Fit a raised air intake to a TDCi. Not as simple as it seems, as Martin Domoney of Land Rover Owners magazine explains...
- Tools & Kit: Socket and spanner sets, Allen and Torx bits, Trim tool, Screwdrivers, Fan spanners, Hacksaw, Drill and bits, Torque wrench, Masking tape, Marker pen, Rivnut tool, File, Angle grinder with cutting disc, Trolley jack and axle stand, Hacksaw blades
- How Long? Five hours
- How Difficult? 2/5 - Easy
- Product(s): Defender Puma Sealed Air System (RHD), Safari Snorkel for Defender Td5 & Puma Tdci, Plastic Drive Rivet for Defender wheel Arch Eybrows
- Safety Advice: Wear eye protection when cutting and drilling.
Essentially, a raised air intake moves the location at which the engine draws its air from to a higher point.
This helps prevent the air filter clogging up in dusty conditions, and allows a far deeper safe wading depth when combined with extended axle and transmission breathers.
Up to 2007, fitting one was easy: the pipework from the wing vent to the airbox was sturdy and well-sealed, needing only a smear of silicone sealant to be air-tight.
Martin’s no stranger to drilling holes in body panels, having fitted a variety of accessories to brand-new Land Rovers in his main dealer days. ‘It can be daunting, but just be certain with your measurements and you can’t go wrong,’ he says.
But when the more modern TDCi engines were introduced, Land Rover decided that poorly fitting pieces of plastic trunking were sufficient to feed the TDCi with fresh air. Sealing the plumbing on these engines is near-impossible due to the push-together construction of the inlet plenum in the wing, and ducting all the way to the airbox.
So, fitting a raised air intake to a standard TDCi intake system is nigh-on pointless.
Luckily, Australian company Nugget Stuff has the solution. By removing the standard restrictive pipework and replacing it with quality plastic pieces sealed and joined by a bigger clampable hose, the problem is cured. No unwanted air can ‘leak’ into the inlet, and the engine will breathe only from the snorkel top – just the way it should be.
Take off the grilles
The first job is to remove the plastic grille in the top of the offside wing – undo the screws and lift it out. Our 110 has an aftermarket side grille which unscrews too; standard ones are pushed into place on pins into plastic grommets and can be eased out.
Unscrew intake plenum
Removing the side grille will reveal five T20 Torx screws that hold the original air intake trunking to the wing. Undo all the screws and put them aside, as the new Nugget Stuff intake comes complete with its own set of fixings in the kit.
Make some space
Jack up the offside front corner and support the weight with an axle stand. Remove the front wheel, then push all the pins out of the trim clips securing the wheelarch spat to the wing. Remove the outer parts of the clips, then lift away the arch spat.
Remove airbox hose
Loosen the clamps on the hose that connects the airbox lid to the turbocharger and wiggle the crankcase breather pipe off its barbed port, then remove the pipe. Push clean cloth into the exposed turbo inlet to prevent anything dropping inside.
Undo duct screw
Undo the 8mm screw half way along the plastic duct that also sandwiches a metal support bracket on the wing to the plastic inner wheelarch. It threads into a fixed boss in the ducting we’re removing, so we’ll have to fit a suitable nut for the other side later.
Cut the plastic
The original trunking is about a foot long. The easiest way to remove it is by cutting it in two places and retrieving the chunks. An air hacksaw makes light work of it; make a cut just before the airbox entrance and another up by the steering column shaft.
Withdraw the pieces
With the plastic cut, the centre part can be removed to allow room for the airbox-end pipe to be slid backwards out of the box’s base. The elbow can be wriggled out of the engine bay, and the wingmounted plenum removed through the top vent hole.
What a difference!
This comparison shows just how restrictive the OEM inlet tract is. The Nugget Stuff kit is not only a much larger 90mm tubing throughout, but the pipe takes a more direct route to the airbox. This increased airflow will help keep the TDCi fed with the air it needs.
Clean the area
As we’re using the kit-supplied gasket compound to seal the new plenum to the body, it’s important to make sure the surface is thoroughly clean to avoid contaminating the sealant and so that the plastic sits flush inside the wing. Wipe down the area thoroughly.
Dry fit new intake
Practice positioning the new intake plenum inside the wing. Ease the plastic inner wheelarch liner back and feed the plenum up inside, and line up the screw holes. Wind in all five self-tapping screws to cut the threads, then undo them and remove the plenum.
Lie the new plenum on a flat surface, then apply a bead of sensor-safe blue silicone gasket maker around the inlet’s mouth. This will make sure air isn’t allowed to be sucked in between the inner wing skin and plenum body when everything is all fitted up.
Attach to wing
Use the experience you gained dry-fitting the plenum to position it in place without smearing sealant everywhere, then fit all the screws again and nip them up. Pre-cutting the threads makes this easier, as the plenum won’t shift about all over the place.
Remove the airbox
Test-fit the plastic adaptor in the airbox base entrance. The box may need to be modified to allow the adaptor tube to fit snugly. If your airbox does need tweaking, remove the upper cowl and fan, then pop the box out of its grommets and lift it out.
Slot and test
With a hacksaw, cut four evenly-spaced slots in the airbox base’s intake. Open the cuts to 2mm wide, then refit the adaptor tube and tighten the hose clamp. Once you’ve got a tight fit, remove the adaptor again and refit the airbox to the engine bay.
Position the tube
Feed the flexible hose into the engine bay and sit it roughly in position. It follows a similar path to the original pipework, but make sure its extra size doesn’t interfere with the brake servo and pipes. The kit includes long cable ties for securing the hose later.
Attach to intake
Looking down through the wingtop vent hole or up through the inner wheelarch, dry-fit the flexible hose onto the plenum. When you’re happy with it, apply sealant to the plenum’s port, push the hose all the way on, and tighten the hose clamp to secure it.
Apply sealant to the end of the adaptor tube, and slide it into the airbox base ensuring the flat surface of the tube faces the engine. Tighten the hose clip, then seal and attach the other end of the flexible pipe to the adaptor. Let the sealant dry for an hour.
Rebuild the area
Remove the cloth from the turbo’s port, then refit the connecting pipe. Refit the screw through the wing support bracket and inner arch, and use an M6 nut to replace the threaded boss. Refit the wheelarch spat, top wing grille and fan and cowl.
Inspect raised air intake parts
The raised air intake uses a metal bracket to locate into the lower edge of the wing aperture – the bracket bottoms out in the Nugget Stuff one before fully home. To combat this, we cut a couple of millimetres off the metal tangs.
Trim the bracket
With the bracket secured in a vice, an angle grinder with cutting disc is used to shave 3mm off the ends of the tangs. Keep rechecking fitment in the plenum until you achieve a good fit, then file the area to remove any burrs and sharp edges.
Assemble the snorkel
Using the supplied smaller screws, attach the mounting bracket to the base of the raised air intake, and stick the self-adhesive foam gasket over the top. Secure the upper support plate to the intake with the three larger button-head screws.
Tape the area
In preparation for drilling the bodywork, apply some masking tape to the bodywork. This will prevent the paint around the holes from chipping, and will help guide the drill bit and stop it ‘walking’. A couple of strips just above the air intake hole will do.
Mark it up
Offer up the raised air intake to the wing, and make sure it’s located correctly in the aperture. Apply light downward pressure, then mark through the two screw holes in the lower body, as well as the two top support bracket slots on the windscreen pillar.
Install the rivnuts
Remove the RAI again, then drill pilot holes in the marked locations. Enlarge the holes in the wing to 9mm, then push the Rivnuts home and crimp them in with a Rivnut setting tool. You’ll feel when they’re fully set. Don’t overtighten them.
Unscrew pillar trim
Before drilling the windscreen surround, undo the two Phillips screws holding the plastic trim to the metalwork inside the cab, and remove the finisher. This will allow you to tuck the wires aside and avoid damage when drilling for the top support.
Fit top fixings
Drill pilot holes, then enlarge to 5.5mm. Apply a blob of silicone sealant to each of the holes, then start the two self-tapping screws into the windscreen pillar. Don’t screw them in too far yet, as the slotted bracket will need to pass underneath the heads.
Offer the RAI back up to the Defender, making sure the metal bracket locates properly in the intake hole as usual. Carefully slide the top mounting bracket underneath the two screw heads in the windscreen pillar; and don’t scratch the paint!
Tighten it all up
Offer up the 4mm Allen-headed bolts through the holes in the snorkel, and start them in the Rivnuts. Ensure the top bracket fits nicely, then tighten the two screws with a 10mm spanner. Fully tighten the lower screws, then push the plastic caps home.
29 Not only does the Defender look infinitely cooler with the raised air intake, we can now wade with complete confidence knowing that the engine is gulping air from high up by the roof, and the whole system is sealed all the way to the turbocharger. On top of this, the new Nugget Stuff system is a lot more free-flowing than the standard plastic trunking, so it’s a doubly-effective mod. Result!
This article originally appeared in Land Rover Owners Magazine and has been reproduced with permission. Article is written by Land Rover expert Martin Domoney.