AER P32T V8

Tag : Electrical Motor Bearings

Endurance racing brings its own set of unique challenges for enginedesigners that make F1’s two races per motor rule look tamein comparison. Three, 12 or 24-hour races, a variety of differentdrivers per car and balancing the need to go quickly with thedesire for reliability are all important. And so, given thedisparate nature of the two discipline’s technicalrequirements, it’s all the more interesting that a new,independently designed, 3.6-litre, twin turbo V8 sportscar engineincorporating grand prix-style technology is starting to deliverreal results in the LMP1 category of the ALMS and LMES.
The company behind the project is UK-based Advanced EngineResearch, a firm with a great track record, but with even moreambitious plans to shake up the sportscar establishment in 2006.With just 29 employees, AER is Minnow-like in comparison to thelikes of Audi Sport, but a combination of the new V8 and a decentchassis has the potential to become a real threat to the AudiTDI-mounted opposition.
Earlier in the year, at Sebring, an AER-equipped Dyson Lola BO6/10qualified a mere 3.8 seconds behind the oil-burner, only a late lapsuspension problem keeping the team from a well-deserved podium onthe engines’ promising, but frustrating, LMP1 race debut.Pre-season testing had also proven the new units’ power whenat Paul Ricard it provided enough urge to clock the fastest topspeed along the Mistral straight, fitted in the Synergy Lola.
What makes the story behind the new engine all the more remarkableis the fact that the new AER V8 ALMS engine was designed and builtfrom scratch in just nine months by a small team lead by OliverAllan, technical director of AER, who previously worked at Ilmor.

Clean sheet approach
LMP1 racing is dominated by ex F3000-based motors and down tunedIndyCar engines or, as AER’s managing director Mike Lancasterputs it, ‘Old Formula 1 engines... but they’re big,heavy and not very fuel efficient, so we saw a potential gap in themarket.’
Plugging that gap with a lightweight, small, efficient unitincorporating F1 technology would have been a relativelystraightforward task for a manufacturer-backed concern, but todeliver a cost-effective powerplant capable of taking on theALMS’ big guns and yet remaining affordable to independentsproved more of a juggling act.
‘I wanted it to be the smallest, lightest and most efficientsportscar engine out there...’ says Allan, ‘...and onethat fitted into a smaller space than anything else and one thatstructurally used the metal in it more efficiently. And we’vehit every one of those targets.’ Achieving these design goalswhile maintaining the viability of the business case has been downto the cost-effective use of F1-style technology and techniques,rather than throwing exotic materials at the engine to drive downits mass and size. ‘Coming from a Formula 1 background peopleexpect it to be the most expensive engine in the world, butit’s not,’ Allan explains.
That’s proven by the fact that there are no rare metals inthe engine, just conventional alloys and steels, allied to a carbonfibre inlet system. Yet complete with twin turbos, ECU and wiringloom the AER V8 tops the scales at a featherweight 110kg dry.It’s compact too, at just 590mm wide, 580mm tall with inletsystem and 503.2mm long, making it shorter than AER’s currentfour-cylinder LMP2 engine, and it’s been designed with enougharchitectural flexibility that it can be used in non-sportscardisciplines. Mike Lancaster explains: ‘If you took therestrictors off, it was designed to be a 1000bhp+ unrestrictedturbo engine or a normally aspirated motor.’ So, small yetvery strong, what secrets lay within the AER V8’s detaileddesign?

Key architecture
Turbocharged LMP1 engines run air inlet restrictors and a strictboost level cap, which sets the ultimate amount of air they canpump and therefore provides a theoretical power ceiling. Huge leapsforward in brake horsepower and torque are not the nature of thegame, so a different design approach is required from the outset tomaximise performance. ‘Your ultimate power level is prettymuch fixed by those factors, so all you can do is try to minimiselosses and improve combustion efficiency. A lot of the engine isreasonably conventional, but it’s the details that make itwork well,’ says Allan.
And that detail design approach began with the alloy engine block.On the face of it there’s nothing radical here, as the V8uses a steel linered, wet deck design split at the crankcentreline. On a micro level, matters get far more sophisticatedand confidential within the Zeus casting, as Allan explains:‘The sort of features within it make it very light and thestructure is more thought about than most engines, I suspect. Thatallows you to use a small amount of aluminium rather than making itbig and heavy.’ Even so, cost considerations drove theadoption of steel liners and Allan reckons that AER could shaveanother 10-15kg from the engine given a larger budget to play with.
Physically, the V8 uses a rather narrow 75-degree V angle, comparedto the more normal 90-degree figure. The block stiffness wassufficient to retain torsional rigidity of the motor at this angle,which provides benefits, particularly in turbocharged applications.‘With the tunnels that they’ve got on the LMP1 cars theturbos have come up anyway, so narrowing the V angle helps withpackaging the exhausts,’ Allan comments.
Particular attention has been paid to keeping the mass within theengine as low as possible, which has resulted in a very low centreof gravity for the unit. ‘It has the lowest crank centrelineof any of the sportscar engines,’ says Allan, ‘and theonly reason that it isn’t lower is because no one wanted totake on board the cost of developing a smaller AP Racingclutch!’ This episode highlights the potential limits forsize reduction in LMP1 engines for independent teams before it hasa knock-on effect in other components. Besides, as Mike Lancasterpoints out, ‘Sportscars are fundamentally large and theengine is very small in the back, so the question was how muchsmaller did the customers want to go?’
Finally, but crucially, the bore/stroke ratio of the motor helpedto dictate the layout and footprint of the V8’s block. For anendurance engine, keeping piston speeds down offers wear andfrictional loss benefits, so a short stroke is the norm, but Allanthinks that the new engine may have taken this concept furtherstill. ‘We’re quite oversquare for this category, butnot compared to a contemporary F1 engine. As with all factors,you’re always playing the balance, but I think thatwe’re in the ballpark.’
Even so, at 3.6 litres the unit has a fair degree of flexibilityfor capacity increases. ‘It can go to 4.0 litres as asportscar engine, but it could go bigger if required, particularlyif normally aspirated, where cylinder head sealing isn’t ascritical as with a turbo application,’ Allan reckons.
The heart of the AER V8 is a ‘pretty conventional’ flatplane steel crankshaft, produced by Mecachrome in France. With thegoal of frictional loss reductions in mind, the crank runs in smallbearings and has been designed to use what mass it carries tooptimal effect, where it hooks up to steel connecting rods fromPankl and pistons from the same supplier.
Topping the engine are a pair of four-valve cylinder heads,designed carefully to optimise combustion efficiency, although AERunderstandably wouldn’t comment on valve sizes and angles.Lancaster and Allan were, however, happy to confirm that thecombustion chamber has been designed with direct fuel injection inmind, a subject we’ll return to later.
Likewise, aside from revealing that the unit runs gear-driven cams,the detail on the valvetrain of the AER V8 is going to stay underwraps for the duration. ‘It’s all been donebefore,’ says Allan, ‘but outside of sportscarengines.’ You can forget any ideas of pneumatic valve systemstoo, as this method of valve actuation was dismissed on arelatively low-revving engine where wire springs function perfectlywell. Finally, a major consideration is that LMP1 engines work hardin an environment far dirtier than an F1 motor operates, whereaspneumatics require a clean environment to function reliably.
The philosophy of performance through efficiency was carriedforward to the lubrication and water systems on the car. The formerruns a dry-sump system, using ‘as little oil as possible– it has a significantly low oil and water flow,’according to Allan, although he wouldn’t be drawn on details.
One thing that we can be certain about is that the oil and watersystems feed a pair of Garrett motorsport-specification turboswhich, in accordance with LMP1 regulations, use fixed geometrysteel internals. Running 32.4mm inlet restrictors and a boost limitof 1.67bar, these breathe through a pair of conventionalintercoolers, as per LMP1 regulations, so there’s littlescope for design latitude here.

Pushing the boundaries
Where AER has pushed the boundaries on the engine is in the realmof electronic control. AER’s in-house electronics division,Life Racing, worked in close conjunction with the engine programmeto develop an advanced level of electronic control over everypossible parameter on the engine. For example, the throttle systemworks using port pressure measurement as a parameter, whichentailed positioning sensors at suitable locations in the engine.It is areas such as this where Life Racing and AER working underthe same roof has reaped benefits, allowing AER to ‘punchabove its weight’ technically.
Another case in point is that the induction system on the new V8has been designed at the outset to operate via drive-by-wirethrottle control, which requires motors and drivers and associatesensors. It sounds complex, but AER claims it simplifies matters,particularly when working in tandem with a semi-automatic gearboxcontroller that, on the Dyson Racing car, operates a Dyson-Lolagearbox with Hewland internals. ‘It’s the firstdrive-by-wire engine AER has designed from the outset,’ saysLancaster ‘and we’ve developed that a huge amount overthe last six months into a system that’s small anddoesn’t use much power.’ It’s also neater thanbefore, because the four-cylinder LMP2 engine uses a mechanicalthrottle with an electronic ‘blipper’ on the downshift,further complicating the control mechanism.
Interestingly, drive-by-wire opens up a number of interestingpossibilities on throttle control, as Allan explains, ‘Youcould open one bank of throttles before the other for example, orcontrol them independently, so we’re just scratching thesurface of what we could do with this engine.’ Thisdevelopment potential is thanks in small part to the Life RacingECU, which has been designed specifically with boost and knockcontrol strategies in mind for this application. It uses threeMPC565 controllers to run the engine, plus a separate gearboxcontroller, which is integrated into the F90 ECU package. Usingseparate Lambda controllers for each bank of cylinders, Lancasteris confident that the ECU is pretty much state-of-the-art,particularly for turbo applications. ‘I don’t thinkmany people run the advanced knock control that we do, with thepossible exception of Audi. We try to make the engine run on aper-cylinder basis as well as it can. As a result you have todevelop strategies that control the absolute quantity of ignitiontiming, rather than just removing it when the motor knocks.It’s an active system and it’s proved to be rugged andpretty effective.’
At present the Life Racing F90 ECU controls two injectors percylinder, one being mounted in the inlet tract and one positionedfurther up the induction system. With a direct injection upgradeplanned in the future the fuelling arrangement will simplifyfurther, running a single injector directly into the combustionchamber via a machined boss. ‘Although the unit is very fuelefficient at the moment, switching to direct injection willdefinitely offer an advantage,’ says Lancaster.
Cleverly, the ECU has been designed around an electronic wiringsystem that incorporates a solid-state controller for the engineand car functionality. Called a Power Distribution Unit (PDU) thiscontrols the starter motor, lights, wipers etc and removes anyrelays, fuses or circuits breakers from the car and engine, asidefrom those that require manual operation. It controls everythingelectronically and has current limits and measurements on everycircuit, with up to 32 channels of operation, each capable ofdriving 45amps. By sensing faults and trying to solve them, whilealerting the telemetry as it talks to the ECU, the PDU not onlysaves the weight of having to lug around relays, it simplifies thetelemetry by trying to solve faults independently of an electricalengineer.

Performance and durability
With the mapping and endurance testing carried out on AER’sin-house dyno, the V8 LMP1 engine ran for the first time in car inthe back of the Dyson-Lola in late January 2006. Niggling problemsaside, the engine has proved reliable and fleet, producing aprogressive power curve with good low-speed urge. Running to7500rpm, with an 8300rpm soft cut, Lancaster says that drivers havebeen very positive in feedback on the new motor, describing it as‘like a big N/A engine, with real throttlecontrollability.’
Much of the credit for this benign power delivery is linked back tothe design of the electronics, particularly boost control.‘There’s a lot of detail work on the actuators andturbo controllers to ensure that the boost curve is maintainedduring throttle-on/throttle-off situations,’ Lancasterconfirms. This effort seems to have paid off handsomely,particularly bearing in mind that the engine raced at Sebring isessentially, as Allan describes it, in ‘fire-up’specification. ‘So far we haven’t explored theperformance potential of the engine at all, but we’ve starteda bit of this in the last few weeks and we’re getting goodperformance gains, as you’d expect because you need to beconservative at the start of a programme.’
Without the luxury of a manufacturer’s marketing programme tohelp development, scope for testing is sometimes limited. ‘Wecan do endurance testing on the dyno, but it’s a bigundertaking. A 24-hour race simulation costs thousands of pounds infuel, and even dealing with the physicality of the test isdifficult. Dyson Racing is prepared to do circuit testing, but evenso we’re going to do a lot of dyno testing.’
Early indications are extremely positive for the AER V8 LMP1 motor.‘The reports that we’ve had so far indicate thatwe’ve been successful in that because we are more fuelefficient and we’re producing more power than weexpected,’ says Allan. Customers so far include Dyson Racingand Chamberlain Synergy, plus privateer Paul Cope, with Dysontaking the fight to the Audis and Porsches at Sebring, where AERwas unlucky to not get a podium with the new powerplant on its racedebut. ‘One of the cars picked up a plastic bag in theradiator and retired as the engine ran too hot for too long. Wewere running a strong third in the other Dyson car, but they brokea floor late in the race. Still, we did more racing miles thanPorsche or Audi and, considering that this is a small company incomparison, we’re pretty pleased,’ smiles Allan.
And indeed he should be. Introducing an engine into a conservativecategory is never as easy task, yet AER’s innovative approachseems to be paying dividends.
But given the technology involved in the engine, what are theimplications of running such a modern, up-to-date unit? Rebuildintervals are 3500km for sprint race use, rising to 5200km for the24 hours, while the V8 motors aren’t for sale asthey’re available on a lease package only. It’scertainly a tempting package for ALMS / LMES competitors, whichexplains the high levels of interest and the enticing prospect ofthe unit appearing in the rear of the Radical SR9 chassis later onin 2006. As Allan says, ‘The philosophy of getting all thedetails right has paid off.’