Testing, testing… testing?
Cruiser 3.0D-4D gets the treatment in Lesotho
When Toyota 4x4 specialist N1 4x4 realised there was a gap in the market for Land Cruiser 4.2D owners who were looking to replace the tough but low-on-power 1HZ six-cylinder oil burner, they looked the way of the Hilux/Fortuner 3.0D-4D engine. In development for more than a year, we joined the team on one of their final research and development trips to Lesotho, for some high altitude tests.
WE’VE recently spent a lot of time in Lesotho. We even took our annual Adventure there (you can read about it elsewhere in this issue).
On that trip though, we selected a route to cater for Average Joe drivers with very limited 4×4 driving experience, driving stock standard vehicles. So no madcap Grade 5 obstacles were on the menu.
The team from N1 4×4 though, had completely the opposite in mind: they were looking for some of the most extreme high altitude tracks they could find. At least Grade 5 trails.
Before we get to our research and development trip though, some background on N1 4×4’s unique take on the Cruiser powertrain, using the familiar four-cylinder D4-D that also powers a gazillion Hilux
bakkies and Fortuner SUVs running around our roads.
Specialising in Toyota’s hardy Land Cruiser, the N1 4×4 team identified a need for a suitable engine replacement for high mileage Cruiser 4.2Ds. Although the naturally aspirated 4.2Ds are as tough as nails, their on-road performance is notoriously lacking in, well... just about every department.
Maintaining 120km/h on the open road is all but a pipedream for a 4.2D driver. Want to tow something heavy with a 4.2D over a long distance? Not a good plan.
Instead of swapping the legendary 1HZ 4.2-litre straightsix diesel engine with a similar heart, why not upgrade to something that rectifies some of the 1HZ engine’s obvious shortcomings? Like an engine that will ensure a cruising speed of 120km/h is a realistic option, up hill and down dale.
Enter Toyota’s well-proven 3.0D-4D four-cylinder engine. But it’s not quite as simple as extracting the 1HZ mill from a Cruiser’s engine bay and inserting the three-litre motor.
THE RIGHT FIT?
Besides the obvious custom parts such as engine mountings and adaptor plates, one of the biggest challenges in a conversion such as this is getting the electronics and electrical systems sorted.
The N1 4×4 team spent many months trying to source real McCoy wiring harness connector plugs, and finally managed to do a bulk purchase in Australia.
This was followed by months of experimenting with different turbocharger set-ups on the 3.0D4-D engine; the grey single cab you see on these pages was used as the official development unit. And things didn’t always go according to plan. N1 4×4’s Louis Weichelt explains.
“We were doing tests with different types and sizes of hybrid turbocharger, to find the ideal middle ground between power and reliability. The stock D4-D turbo doesn’t do more than 1.6 bar boost. If you push past that mark, reliability is compromised. One day we landed up on a stretch of road we often used for high-speed tests. I was going quite fast, when I heard a strange popping sound and the next moment, a big dent in the bonnet, along with a loss of power... it’s all part of the process.”
The ideal was to find a larger capacity turbocharger that wouldn’t be spinning near its
maximum capacity more often than not. And in time that turbocharger was found.
The engine management system is also a vital ingredient, and in this department, the team opted for the Aussie-made Motec system, a leading brand in motorsport.
“It’s a bit more expensive than other systems but you can literally adjust the engine parameters exactly how you want them, for every 100r/min,” says the company’s Cliff Weichelt.
The N1 4×4 off-road racing Land Cruiser uses a Motec system. As does every other top cross-country rally team in the country, including the Toyota Gazoo Racing SA factory team that competes in the Dakar Rally.
The standard 4.2D final drive ratio is 3.9:1 and is ideal for lugging heavy stuff over rough terrain but not so great when you drive at higher speeds, when the engine revs quite high. So the N1 4×4 team swapped the standard ratio for the V8 D-4D Cruiser’s 4.3:1 ratio. With a healthy increase in power, and the longer final drive, cruising at 120km/h would not only be a realistic option, but also a more comfortable, less noisy affair.
With the suitable hybrid turbocharger fitted and tested, a performance exhaust from De Graaff added and the engine management system tuned, the three-litre engine delivered about 170kW and around 500Nm of torque.
However, it had never been tested at high altitude. So a 1 600km round trip was planned to Lesotho… peaking at around 3 300m above sea level it doesn’t get higher than this in southern Africa.
THE DRIVE FROM GAUTENG TO LESOTHO
If there’s one thing you can’t accuse a Toyota Land Cruiser pickup of, it’s that it is a refined, comfortable beast. It was just after 5am, and we were driving the grey pick-up out of the city. The clutch is heavy. The steering is vague. The cabin is noisy, filled with diesel clatter.
But when you plant your right foot... golly! Sure, there is a bit of lag to work around, what with the taller gear ratios, but when that hybrid turbo starts boosting, oh boy! Your head is snapped back, the rear wheel with the least grip battles for traction, as the Cruiser blasts forwards like a bat out of hell. We hit the highway, and in fifth gear another trait becomes obvious: the 3.0D4-D Cruiser is comfortable at 120km/h. If you want to overtake, there’s no need to touch the gear lever either – a dab of right foot will see the Cruiser blast forward, picking up speed at a prodigious pace.
We reached Van Reenen’s Pass in good time.
We were running behind the second Cruiser, at around 80km/h. Unsighted roadworks in the fast lane of this notoriously dangerous pass suddenly filled the road, along with a string of slow-moving trucks in the left lane. The Cruiser in front of us jumped on the brakes, and we followed suit moments later... but we came oh-so-close to rearranging the tail of the white Cruiser with our LAS bull bar.
The Cruiser’s brakes have never been its most outstanding quality. N1 4×4 offers a Powerbrake upgrade for the
“It had never been tested at high altitude. So a 1 600km round trip was planned to Lesotho… peaking at around 3 300m above sea level it doesn’t get higher than this in southern Africa”
Cruiser, which we would most certainly recommend. It will add about R7 000 to your bill.
Later, after a few stops along the way, we reached the final stretch of dirt road before the South African border post. The plan was to head up Sani Pass. SURGING AHEAD
N1 4×4’s Motec expert – considered to be the best in the South African business – had loaded a temporary high altitude programme for the ascent to more than 3 000m.
But, as we were climbing higher, heading towards Lesotho, it became clear that the D-4D engine wasn’t entirely happy. All the power was there but the turbo lag became more pronounced. Both Cruisers also displayed a new ‘surging’ trait, as we made our way up the pass.
We made it to the Lesotho border post without incident, it was only when we restarted the engines after completing the formalities that there was an initial reluctance to idle. Once we revved it a bit, it was fine again.
We made it to Sani Mountain Lodge, for our first night in Lesotho. We were planning to tackle a tough 4×4 track leading to the Letseng Diamond Mine the next day. After the 4am start, we all tucked in early as we were expecting to be battling with some rocks and boulders all of the next day.
A CHANGE OF PLAN
After breakfast and after settling the bills, we loaded up our gear and... there was a problem.
Both Land Cruisers refused to start. Each engine would spin. Then, for the briefest of moments, it would seem as if it was firing to life. But then it would die again. Some phone calls back to South Africa traced the problem to the engine management system, clearly the default high altitude settings were not doing the trick.
We tried to ‘charge’ the glow plugs directly from the battery, to see if that would help. But it didn’t. Next we tried spraying some deodorant into the intake manifold but that also made no difference.
As a last resort, we hooked up the Cruisers behind the lodge’s Cruiser V6, and both were soon running again. Clearly the electronics and the high altitude were not on the same page though, which left us with a conundrum: do we push on to the desolate valley near Letseng mine? We were pretty sure the Cruiser would make the trip to Chalets in the Sky but what about the next morning? There would be no Cruiser V6 to tow our lorries if they again refused to start (which we expected).
We decided to play it safe: we’d head to Chalets in the Sky, negotiating some dirt roads and a few river crossings along way. But instead of staying over, we’d
continue to Camelroc in South Africa, just outside Lesotho, near the Caledonspoort Post.
On the beautiful mountain pass that leads to Chalets in the Sky, we had a moment of red mist. You see, the grey Cruiser is fitted with a trick Dobinson suspension with external reservoirs. It is also fitted with Cooper Discoverer STT Pro tyres. There was no weight on the ‘bak’.
So, on the drive up the pass, back to the main road, we gave the grey Cruiser free rein... and did it hop and skip up that pass! Keeping the turbocharger on the boil ensures plenty of horses. Even with 4WD engaged and the Coopers providing plenty of traction, you can get all four wheels spinning on the exit out of the corners.
We reached the escarpment quite a bit ahead of the white Cruiser, which was also carrying all the supplies. But watching it heading up the pass, it did seem to go unusually slow. The reason was soon apparent: a boost pipe had developed a leak, courtesy of some chafing from the power steering pulley.
It appeared as if the custommade rubber pipe had expanded a lot at the high altitude, and under the full load, causing it to come into contact with the pulley. Welcome to the world of research and development. This was exactly why we were in Lesotho. Thicker-skinned pipes are now in the, er, in the pipeline, for the upgrade, to ensure there is no more expansion (along with a loss of power). And no more contact with the pulley.
More sturdy pipes will also improve engine and turbocharger response.
We reached Camelroc just before dark, after a day spent on the road. The food was excellent, and the whisky, too. We had a right royal time.
TIME FOR SOME 4x4!
Camelroc is a place of many surprises. Not only does it offer a picturesque setting in the Maluti Mountains combined with very comfortable lodgings, it also boasts a 4×4 trail.
Heavy rains had caused parts of the track to be washed away, turning Grade 3 sections of the track into at least Grade 4s. A standard double cab would not be happy on these tweespoor tracks.
The Cruisers though, were right at home in the rough stuff. In fact, they made it look too easy. No drama, no spinning tyres; all very calm and collected. On some of the steep climbs the driver could take his feet completely away from the pedals, and the Cruiser would ‘idle’ up the incline, no worries at all.
On the steepest of the muddy downhill bits, the slightly higher gear ratio required some deft braking from the drivers. It ran just a smidgeon too fast in first gear, low range, requiring the application of the brakes
to keep the speed in check.
The Toyotas thoroughly impressed with their 4×4 ability. The combination of solid axles, lockers for both axles, plenty of clearance and articulation afforded by the Dobinson suspension, the traction of the all-terrain tyres and the D4-D engine ensure that these Cruisers can go anywhere, anytime.
By the time you read this, the N1 4×4 technical team would have been back to Lesotho with their computers to programme the Motec engine management system for the higher altitudes. And the new turbo pipes will be fitted.
In short, the research and development of the conversion will be done and the first production-ready Cruiser 3.0D4-Ds will be delivered to their new owners.
To the big question: how much? N1 4×4 says it can do the 3.0D4-D conversion for R150 000. Or, the company can supply a reconditioned Cruiser (like the white single cab in these photos, excluding the canopy) for about R350 000. Good news is that the conversion is not limited to the single cab. You can have a double cab and the station wagon converted, too.
Is it worth it? After spending nearly 1 500km driving the 3.0D4-D Cruiser, we reckon it is.
As N1 4×4’s Cliff Weichelt rightly points out, this conversion is not aimed at owners of the V8 D4-D or four-litre V6 petrol Cruisers.
“The V8 and V6 owners are happy with the power and driveability of their Cruisers. 4.2D owners, on the other hand, need more power, cruising ability and towing capability. Our conversion covers those requirements comprehensively,” says Weichelt.
N1 4×4 is not resting on its laurels either. While the first
D-4D conversions are about to be delivered to customers, the technical development team is finalising the last few details of a new D-4D Cruiser development, linked to an automatic gearbox.
What about the latest generation 2.8GD-6 mill? Wouldn’t that be an even better fit in the Cruiser, we asked Weichelt.
“That is the next step. At this time, the 2.8-litre engine is still too scarce, and too expensive, to make the conversion viable. That will change in a few years of course, and we’ll be ready to do the transplant,” explains the Perth-based N1 4×4 boss.
We conclude this tale with a little incident which happened as we arrived back in the concrete jungle, driving on Ontdekkers Road on the West Rand. Stopping at a red traffic light, we observed a pimped Nissan Navara 2.5dCi parked next to us, sporting a huge set of mags with such a thin layer of rubber between the wheels and the road, it seemed as if there was actually no rubber at all.
We noticed the driver of said Nissan curiously eyeing the grey Cruiser parked next to it. So, when the light turned green, we half expected the man in the Nissan to show this Cruiser just how fast those mag wheels really are. Of course, we obliged... and the 2.4-ton Cruiser showed that Navara a clean pair of Cooper tyres, pulling away from it at a rate that surprised even us.
We really enjoyed that. And we also enjoyed the old-school charms of the Land Cruiser. At R350 000 for a basic model without too many thrills and spills, it offers a lot of reconditioned 4×4 for the money.
Above, top to bottom: Sailing through another river, in Lesotho. A really tough 4×4 obstacle on the Camelroc 4x4 trail – but the Toyotas rose to the challenge. Below: In formation the Cruiser pickups negotiate a river crossing near Fouriesburg....
Clockwise from top: Another day, another river to cross. This one was near the Letseng Diamond Mine in Lesotho. At the heart of it all, Toyota’s 1KD-FTV engine, boasting around 170kW of power. This was the vehicle’s first high altitude test. And, at...
Opposite page: The N1 4×4 Land Cruiser 3.04-D test mule, at 3 000m above sea level. Above, clockwise from top: On the open road, the Cruiser 3.0D-4D can easily maintain 120km/h in top gear, no matter hills or dales. Sign at the top of Sani Pass…...
Below: The Cruiser 3.0D-4D test mule features a whole lot of upgrades, including an LAS bull bar, Hella spotlights, snorkel, upgraded suspension, different mag wheels and Cooper Discoverer STT Pro tyres, and a custom ‘bak’.