AS YOU stare at an invoice with lots of numbers and dollar signs on it you may find yourself asking ‘why’? As I was handing over a fair whack of my hard-earned recently, it occurred to me that there are probably much cheaper hobbies than farting around with old Land Rovers … pinning butterflies to bits of cardboard, for example.
The ‘why’ is most likely down to a childhood spent rattling around the family farm in my mum’s Suzuki LJ60, a bare-bones live-axle four-wheel drive that sounded like a thousand angry lawnmowers and had all the creature comforts of a sliced-open 44-gallon drum.
That bloody thing went everywhere, albeit trailing a stream of blue two-stroke smoke from an exhaust mounted on the front bumper. Mum shed more than a couple of tears when time and tin-worm saw it pass into other hands.
So now, I find myself embarking on the financially questionable journey of improving my Land Rover Defender 110 Perentie, code-named Project AWOL.
To date, I’ve been content to spin my own spanners getting the old girl into shape, but, for the sake of my neighbours (due to intermittent garage profanity), I elected to farm out the installation of a turbo kit and power steering to someone with much more expertise and patience than I seem to possess.
After dedicating valuable office time to scouring internet forums, I now know the correct colour code for a SWB Land Rover Series III Game. However, I was none the wiser on the best way to extract some usable, reliable grunt from the 3.9-litre Isuzu 4BD1 engine. So I had a chat with Brad at KLR Automotive in Sydney. These guys know Perenties inside and out and have put together a reliable yet rewarding turbo kit for the Isuzu donk.
In naturally aspirated form this engine is only good for about 66 lazy kilowatts. The addition of a non-intercooled, relatively low-boost turbo is said to effectively double that output. The turbo in question is a Garrett GT22, and it manages to produce boost pretty much just off idle, which comes in handy in those mucky situations we find ourselves in away from the blacktop.
I then got onto Landy specialists MR Automotive in Redcliffe to see if they could handle the heavy lifting on my behalf. I was already using these guys as my go-to for parts, but they have a loyal following among Landy aficionados for mechanical work as well. The kit arrived complete with a crossover pipe, headers, etc.
The old-school truckie in me couldn’t resist also getting an EGT gauge and tacho installed at the same time. The EGT ended up being an easier ask than the tacho, as the Perentie’s alternator lacks a W wire to transmit rpm to a tacho. I persisted!
Anyway, it also gave me an excuse to get a leak on the alternator-mounted vacuum pump fixed, which also turned out to be the reason why I was having issues getting the centre diff to lock. All this disruption to engine-bay plumbing required a new exhaust system, so a new 2.5-inch exhaust system was also installed.
And then we reach the point many car nuts reach: where to stop? And in the case of the Perentie, what is the weakest link with the gain in power? The answer to that question is, without a doubt, the clutch. The standard clutch is barely adequate at the best of times, so I opted to go for a heavy-duty clutch while I was at it.
After a long week of unbearable anticipation, the day finally arrived to pick up my revamped rig. It was a revelation. As the 4BD1 is essentially a truck engine it has a long, flat torque curve from about 1000rpm, but take the revs above 2200rpm and you’ve pretty much run out of torque. That’s why the Isuzu engine doesn’t really need a very big turbo or a gutful of boost.
If you’re wringing the revs out to 3000rpm to get boost you’re not getting the benefit of the windmill where you need it the most. Not only that, you’re also thrashing it.
With just 15psi of blow and the addition of Isuzu power steering, my camo-clad 110 is in serious danger of becoming almost zippy. It has transformed the Landy to a usable and fun off-road animal.
I just can’t stop smiling when I drive it. The turbo has even quietened the engine to the point where an actual conversation is possible at speed. Not only that, it also manages to elicit an off-idle whistle that is reminiscent of an old 14-litre BC3 Cummins truck engine… it doesn’t take much to make me smile.
4x4 History: 70 years of Land Rover
With all this new-found power and aural satisfaction, I’ve decided to head to Moreton Island for an extended weekend – the perfect environment to put my newly boosted Perentie to the test. That said, in the back of my mind I am wondering if this newly minted turbo powerplant will cause issues with the rest of the truck. Stay tuned, more money may be required… stuff may break.
4x4 Shed Log: 1988 Land Rover Perentie Defender 110
Current mileage: 104,140km
Date acquired: February 2017
Mileage this month: N/A
Average fuel consumption: N/A