Spool Time - Part One

Who is Bill Keen?

Bill Keen started an apprenticeship at his family's workshop - Turbo Tune - when he was fourteen. After working there for six years he then went overseas "for a bit of a look" with a guy called Mark Pool - a professional race driver who was looking for a driving career in the UK. The pair stayed abroad for around four years racing cars, test driving and managing teams from Group A to Group N and open wheel formulas. "I got as much exposure as I could squeeze in and I had an absolute ball in the process."

After that, Bill "went with any option that came up." One thing that came up was the responsibility of looking after a C2 Sportscar (from the World Sportscar Championship) along with stints of rally and other varieties of circuit motorsport.

Next, Bill returned to his family's Adelaide business and then - in partnership with Max Heywood who runs Australian Turbo Sales in Melbourne - started up Adelaide Turbo Service. "The business started in 1993 and after two years, my wife and I bought him out and made it our own entity and we've grown it from there." To this date, both Australian Turbo Sales and Adelaide Turbo Service (both abbreviated ATS!) share a close relationship in terms of knowledge sharing and combined buying power.

Aside from doing his apprenticeship, Bill has completed specialist courses on engine management systems and turbocharging. "I've sat and passed an accredited technicians course through the AADS - the Australasian Association of Diesel turbocharger Specialists - plus I've lectured for that association at annual conferences." This in addition to extensive hands-on experience in Australia and overseas.

What were some of the cars you began working on?

"When I did my apprenticeship I was very lucky to start out changing points and repairing carburettors. Turbo Tune - even then - also specialised in dyno tuning, which attracted all of the leading off-road buggies as well as performance road cars, typically with multiple side or downdraft carburettors. So I've had a very good grounding in how to tune vehicles without sitting at a laptop and, as such, I had no problems coming to terms with the operation of the early fuel injection systems to some of today's systems."

"In the early 1980s Mitsubishi was probably the bravest manufacturer locally - they started off with the 2.0-litre Sigma Turbo, which had electronic ignition but still a carburettor. Then there was the injected Cordia and Starion and ET Pulsar - that whole era of small frame turbos on small engines is where it all started."

"It's interesting because turbochargers through the '60,'70s and until the early '80s were mostly diesel. Turbocharger technicians and specialists in this country are predominantly from a diesel background - which is great if you want to make your truck go quick, but when it comes to a petrol engine it's not the best grounding. I think that's where I've had a good advantage - creating a niche market in petrol turbo engines."

Tell us about the engineering of those early mass produced turbocars.

"They were all pretty basic - they weren't even intercooled. The Sigma Turbo, for example, was also constrained with the carburettor - fuel flows were a challenge for some people to sort out. Every vehicle became a progression - in the late '80s we moved on to cars like the VR4, Mazda MX-6/626 and Telstar TX5. There were also a lot of aftermarket turbo kits getting around by this stage - kits for EA Falcons, for example. The VL Turbo, though, was a classic - it really showed the average car buyer that you didn't need a V8 and you didn't need to be making a lot of noise. Not only was it a good standard workhorse but, with a few light modifications, you could add 50 - 60 percent to the performance. It really opened up the market for a lot of people."

What were the first performance mods made to those early turbocars?

"Very typical was an additional injector, so you'd keep the standard idle-up, drivability, air-con idle speed controller and all of those things that the factory does so well - you'd just add a bit of fuel up top. There was also the usual intercoolers, high-flow exhausts and air filters - back then it was Finer Filters and K&N panel filters - and turbo mods meant larger wheels inside the standard frame turbo."

"Second-hand Japanese import intercoolers started becoming popular on the smaller vehicles, but at that time most of the units from Japan were too small - they were also too lightweight in construction to modify. Really, the intercooler market back then was left to companies like AVO - they did a very good job designing and fabricating the necessary products, and they still do."

So what has been the biggest change in the way we now approach modifying a turbocar?

"The biggest single improvement has been the operation of aftermarket management systems and their cost effectiveness. Not so long ago it would have been prohibitive to replace a management system because of the costs associated in achieving something acceptable - we're far less hesitant in that area today."

What is your favourite sub $10,000 second-hand turbocar?

"Well, neat VL Turbos are great but just four grand will buy you a 2.0-litre AS Telstar turbo. The difficulty, though, is that many of these vehicles have been very reliable for 15 years now - they've got to drop eventually. A good condition one is fantastic, but finding one from that '80s era that still has some cooling system life left in it, parts availability and a wiring loom that hasn't gone rock hard is the problem. It's difficult to recommend to someone to go buy one of those vehicles but, for me, the old Telstars are a very comfortable and underrated ol' workhorse."

"The later 2.2-litre turbo Mazdas and Ford Telstars are not bad at all, but they're not quite as appealing to me as the 2.0-litre - the earlier one was a simpler, more reliable and more understated vehicle. The 2.2s also came mainly with automatic trannies, which are expensive to repair. But, like any of those Japanese motors, they'll do easily 200,000 kilometres if maintenance is kept up - but it is very much dependant on that."

And what's your favourite sub $30,000 turbocar?

"I've always liked the 3S-GTE in the Japanese MR2 from the '94 era - they're about 15 grand upward. But for up to 30 grand I guess we're talking later model WRXs and Skylines - I think the Subaru's quality is there exceeding the Nissan's. The Toyotas that we're seeing as Japanese imports - such as Supras - are also very good and you can't overlook RX-7s."

"The WRX, though, has been about 40 grand brand new since they came out - and that's fantastic value. They've really set a benchmark like the VL Turbo did in the '80s; they're a shopping trolley and they've got flaws - nobody will query that - but they're certainly great value for money."

And what are your opinions of European turbocars in Australia?

"In a completely different environment - away from the heat and more in an open motorway environment - they thrive. There's no questioning that they're beautiful comfortable cars, but I don't find them particularly well suited to this country. The Audi I particularly love, but I don't think it's as well suited to our environment as the VL Turbo was - even without an intercooler. Any of that European stuff you'd want to sell before its warranty expired - the second or third owner, though, might later have reservations buying another one."

"The Audi A4 turbocharger particularly was a huge sticking point - they were failing within the warranty period even when Joe Citizen was driving. It didn't matter if you kept to the specified oil change intervals. Oil change intervals on those, I think, were around 10,000 kilometres - a lot of manufacturers try to keep ownership costs down - but a turbocharger generates a lot of heat in the oil and that causes rapid oil deterioration. It needs to be changed more frequently."

"I do probably half a dozen turbo builds per year for 1995-ish Audis, while turbos from a Subaru of the same vintage we're only now starting to see - and they've invariably had a harder life. To Audi's credit, though, they did upsize the A4 turbocharger in about 1999 - and it's a bolt-in replacement for earlier model. That did alleviate a lot of heat - being larger - and enhanced reliability."

What is your ultimate turbocar?

"I've got a spot for the 2JZ-GTE Supra - 6-speed, big brakes, some light turbo mods and they're a magnificent driver's car. Sure everybody's got one at the moment, but they've got a fantastic, quiet, understated motor."

"I prefer the 2JZ engine over the Nissan GT-R engine - they've got a lot more refinement and engineering and I think, overall, they're up a peg. Nissan are good at retaining an old design, revamping and reworking it and 30 years later saying, hang on - we'd better build a new motor... They also tend to get a bit coarse because the engine doesn't resemble its original configuration. You see a lot of vibration problems with Nissan - bits and pieces resonating, vibrating off, turbos coming loose and things like that. None of that happens with Toyotas."

What sort of changes have we seen in recent turbocharger technology?

"At the moment there's some incredible stuff out there, but it hasn't landed in Oz. I think a lot comes back to development of the turbos on diesel engines - I'd say the greatest amount of development in turbochargers has come from these small frame diesel turbochargers."

"The latest things out of Volkswagen and Peugeot are magnificent - I mean the management system has a lot more feedback in terms of turbocharger shaft speed and variable nozzle turbines are a great way to control that shaft speed. Unfortunately, though, it takes a while for technology to come out of development in passenger vehicles into a performance driven aftermarket application."

Have ball-bearing centre and ceramic turbine wheels made a tremendous difference?

"Yes and no. There are these guys called accountants and if they can build something 5 cents cheaper - when you take into account the number of vehicles being built - it's a cost saving exercise worth pursuing. A lot of the experimentation isn't only aimed at improving efficiency and reliability, but cost as well. When you look at a plastic compressor wheel, which is marginally lighter than an alloy wheel, it is also far cheaper to manufacture. The flaws, though, are that the blades tend to flex at high speed and then fracture. They're designed to do a specific job - they're as cheap and light as possible. Skylines - R33s and R34s - use plastic compressor wheels."

"The idea of ceramic turbine wheels, again, is fantastic but the reliability is not there depending what you want to do with it. The idea of having something that's an insulator connected to the main shaft - which is transferring heat through to the oil - is fantastic. In terms of reliability, though, the ability to bond something ceramic to something steel isn't quite there yet."

"When it comes to ball-bearing centres, some manufacturers will make them as small as they can. Ball bearings are an expensive thing to manufacture - far dearer than the older full floating bush. If the ball bearing selected is borderline at controlling the speed of the shaft under normal circumstances you can bet its life will be limited. If it's over engineered - with a bearing that's doing the job easily - its durability is far improved over the standard bearing set-up. Certainly, a performance turbocharger with dedicated performance roller bearings is significantly stronger than a bush-style turbo."

What are some common turbocharger failures on factory turbocars?

"It all comes back to maintenance - oil is the lifeblood of the turbocharger. If you don't look after the oil you might as well be putting money aside for a new turbo unit."

"Because the turbo is running at 700/800/900 degrees Celsius, you can't run oil under those conditions for any period of time and expect it to survive - it carbonises, breaks down, scores and, generally, destroys turbos. I find it's the manufacturers that are trying to extend the life of moderately good oils that are suffering in terms of turbo durability - and, again, that's a lot of the European vehicles. We see a lot more lubrication problems from those."

"Some of the problem vehicles we're now seeing are second-hand Japanese imports. Many have low kilometres, but they've perhaps never had an oil change in their life - that just destroys what are otherwise perfectly sound motor vehicles. I'd say over 50 percent of the vehicles that come in here suffer from a lack of servicing in Japan. When you're talking fine tolerances and fine orifices through blocks and cylinder heads it's easy for the oil to sludge and cause a blockage. Failure is not far down the track."

What causes turbocharger shaft breakage?

"A number of reasons - lubrication is always a good starting point because it's carrying heat away from the vital parts and, of course, if you get something too hot it'll break. Shafts will also break purely through their mechanical strength being exceeded - it comes back to the accountant building the turbocharger as light as they can to do the job. Breakage can also occur due to a sudden stoppage of the rotating assembly, such as when the turbine has swallowed something. So there are a good number of things, but lubrication is usually at the top of the list."

Can a crude boost control system cause shaft breakage through over-speeding?

"In extremities it can - it's important that putting on a bleed, or whatever, isn't the only thing you do without making some checks. That applies whether the car is worth $1000 or $100,000. Every action has an equal and opposite reaction - you've got to check the whole sequence of events. You might have just flicked the switch on a time bomb."

What sort of boost pressure is common on factory turbocars?

"Well, if you go back to the early-to-mid 1980s 6 psi was common - you know, non-intercooled, just getting into unleaded fuel and with fairly simple management. With premium-unleaded fuel available they've now got higher compression and often running 14 psi boost from factory. A lot of Saabs, for example, run 10 psi, Subaru WRXs are 11 - 12 psi and STis go up to about 15 psi. A Ford Transit turbo diesel we've got here at the moment makes 14 psi - diesels exceed 14 psi quite regularly."

In Part Two of our interview with Bill Keen we'll get the answers to some more nitty-gritty tech questions...

Contact:

Adelaide Turbo Service
+61 8 8377 2511

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