Auto-Matt

Mazda6 2007 Sports Sedan

2008-03-08T01:26:00.003+11:00

Background
Released in 2002 the Mazda6 was an immediate hit, as well as quite a curiosity. For a start, here was a Mazda that didn't look boring, and harked back to the days of the stylish early Astina's and RX-7's. Secondly the rather strange name that was an amalgam of Manufacturer and model. While officially the model name is Mazda6, it soon became known as the '6' and was soon joined by the Mazda3 and Mazda2.
The final surprise was the performance and handling. Nobody was more surprised it seems than Richard Hammond of Top Gear who reviewed the Mazda6 shortly after release in the UK.
Over the ensuing 5 years, Mazda proceeded to win many and various quality and reliability awards around the globe, was regularly acknowledged as being "best in class" and as recently as December 2007 won the Carsales Peoples Choice award in the medium sized category for the 5th time. Prior to that the Mazda6 was winner of the 2005 Wheels active safety program, in 2004 was rated as the best medium car by Drive (The Age) in their Top Ten Cars feature, and in 2003 was rated Best Mid-size Car over $25,000 in Australias Best Cars.
Significant then that even at the end of the product cycle, with a new model waiting in the wings, the Mazda6 is still leading the field.
Key to the Mazda6 story of success was the excellent 2.3 litre MZR four cylinder engine, which produced a still impressive 122kW and 208Nm of torque. Back in 2002 that output was in the realm of the 2.5 litre Liberty and JSII Vectra V6. The second key element to success was how the car looked. Both Ford and Mitsubishi can attest that building an ugly car is no way to sales success. The AU (awfully ugly?) Falcon almost sunk Ford, who were fortunately redeemed by the very impressive and attractive BA. Mitsubishi however started off on the wrong foot with the last (and hideous) Boulay Magna, and took barely a step forward with the US Galant based "380". Impressive dynamics could not make up for boring, and to some eyes ugly, styling.
The Mazda6 however was a stylish and attractive trend setter. Known as the Atenza in Japan, it was the first of a series of stylish Mazda's and aped the more extreme looking RX8 with sweeping cut lines across the bonnet and subtly flared guards. The optional "aero" body kit further improved the aggressive look.
The only omission some in the Australian market longed for was the V6 engine available in the USA, however this would have meant sourcing complete cars from the USA. The exchange rate made this unattractive, and more importantly the abysmal quality of the US models made the deal a no go. Maybe abysmal is a strong word, however the USA is the only country in the world where the Mazda6 ranked near the bottom of quality rankings, rather than the top. The Australian Mazda6 was sourced from Japan, and as such enjoyed excellent Toyota like levels of quality and reliability, without having to suffer the Toyota like boredom and lack lustre performance.
Review
It was a sad day when I took my MY02 WRX to the Mazda dealership and drove away in a brand new Mazda6 Sports Sedan. The WRX was great fun, however after more than 8 months and 18,000km of ownership, the lack of compromise and completeness of the Mazda6 has made a lasting impression. While it's lacking power to the tune of 38kW in comparison to the Impreza, it weighs the same and changes direction just as well, if not better. The Impreza is quicker through corners by virtue of it's all wheel drive grip, however the Mazda is agile and great fun to drive. During U-turns and tight corners it will easily light up the inside wheel, which leads me onto the surprising lack of traction control. Available in higher spec models it was not even an option on the Sports Sedan, which was a little disappointing. It is greatly missed on wet days, especially considering the generous torque produced by the 2.3 litre MZR, and the extremely short gearing in 1st gear. This leads me onto the next surprise. The gearbox ratios. Considering Mazda had 6 ratios to use, they all seem to be stacked quite close together, with 6th gear turning around 3000rpm at highway speeds. This is similar to 5th gear in the WRX, but a long way from the relaxed 2100rpm the Vectra spins as it lopes along sipping fuel. On a spirited drive through the hills I can see the rationale for 6 close ratios, however I think I'd on balance prefer 5 close ratios and a much taller 6th for cruising.
These minor quibbles aside, the Mazda6 is a great car, and surprisingly capable in many areas. The power output of 122kW might seem low in comparison to a Commodore or Falcon, however considering the weight of the Mazda6 is considerably less, it actually had a similar power to weight ratio to the 2002 VX Commodore and wasn't far off the mighty then-just-released 182kW BA Falcon, which was some 450kg heavier. The contemporary 4-cyl Camry was totally outclassed and some would say still is.
The MZR engine revs sweetly and cleanly to redline, and sounds great doing so thanks to Mazdas attention to the induction note, and pulls cleanly from rev ranges that would see the WRX requiring a downshift or a very long wait.
The boot of the Mazda6 is actually larger than both the Falcon and Commodore, which makes the "family car" case very strong indeed unless you need to regularly tow a large boat or caravan.

Treating drivers like adults

2006-11-20T10:03:00.000+11:00

Spiegel Online recently published an article called

CONTROLLED CHAOS:European Cities Do Away with Traffic Signs

From the article:

European traffic planners are dreaming of streets free of rules and directives. They want drivers and pedestrians to interact in a free and humane way, as brethren -- by means of friendly gestures, nods of the head and eye contact, without the harassment of prohibitions, restrictions and warning signs.

Now when I first started to read the article, my first thought was of the death and carnage that would result as cars ploughed headlong through crowds of pedestrians, unchecked by any barriers or warning signs.

How could this work? Drivers and pedestrians need to be told where they can and cannot go. They need to be told what is and is not dangerous. How would people know when to stop, when to give way, and when it was safe to proceed?

But do they? In my experience, most drivers by definition are adults. But what happens when you treat adults like children, by regulating every little thing they do?

Once again, from the article:

Psychologists have long revealed the senselessness of such exaggerated regulation. About 70 percent of traffic signs are ignored by drivers. What's more, the glut of prohibitions is tantamount to treating the driver like a child and it also foments resentment. He may stop in front of the crosswalk, but that only makes him feel justified in preventing pedestrians from crossing the street on every other occasion. Every traffic light baits him with the promise of making it over the crossing while the light is still yellow.

So the more we try to legislate for common sense, the more we drive it away. It's something we see with children, with employees and indeed with drivers. If you treat them like children and don't give them any responsibility, they will act like irresponsible children.

"The many rules strip us of the most important thing: the ability to be considerate. We're losing our capacity for socially responsible behavior," says Dutch traffic guru Hans Monderman, one of the project's co-founders. "The greater the number of prescriptions, the more people's sense of personal responsibility dwindles."

By introducing more and more rules, we're encouraging people to think less. We training them to simply obey the coloured light, the arrow or the number on the sign, rather than being aware of their environment and thinking of the consequences of their actions.

I only see two barriers to introducing this in Australia. One is minor and one is major.
a) the current culture of treating drivers like morons has created a generation of morons. Over time this will slowly change, and since the majority of drivers are sensible adults, this should not present a huge problem.
b) Removing all these controls also removes the various fines for disobeying them, and hence a huge revenue stream for the government. This presents a major problem, and thus I predict that it won't happen, but the reasons given will be because of "safety concerns".

Subaru Impreza WRX MY02 sedan

2006-10-15T22:48:00.002+10:00

A Quick WRX History Lesson
The WRX (or Rex as it is affectionately know) has well and truly become a cult-classic. The original formula of stuffing a powerful turbo-charged engine and drivetrain from a larger car into a smaller body was popular in the early to mid 90's and driven by the desire to be competetive on the world rally stage. Both Subaru and Mitsubishi took the drivetrains from the larger Liberty/Legacy and Galant respectively, and shoe-horned them into cars one size smaller. The resulting Subaru Impreza WRX and Mitsubishi Lancer GSR were lighter, faster, more nimble, and more importantly for the man in the street... cheaper!

Toyota eventually followed suit in 1997 and produced a WRC Corolla, however never produced a road-going version of the same car. Maybe they didn't need to. Subaru however focused almost all their marketing around rallying, and the success of the Impreza WRX and Subaru in general was evidence that they had made the correct decision.

When first released 1994, the Impreza was available with a 2.0 litre turbocharged boxer engine and all-wheel drive running gear. Now more that 10 years later, the fundamentals have not really changed. In Australia, only the MY06 Impreza WRX and STi received a change in the engine department, upping capacity to 2.5 litres. Prior to the MY06, the biggest change to the Impreza was the release of the MY01 "bugeye" model, which had a new chassis and body.

The Bugeye
The MY02 is the model I'm looking at today. The main reason for this choice is that I own one!. Hopefully I'll be able to offer a nice balanced view, but I'll state right now that I love all wheel drive. It adds a huge amount of ability to any performance car package.

The MY01 and MY02 are fairly unique in the Impreza lineup, in that Subaru decided to jump in with some sheetmetal and engine changes sooner than is usual. This was due to the rather polarising effect the styling of the car had when released. In fact, it copped quite a hiding in both the media and around the traps. I myself remember stating that I'd never buy one! The fact that the bugeyes were also heavier, and thus slightly slower than the previous classic shaped WRX only added to the negative press.

This to be fair tended to mask the fact that the bugeye WRX was greatly improved over the previous model. Torsional stiffness was up by 185% and longitudinal stiffness up by 250%, and the track on the sedan was increased by 20mm, which made for much better, more precise handling. Wheels were now 17" and there were a few extra features such as cruise control. It had much improved crash performance and NVH levels were much lower. There were also minor changes to the engine, such as a larger turbine wheel, larger repositioned intercooler and larger wastegate port. While these changes didn't improve peak power, they improved the power curve elsewhere by bumping up torque throughout the range, make for a more driveable car.

The rather negative reception of the original MY01 bugeye resulted in a few changes to the MY02. The most significant was the use of a 4.444 diff ratio to gain back some of the performance lost in the weight increase. Contrary to popular belief, this had virtually zero effect on the standing acceleration time to 100km/h because Subaru also changed the MY02 1st and 2nd gear ratios bringing them back in line with the MY01. The change in the diff therefore gave 3rd, 4th and 5th gears more punch, dropping rolling acceleration and overtaking times in these gears, chopping the 50-120km/h time by more than 1 second.

The rear diff on the MY02 was also changed to a Suretrac unit, as found on the STi, which Subaru engineers claim will deliver power to the wheel with grip even if the other wheel is not touching the ground.

So What's It Like To Drive?
What does all this mean in the real world?

The bugeye is fast. Here's where I tend to disagree with many motoring writers and others with a fixation on 0-100km/h times. The MY02 is slightly handicapped by its gearing in this regard, and requires a 2-3 change just before you hit 100km/h, thus adding up to 0.5 seconds to its time. In the real world covering distance is more important that reaching a velocity, because in a side-by-side comparison, the time to distance will be a direct indicator of who will be ahead at any point. This is where all-wheel drive shows it's hand, able to get off the line with the minimum of fuss.

No the MY02 is probably not quite as fast as the earlier, lighter WRX models, or the later more powerful ones, but anything else without all-wheel drive should be worried. As with most all-wheel drive cars, the punch off the line is fantastic, and over the first 100m it more than makes up for the weight penalty. For example the MY02 WRX will cover 100m in around 5.8 seconds, whereas the Holden 5.7 litre SV8 will take 6.2 seconds. You need an LS2 Clubsport to be able to cover 100m in 5.8 seconds, and for all of that time it's behind the MY02... gaining fast near the end. In the wet there is no contest whatsoever. The WRX leaves RWD rivals wheelspinning far behind. On public roads beyond that 100m you'll most likely start travelling at illegal and expensive speeds, and so it all becomes rather academic.

When I first drove a turbo Subaru (a Liberty RS turbo) it was a bit disappointed until I worked out the engine characterics. Down low a turbo Subaru can feel just like a little shopping trolley. But once the revs build, the acceleration comes on with a rush. To many people this is what they love about the RS turbo and WRX. The MY02 isn't as bad (or good depending on your perspective) as the Liberty RS, however you can get caught in the wrong gear, and you need to remember that at least 3000rpm is needed for decent acceleration. To achieve the best standing acceleration times as published in magazines, you need to build fairly high rpm (at least 4500rpm or more) and to be fairly brutal with the clutch. If you take a leisurely approach to getting moving, then if that V8 beside you tries to get in front, you probably won't catch him.

Where you will catch him is when the road starts to bend. The WRX handles well, being stiffly sprung with low profile tyres, but is not outstanding. What is outstanding is that you can get on the power almost anywhere, so the punch out of corners, and hence overall point-to-point speed, is so good. It's also relatively small and therefore nimble. The stock WRX tends towards understeer when pushed, however my car has an anti-lift kit fitted, along with a good alignment and Goodyear F1 GS-D3 tyres, which have gone a long way toward curing understeer at sane speeds. The anti-lift kit, despite common belief, actually increases fore and aft pitching slightly by reducing the "anti-lift" characteristics of the suspension. This effectively softer suspension gives greater front end grip. It also gives slightly more caster and camber. All this reduces understeer and increases corner speed. In fact the turn in can be sharp enough to cause the rear to step out in some cases, and getting on the power too soon if grip levels are low can result in power oversteer. This is obviously predominant if tyres are worn or roads are slippery, and caution needs to be excercised. The extra grip of the all-wheel drive system means that you're probably going to be travelling much faster when things let go!

Despite its rally heritage, the WRX is more geared to tarmac than dirt. Smooth dirt roads can be despatched quite comfortably, however once the road gets a bit rough or corrugated, the firm suspension and low profile tyres conspire to rob you of grip, and the WRX will skip and crash across rough patches while the ABS buzzes beneath your brake pedal. Braking distances increase and cornering grip drops away, although that phenomenal grip under acceleration is still available if you're brave or foolhardy enough to use it. Oversteer rears its head again under these circumstances.

In the practicality stakes the Impreza loses out a bit. There's no hiding the fact that it's a small car. Our other car, a 99 Holden Vectra, weighs about the same, has similar crashworthiness, but feels bigger in every respect. More interior space, and a much bigger boot. While the Impreza does at least have four doors, it's only a family car for a small family.

Cruising interstate in the WRX is reasonably economical for a car of this performance level. We generally obtain around 8 litres per 100km cruising on the highway, although the gearing in 5th means that at 110km/h the engine is spinning at 3300rpm. Not ideal for economy or NVH levels, but does mean that changing down a gear to overtake or climb a hill is uneccessary in all but the most extreme situations.

Overall though, the WRX is easy to live with once you learn its foibles, and is a ball of fun to punt along winding stretches of tarmac. In wet weather the performance is almost the same as dry, and many is the frustrated V8 owner who's had to put up with a WRX "playing with him" in the rain. It won't cost you a fortune in fuel unless you're very liberal with its performance, and 17" tyres these days are very common. Resale is quite good (which is bad if you're buying), and currently you can pick up an MY02 from a dealer for between $25k and $30k. Private sales are generally cheaper, but caveat emptor! (buyer beware). While Subaru's are generaly fairly solid and reliable, a vehicle inspection is always worthwhile as the WRX tends to be harder driven then most.

My final judgement is to give the MY02 WRX
4/5 STARS - * * * *

Some of my movies: Rally and Historic

2006-03-09T12:16:00.000+11:00

I thought I'd have a play with Google Video uploads, so I've placed two of my recent movie making efforts online.

The ARC Rally of Melbourne 2005

Historic Winton 2004

Enjoy!

Rex Pics

2006-03-07T20:41:00.000+11:00

Subaru Impreza WRX MY02 Sedan

What does an ALK do?

2006-03-07T14:42:00.000+11:00

ALK stands for Anti-Lift Kit and is a common aftermarket suspension modification. It's basically a new set of lower suspension mounts that adjust the front geometry and alter the anti-lift character of the suspension. Cost of a kit for my 2002 Impreza WRX is around a few hundred bucks. If you're serious about track work and altering the front suspension you'd be better to go straight for a full kit with new strut tops. For the odd weekend squirt the ALK is ideal. Cheap and effective.

A common misconception is that the kit will REDUCE front end lift on acceleration. This idea comes obviously from the name anti-lift, however the revese is in fact true.

Normal suspension in any car has a characteristic known as anti-lift, which defines how much forward or backward force is transferred into upward and downward force when braking or accelerating. This force results in pitching and diving. A suspension setup with a 100% anti-lift will not pitch or dive at all, but instead transfer all forward and backware force to the tyres. This is bad however, because the tyres have to do much more work and you will much sooner overcome the level of grip they provide. The tyres will also spend less time in contact with the road if the surface is anything but billiard table smooth.

A car with less anti-lift (or more tendency to lift) will pitch and dive more, however the level of grip is higher because the fore-aft load on the tyres is reduced and they spend more time on the road. This is the reason why cars have springs and shocks. Less suspension movement and firmer suspension is good in terms of responsive handling and quickly changing direction, but bad in terms of outright grip, so some sort of happy compromise is required. That's why any car, even F1 cars, have some form of suspension to allow vertical movement, and do not simply bolt the wheels direct to the chassis.

The WRX ALK does two things.
1) reduce the anti-lift characteristic of the suspension, which in turn increases the level of front end grip for the reasons outlined above.
2) increases the amount of caster which in turn gives more dynamic camber when cornering.

In concert with the kit, a slightly different set of wheel alignment parameters can be used, and are generally provided by the manufacturer of the kit.

On the road, the difference is quite noticable. The WRX turns into corners much more eagerly, and higher cornering speeds can be attained. The natural tendency to understeer is reduced and power can be applied to better effect. Overall I'd recommend this modification to anyone.
For the dollars it's a very effective modification.

A WRX, a Monaro and a Mountain pass

2006-03-05T22:00:00.000+11:00

I had the pleasure yesterday of driving the spectacular strip of bitumen that winds from Marysville past Lake Mountain over the range to Reefton and Warburton. The route we took can be viewed on Travelmate.com.au, which has an excellent Map Maker feature for creating maps and routes.
Marysville to Reefton Map

What made it even more fun was that one of my mates was tagging along in his dark purple Holden Monaro CV8. Known in the USA as the Pontiac GTO, and in the UK as the Vauxhall Monaro, this 2004 build example is the last of the original classic shapes before they got the Septic styled bonnet vents. All in all it's a nice looking car with a purposeful stance. It sports the Chevrolet sourced Gen III 5.7 litre V8, pumping out 245kW and 465Nm, giving it an 85kW edge over my 2002 build WRX, but also hauls an extra 300kg.

Even so, every one of my 160 kilowatts was lugging an extra 2kg on average, so the Monaro definitely had a lot of straight line squirt. In my favour, the CV8 was a 4 speed auto... (oh and a big heavy lump). We were both running Goodyear F1 GS-D3 tyres, though mine were 17" and his 18".

It was a brilliant day for an attack on a mountain pass, with not a cloud in the sky and temperature up around 30 degrees. To be honest, it was actually a bit hotter than ideal for the WRX, with the turbocharged engine preferring cooler denser air, the better to cram into the cylinders, but as it turned out that was nothing to worry about.

Winding up out of Marysville we were stuck behind a little Corolla for a few minutes, so I had a big purple Gen III looming in the mirror like a big playful doberman. Once the Corolla courteously pulled over and let us passed, we picked up the pace a little, but the straights and flowing curves meant that we were both pegged at the 100km/h speed limit.

Finally that sign that we all know and love appeared. The little squiggle with 35km/h recommended speed.

Left hander first... Here we go...

Late braking, blip the throttle into 2nd, point it in, nail it just before the apex and around you go. The corner tightens up but you can just wind on more lock and tuck the nose in... still accelerating. Exiting the corner, changing into third and straight into a right hander... short straight, on the brakes again, another left, another right.

The CV8 is nowhere... absolutlely nowhere to be seen. Within about 90 seconds I've put about a kilometer between the two of us. I back off and once the road opens out into short straights and sweepers, the big V8 comes looming in the mirror again. The top end of the Gen III is fabulous when it can be put to good use.

Then once again the road tightens up, snaking left and right with added savagery. The bitumen is smooth, sticky and limits of adhesion are very high. The WRX is in its element again, changing direction eagerly, transferring all 160kW to the road with the wonderful surge you get with a turbo Subaru and hurtling through the forest like a tiny white rollercoaster. I back off again and in short order I see the Monaro exiting the corner behind me nice and flat, but with a little twitch as the tail tries to step out. Off we go again.

Once or twice I enter a corner a touch too fast, but a slight lift of the foot rotates the tail out and nose in to put it back on line. Sometimes if you hurl it into the corner too eagerly, the tail comes out a touch before settling and hurtling onward again. It's a very easy, forgiving car to drive fast and it's easy to see why the WRX was a target for theives and ram-raiders. The sting in the tail is that if you do reach it's limits, you're going very, very fast!!

A passenger who rode in both cars commented that the Monaro was much more comfortable to ride in, but you could also feel the rear end twitching on corner exits as it tried to put down all 245kW through the 18" tyres.

All in all we had a great day enjoying two nice performance cars in an environment that they were meant for.

Fantasy Land?

2006-02-10T12:01:00.000+11:00

Just for a moment I'd like you to imagine that you are living in a magical fantasy land. In this land there lives a man called Mr Mint who owns a number of widget factories. The factories are full of machines churning out widgets.

Unfortunately, the widget machines occasionally fail, and because they are running at speeds of up to 10,000rpm they tend to cause serious damage, and sometimes injury and death when this happens. This is a serious problem for Mr Mint because not only is it costing him money, but it is endangering the lives of his people.

One day Mr Mint comes up with an idea.
"I know!" he exclaims. "I'll run the machines at a slower speed. Then when they fail the damage will not be as severe!"
"Hang on Guv," exclaim the machine operators. "Why don't we look at why the machines are failing and try to stop it happening so often?? Maybe we need more training!! Maybe some of the machines are too old!! Maybe the materials being used are not suitable"
"No." says Mr Mint, shaking his head. "The speed is the problem. We'll run things slower and that will reduce the problem."

Unfortunately for Mr Mint the machines continue to fail, explode and generally wreak carnage with monotonous regularity. The machine operators are also having a harder time because now, rather than just monitoring the overall widget-making process and running the machines accordingly, they now have to keep an eye on the needle on the speed dial.

The continuing machine failures worry Mr Mint. "It must be those operators." he decides. "They must be running their machines too fast! I'll need to set some limits and penalties."

Mr Mint implemented fines for operators who were running there machines faster than the recommended limits, however there was still little change to the number of injuries, fatalities and the amount of damage created by exploding widget machines. He put in place random checks and cameras to ensure that the speed of the machines remained within the recommended limits, but still the carnage continued. The only consolation was the increasing amount of revenue from the fines,

Sadly for Mr Mint he was eventually fired for incompetence, but only after hundreds of operators had died each year and thousands were injured, not to mention the material costs involved.

But don't worry... this is all just a fantasy land... it could never happen in real life... could it?

More 3/16 boost control mod testing

2005-12-17T20:14:00.000+11:00

Well after my last post and some discussion with various people, I decided it was worth doing a simple test to prove or disprove my theories about the 3/16 boost control mod.

My understanding about the boost control system as it applies to my MY02 Subaru Impreza WRX is as summarized as follows.
- The wastegate takes its pressure feed from the intake manifold (post compressor).
- The wastegate valve is set to around 7 psi.
- All other things excluded this gives a maximum boost pressure of 7psi.
- The pressure feed line contains a T-piece that feeds the boost control solenoid.
- This solenoid allows the ECU to bleed some pressure prior to the wastegate, thus giving more boost pressure overall.
- Inline with the solenoid is a restrictor.
- The restrictor is used so that the system is not sensitive to the internal diameters of all the piping and connectors, but rather to a single minimum point.
- This restrictor tends to govern the effect of the solenoid.

What the 3/16 mod is supposed to do (if you can believe what you read on the internet) is to enlarge the restrictor, and thus allow the solenoid to take effect quicker, and possibly also give a higher boost level from the Mitsubishi TD04 turbocharger.

If you know anything about control theory (and why would you! It can be amazingly boring stuff) you'd know that any system with a feedback loop can by pretty sensitive to changes. If you alter a part of the system you risk creating a situation where it's chasing its tail. In this case, if the boost rose too quickly, the ECU would peg it back, which would happen too fast, then it would open it up again. The result would be jerky and inconsistent power delivery, which has in fact been reported by others experimenting with this mod.

How to test my theory?

I figured the safest way to test things was to block the line to the boost control solenoid. If my theory was correct, this would cap boost at around 7psi and effectively give the WRX about ~120kW instead of the full whack 160kW. Why 120kW you may ask? Well 7psi is about 0.5 atmospheres (or 0.5 bar) which means that the engine will be getting 50% more air/fuel mixture than under natural breathing, which in broad terms should relate to 50% more power than a comparable naturally aspirated motor. This means that at 7psi the WRX is effectively running a 3.0 litre engine, and at full noise running around 14psi its effectively running a 4.0 litre, which is born out when you compare output figures of various cars.

Armed with all this knowledge and no small amount of consternation I pulled the restrictor from the hose, wrapped it with plastic and plugged it back in, thus blocking the hose completely.

Driving the car was quite interesting.

The characteristic WRX power delivery was altered quite a lot. The power came on smoothly up until around 3000rpm just like before, then... it just kept coming on smoothly. Instead of that grin-making whoosh that usually arrives, it just kept pulling strongly. It certainly felt stronger than a naturally aspirated 2.0 litre, and closer to a 6 cylinder in feel, but nothing like the usual WRX rush.

The turbocharger was definitely still working, because since I have the intake resonator removed I could still hear the spool up, and the factory BOV sneezing occasionally. However my theories seemed to be proved correct. The Mitsubishi TD04 turbocharger seemed to be making about 7psi with the hose blocked, and around 14psi (or whatever stock levels are anyway) with the restrictor in place. If the line was unplugged completely I'm guessing that the turbocharger would generate as much boost as it could, which is a pretty cheap way of upping your power, as long as you don't mind most likely detonating your engine.

My next tests will be to try some different restrictor sizes, or fit an adjustable valve. Stay tuned for more.

The (in)famous 3/16 boost control mod

2005-12-06T20:16:00.000+11:00

Many a WRX enthusiast will have heard of the 3/16 mod. It's said to be a very cheap way of upping the performance of your stock, garden variety Subaru Impreza WRX. Unfortunately there's not much in the way of scientifically valid testing done on this modification, and opinions vary widely.

After a fair bit of research I decided to try the mod on my stock-as-a-rock MY02 Impreza WRX, and have been quite pleased with the results. However I will make the following disclaimer.... Fiddling with the boost control system on any turbocharged car is potentially dangerous. Overboost can destroy your engine in extreme circumstances. Make any changes AT YOUR OWN RISK.

What this mod does is give the stock WRX boost system a little kick. As I understand it, it allows the boost control solenoid to act faster and have more effect, which means that the boost comes on earlier and slightly stronger. It also means that if you overdo things, you'll end up with spiking, overboosting and underboosting, as the system chases its tail.

From what I've read about the WRX boost control system, it works like this... The wastegate is mechanically set at around 7psi. This is how much boost a car would run if the boost control solenoid was always shut.

The solenoid basically allows a small amount of air to bypass the wastegate, thus the turbo has to build up more pressure to have the same effect. The ECU thus controls the boost by opening and closing this solenoid. Solenoid open for longer means more air bypassed and more boost.

To avoid having to worry about the diameter of all the tubing in the solenoid circuit a restrictor is placed which gives you a set flow rate. Since this is the narrowest item in the circuit the restrictor is the deciding factor in how much air is bypassed through the solenoid.

Increasing the restrictor diameter means that opening the solenoid has more effect... or in other words the boost builds faster and potentially to a slightly higher level.

If the diameter is too big though, the boost will climb and fall quicker than the ECU can cope with, and it will overcorrect. The pressure will in that case be inconsistent and power delivery not smooth. You may get boost spiking to high levels and then cutting out as the WRX computer tries to compensate.

The replacement restrictor I sourced from my local hardware shop. It's original application was a hose coupler for a automated garden watering system. I then drilled it out to the required size and replaced the factory item.

Now I don't have a G-tech or boost gauge (although others with this mod have noticed boost arriving quicker and slightly higher).

Seat-of-the-pants-wise I found that on a hill that I'd previously have to down change to 3rd gear, I could now climb in 4th. I also found the traditional WRX Whoosh! arriving about 500rpm earlier.

All in all I've been pretty happy with the results, and have been driving the car with this modification for over a year now with no noticable down side.

Holden JS Vectra CD sedan

2005-11-16T23:31:00.000+11:00

Background
The Holden Vectra has a heritage that many at Holden would rather forget. In Australia the J-series cars began with the infamous Camira. And while it managed to win the Wheels magazine "Car of the Year" for it's performance and roadholding, its quality left a little to be desired. The bits that fell off regularly tended to detract from its willing engine and high speed handling. Holden persisted with the Camira for many years, and just when they seemed to get it all right with the JE, which sported a 2.0 litre MPFI 85kW motor, they axed it and instead started selling rebadged Camrys as the Holden Apollo and expecting the car-buying public not to notice. At least the Camry was reliable but that was about the nicest thing you could say about it. The price of the Yen at least meant that it made economic sense.

Then in 1996 rumours of a new mid-size Holden began to leak out. It was the latest J-body car from General Motors in Europe, and the changing world economy made Euro imports a proposition once more. For Holden to re-use the name Camira would most likely result in sales suicide, and for a while the revival of the Torana nameplate was speculated. However Holden chose to use the same name as the European model, and in 1997 the JR Vectra arrived in Australia.
Holden had grand plans for the Vectra, and in late 1998 began locally assembling the JS Vectra at the Elisabeth plant in South Australia, planning to supply Australia and Sout East Asian markets, however changing Asian economic fortunes and the need to manufacture the Monaro meant that after only a few years of local manufacture, the Vectra returned to being fully imported.

This was a shame because the local car had some subtle but welcome tweaks over the imported model, the most significant being a boost in capacity in the 2.0 litre 4cyl to 2.2 litres, and revised suspension and gearing. The 2.0 litre was already putting out a class leading 100kW while offering excellent economy, and the 2.2 litre variant offered a welcome dose of low down torque, and an extra 4kW up top, without sacrificing much in the way of economy.

When the ZC Vectra arrived it really moved up an entire market segment into the medium size luxury class, leaving the niche vacant for the new Daewoo arm of General Motors to fill.

Vectra CD iD
This review of the 1999 JS Vectra CD can be considered a long term test... very long time. I've owned the Vectra since purchasing it new in February 1999 for the last six and a half years. In that time it's travelled over 120,000km. This was one of the Australian assembled cars with the 2.2 litre 4cyl and 5 speed manual transmission. Being the CD model it came loaded with all the good bits, such as Traction Control, Anti-lock brakes, dual airbags, Cruise Control, Trip computer, CD player, foglights and alloy wheels. The letters "iD" indicate that it has been fiddled with by a branch of HSV that provided various option to individualise the car. In my case the Vectra was fitted with an iD front and rear spoiler and sideskirts and alloy wheels. It even had an individual build number plate in the engine bay to make you feel special.

The iD body kit was actually supplied by the well known modifier of General Motors cars in Europe, Irmscher, located in Stuttgart.

Curiously enough I ended up purchasing the Vectra without ever driving one. Strange I know, however all the research I did and reviews I read seemed to point to it being a "good thing". In comparison to the other 4cyl cars in its class (the Mazda 626, Toyota Camry and Ford Mondeo) the Vectra had more power, better economy, more features, and outhandled all bar the Mondeo. It also looked by far the best to my eye. Another point in its favour was that in Europe the Vectra and Mondeo were pitched against the Audi A4 and Mercedes C-class, which made the prices in Australia a relative bargain. To buy a similar spec Vectra in the UK would cost up to 30% more that the Australian sticker price.

How does it Drive?
Once I was behind the wheel, the Vectra certainly didn't disappoint. The 2.2 generates plenty of torque from as low as 1000rpm, and so is virtually stall-proof. The torque delivery also makes for very relaxed driving around town, and minimises the need to change gears. The gearing is perfectly suited to the engines character, with fairly tall ratios that mean a leisurely 2000rpm or so at highway speeds. 2nd gear will take you all the way to 100km/h if you can sneak close enough to the limiter, and get you there in close enough to 9 seconds flat. If you have to grab 3rd before the 100 mark the time blows out to almost 10 seconds, as often published by less commited motoring journalists.

The standing 400m is despatched in around 17 seconds, which is a far cry for the sub 15 time of my WRX, however the Vectra makes up for standing starts with its in gear and rolling start performance. Plenty of torque mean in situations where the WRX is left waiting for revs and boost to build the Vectra leaps away with a chirp of the tyres. Traction control is very much appreciated in wet weather.

Handling wise the Vectra is quite neutral and surprisingly quick. Two track days at Winton Raceway mixing mostly with V8 Commodores revealed how well it carved up the corners, and caused a few to ask if it was stock. It was only left wanting in top end speed down the main straight. In comparison with the WRX the Vectra does not feel as fast due in part to it's less supportive seats and lower revving engine, however if you have time to look at the speedometer in tight corners, the Vectra carries the same corner speed as the Subaru. It loses out on corner exits however, as the front wheel scrabble for grip and understeer relentlessly towards the outside of the corner while the traction control madly tries to keep things in check. Lifting off however tucks the nose back in and can even step the tail out nicely. On B grade backroads where the surface is bumpy or broken, the Vectra's 15" wheels and 60 series tyres just soaks it up and it corners flat and confident where the WRX will feel nervous and a bit harsh.

What does it cost to run?
The Vectra is amazingly economical for a car of its size and performance. Partially this is due to the relaxed gearing, and partially I think is due to the overrun cutoff feature that is common in many modern cars, which shuts down the injectors completely when the car is coasting in gear and the engine is being driven through the gearbox by the road speed. You can see this occuring by watching the fuel consumption in the trip computer which drops to 0l/100km as you start to coast down a hill.

Cruising around town it is quite easy to obtain 8.5l/100km and travelling interstate a figure somewhere below 7l/100km is quite common. The best ever obtained was 6.1l/100km, which gives the Vectra a range of almost 1000km from it's 60 litre tank. That means it will be able to travel Melbourne to Sydney on a single tank. In fact a friend once travelled to Sydney in their Hyundai Excel and only managed 7l/100km while the Vectra did 6.5l/100km.

Does the family fit?
One thing the Vectra does very well is haul things around. The boot is bigger than a Commodore at 500 litres, and can swallow our Emmaljunga pram without any disassembly required. While 5 adults can be a bit squashy, there's tons of room for kids, and the interior is comfortable and well appointed. There are the regulation anchor points for carseat and child restraints, however you'll have to get your own hardware. The Subaru has clip on points built into the seat. The Subaru also gets locking seatbelts for securing baby seats, while the Vectra does not.

Buttons and bits
Where the Vectra wins points is for locating all the window controls on the centre console, allowing the front seat passenger to operate windows for back seat children, and having a cruise control that doesn't need to be turned ON and OFF. Why Subaru feel I should have to press two buttons to activate cruise, and make one of them hard to see beneath the steering wheel is beyond me. The Vectra also wins praise for having the foglights on a toggle switch that turns off with the ignition, thus avoiding the problem of leaving them on and suffering the wrath of the anti-fog-light evangelists. The central locking in the Vectra also locks and unlocks the fuel cap and boot, thus removing the need for an inconvenient remote release. You also have the option of deadlocking the doors, which means that cannot be opened even from the inside.

Any problems?
Since owning the Vectra there have been a few minor issues and one major one. When virtually new it exhibited a stalling problem which was known to Holden and resolved immediately with a new Idle Air Control valve. Then sometime within the first few years there was a problem with the wiring of the indicators which caused the flash rate to vary. Once again Holden resolved the problem immediately. Then about a month from the end of the warranty and ticking/tapping noise was noticed, and the car was taken to the dealer to investigate. They diagnosed the problem as a chipped crown wheel in the gearbox/diff assembly, and since they couldn't get a replacement part, they replaced the entire gearbox and diff under warranty. This took a week, so was a little inconvenient, but I was nevertheless happy to not be paying for a new gearbox.

How do you rate it?
I'll admit that I love driving the Vectra, and have been more than happy with it.
I can't see any other medium size sedan doing anything better for the money.
5/5 stars - * * * * *

What's the point?

2005-11-15T09:05:00.000+11:00

G'day all,
There are a lot of places you can read and see car reviews. Magazines, newspapers, television, and especially on the internet. So whats the point of producing more reviews? The short answer is that I love talking about cars! The long answer isn't much more complicated. I'm now 35 and have always loved driving, and have driven a lot of cars. I've done the odd track day, and I'm the type of guy who people ask for advice when buying a car. I've got a young family so need something practical, but also want something that's fun to drive. I don't think my perspective is unique which is why I think it might be useful. Currently I drive a Subaru Impreza WRX (MY02) and a Holden Vectra CD (MY99). They're both great cars for different reasons. Hopefully you'll find my opinions on these and other vehicles useful and amusing.
Matt