RET127 Temp Digital

57 Counterfeit PMWE 2020 Mahle Powertrain (MPT) has some intriguing news for motorsport powertrain professionals working outside of the dizzy heights of Formula One and Prototype racing. Pre-chamber ignition has been central to the development of unprecedented thermal efficiency for the internal combustion engines at the heart of today’s Formula One and Prototype hybrid power units. The use of this approach was first revealed by Ferrari, which confessed to using MPT technology. A comparable technology was used by Porsche in its recent Le Mans- winning V4 turbo, as revealed in RET 124 (February/March 2020). MPT calls its technology Mahle Jet Ignition (MJI). A passive version of the system consists in effect of a tiny pre-chamber housing the spark plug located above the main combustion chamber, and with the passageway between the two chambers taking the form of a plate forming a number of tiny nozzles. The main chamber is either fed fuel via port injection or houses the fuel injector. Either way, on the compression stroke a proportion of the fuel-air mixture is pushed up through the nozzles into the pre-chamber, where it is ignited. Its consequent expansion discharges extremely fast- moving, heated jets back through the nozzles. This provides multiple ignition sites within the main combustion chamber (as controlled by the arrangement of the nozzles). MPT explains that this approach leads to rapid, highly stable combustion with significantly improved knock-mitigation characteristics. The upshot is the potential to use a higher compression ratio and, according to MPT, in its testing a reduction of up to 10% in fuel consumption has been measured. Of particular interest to many motorsport powertrain developers is that the latest development of passive MJI is such that it can be applied to an existing engine with only minimal changes to the final machining process. MPT’s Adrian Cooper, reported, “Continued work throughout the lockdown period means that passive MJI can now be installed as a press-in unit into engines using an M12 or larger spark plug. “We have worked with manufacturers and pinnacle motorsport such as Formula One on the integration of this technology for close to 10 years,” he added. “We are beginning to see jet ignition being adopted in high-end production powertrains, such as Maserati’s recent Nettuno V6. However, our recent work on passive MJI makes the technology more accessible for adoption by mass-produced engines, even as a retrofit to existing designs. “We have also used the opportunity during the pandemic to further develop the cold-start and emissions performance. Through careful development, we’ve been able to engineer a system that operates under these conditions without requiring a second ignition source, enabling the system to be applied to existing cylinder heads without the requirement for costly re-engineering. “We have adapted an MJI-equipped production engine to start, run and perform reliably at -8 C with equivalent catalyst light-off capability to conventional spark ignition. This is very encouraging, and we’ll be continuing development to lower this figure substantially.” Cooper stressed that the key to maximising the benefits of MJI is to understand the vehicle manufacturer’s requirements, and develop the correct combustion strategy accordingly. “While the engineering effort to integrate the MJI system has been simplified, other engine systems need to be further optimised in order to gain the largest benefits, which might include a higher compression ratio, a revised inlet camshaft profile and re-matching of the boosting system. A whole- system engineering approach is the way to get the best from MJI.” MoTeC has released a new product in the form of an M1 integration tool for use with Simulink, which enables the integration of a compiled Simulink model into an M1 control unit. Paul Bower told us, “This feature provides a streamlined pathway from Matlab and Simulink control system development to embedded software for an M1 controller by providing a dedicated MoTeC target to the Simulink code generation. “The tool can be used to develop a complete engine or electric vehicle control system in Simulink or to develop a control subsystem to add additional functionality to an existing M1 package – for example, to add an electric vehicle control module to an existing MoTeC GPR package to develop a hybrid vehicle control system.” New from Pipo Moteurs is a Ford Duratec-based engine for FIA hillclimbing in the up-to 1764 cc category. Frederic Barozier told us, “As the Duratec is well-known at Pipo since 2005 – Focus WRC, Fiesta S2000, Fiesta WRC, Fiesta WRX – it was quite fast for us to develop this hillclimb engine. We did the design assembly and dyno development in few months, at the same time as we were developing a new V8 for Le Mans Hypercar [Glickenhaus will race that at Le Mans next year]. “The first engine delivered has been installed in a brand-new Osella PA 30 T. The first race was delayed until September, and the car only ran a few kilometres before the start, yet the driver Cyril Frantz finished on the podium – a promising start for this new engine.” Barozier reported that the engine is based on the 2.0 litre Duratec using an 85 mm bore, with pistons and liners from the 2.0 litre WRX engine, together with the 73.9 mm stroke crankshaft from the 1.6 litre WRC engine for 1677 cc. Con rods are bespoke to match the combination of piston pin diameter and stroke. The inlet manifold is from WRX, as are the timing drive and valvetrain, albeit with specific cam profiles for high-rpm performance. INSIGHT : PMWE 2020 t Distribution of heated jets through the Mahle Passive MJI nozzles