s big enemy hence Mazda’s own 4-2-1 manifolds). We promptly decided to move to a twin scroll unit and never looked back, exceptionally low EGT’s and excellent response, just not possible from a single scroll (ball bearing included). It’s the current choice of Porsche, BMW, Mercedes, VAG, Ford and Subaru – their R&D dramatically outweighs the aftermarket! We believe the BBR ND turbo is the only aftermarket twin scroll turbo conversion for any marque? without a doubt for a Miata/MX-5.

Before the BBR stage one turbo conversion was released, we had tested not just one but three 2.0 SkyActiv engines to destruction. One in our trusty Mazda 3 and two others in MX-5’s! We had also burnt out countless clutches during testing. The result, some of our early turbo road tests had an inappropriate clutch fitted as it was our only option at the time! It was clear with our stage one turbo that we needed to be cautious with its output and unfortunately could not release it with quite as much power as our previous generation MX-5 NC conversion (we know from experience to keep things safe). Engine weakness aside the standard clutch will not take more torque than our stage one conversion. This resulted in our recent choice to use electronic boost control keeping the torque curve flat and peak torque below 230ftlbs.

Below pictures show just some of the dramatic results from 10psi of boost and over! This is the unfortunate reason why we have been holding back with further BBR turbo stages (we have two further engines like this from further stage development). Sadly, the SkyActiv has the weakest connecting rods we have seen! Do not be alarmed, our stage one operates safely at just under 7psi (around 230ftlbs). All in-house failures have been experienced at 10psi or higher (yes this is with safe AFR’s and zero knock, sadly we have another Mazda 3 engine yet to be taken apart with the same issue). Only now we are starting to see claims of around 300BHP from others whilst we have been there and have had the trophies for quite some time!

The good news, we have developed and produced our own parts again, teaming up with a leading European piston and connecting rod manufacturer, we are proud to exclusively announce SkyActiv low compression forged pistons and forged connecting rods. Pistons are available for standard bores and +0.5mm. Our forged SkyActiv conrods are compatible with both standard and BBR SkyActiv forged pistons. Available as a piston and rod set at a reduced combined price or individually, let the next level of SkyActiv tuning begin!

We are delighted to have the parts to consistently run higher power levels (280BHP+) safely and will be shortly launching further BBR turbo stages (currently undergoing vigorous testing).