What’s in the Box ?
System Benefits
Recommended Upgrades
Development Process
Where did it start ?
Where do I get it ?
The Madman GEN2 VNT kit is the second generation of our Variable Nozzle Technology turbo for the Land Rover 300Tdi engine.
A direct replacement to the stock turbo assembly, requiring no cutting or modifications
Uses a common off-the-shelf turbo for Turbo brand choice and ease of repair or replacement.
The Gen2 VNT kit will make your vehicle a pleasure to drive. Painless acceleration and cruising will leave you looking for that elusive 6th gear.
Yes, Yes, that’s a great big hole in the engine block, (It wasn’t us)
We’re not sure what happened here, but it’s better to make plenty more torque at low RPM than to rev the hell out of your 300Tdi, High rpm kills engines (Especially old diesels) that’s why we choose to keep the rpm low and torque high.
What’s in the Box ? – Kit Contents
3 Piece Cast Stainless Steel Manifold
Cast Stainless Steel down pipe
Teflon Braided Oil drain and Supply hoses
High Tensile 8.8 Mounting hardware:
- Tensiloc Flanged nuts and bolts – Self Locking
- Longer replacement manifold Studs – To give a better grip in the head and prevent thread pulling out.
Adjustable, Rebuildable Billet alluminium Actuator (Piston Type) with 3mm Stainless Steel Actuator Bracket
Turbo Inlet Adapter
Particle filter with stainles steel bracket and tubing
High quality gaskets
1/8 NPT Port for your EGT probe
Stickers !
All packed in a tough shipable box so that it arrives safely.
What’s NOT in the Box ?
You will need to buy a Turbo – Either from LP4A (They stock the JRONE brand with warranty) or from any other turbo supplier.
The perfect turbo is the Original Garrett 704361 turbo, these are becoming both scarce and expensive.
Luckily, there are many other brands making the same turbo (A copy) some are better than others, price is often an indication of quality, all other things being equal.
We have not had the opportunity to test other brands yet but have plant to do so in months to come.
Simply ask the turbo supplier for a GARRETT 704361 Turbo The part number supplied will be in the format 704361-xxxx, the xxxx are later revisions of the same turbo and are irrelevant as all suffixes will work just fine.
Make sure you get the turbo with the inlet gasket and oil drain gasket as they are not in the kit.
Designed for a Purpose
3 Piece Manifold + Downpipe
The manifold was designed a 3 parts to reduce any chances of cracking or snapping manifold studs. The original turbo was designed in this way for this purpose however the original manifold had a high tolerance fit which occasionallyled to leaking.
This assembly has an extremely fine interference fit and WILL NOT LEAK
The turbo down pipe is such that the original turbo exhaust fits straight on reducing the number of unique parts in the system.
Actuator Control
The vanes are controlled by the exhaust pressure rather than the boost pressure.
The exhaust based control reduces exhaust back pressure to a greater extent than the boost pressure driven actuator, it also reduces to zero boost peaking and boost oscillation under heavy acceleration.
The logic is simple in that the feedback loop to control the exhaust vanes is shorter. Exhaust pressure directly controls the vanes whereas using boost to control the vanes means the result of the previous exhaust adjustment must first processed by the combustion cycle before being assessed again by the actuator.
The Filter serves as a soot trap to keep the actuator piston clean, this needs to be blown out at each service.
HOT or COLD
control ?
|
HOT |
COLD |
| Exhaust gas pressure does not exceeding 1.5 bar | Exhaust gas spikes over 2.5 bar in some situations |
| Lower exhaust pressure results in greater power and ‘ligher’ engine feel. | Higher Exhaust pressure makes the engine feel duller and it has less power. |
| Boost buildup from zero to 1.2 Bar is totally smooth, reaching 1.2 Bar without overshooting. | When boosting to 1.2 Bar, Boost spikes to 1.7 Bar, drops below to .8 Bar then spikes again to 1.4 Bar and finally settles at the targer of 1.2 Bar – This ringing, or oscillation can be felt by the driver and is clear on a boost guage. |
| IF the turbo vanes were to become stuck closed (due to foreign body or coking( the external pipework will burst bringing your attention to the problem preventing further damage. | IF the vanes were to become stuck closed, there would be zero indication of an issue and it is possible to damage the internals of the engine if driving continues. |
| This method is more expensive and requires maintenance of the particulate filter | This is the cheapest option and requires a simple pipe to the inlet manifold. |
|
A misconception is that the filter and piping will get hot and melt or burn. NO, this is false as there is virtually no air flow in this tube, regular rubber tubing and a plastic fuel filter can be used under all conditions. |
You Choose
The response you get with different configurations is subject to tuning and fuelling, as well as driving stile. The Madman Gen2 VNT kit is supplied with the exhaust based control, however, if you choose to keep with the conventional method, you simply fit the actuator tube to the inlet manifold. Try both options and pick the one you like. You may need to adjust the boost actuator or fit the green spring to get a good response from the cold side control.
FULL TEST DATA WILL BE POSTED HERE SOON
System Benefits
LONGEVITY & RELIABILITY
The system has been built as well as (and better) than the original Land Rover assembly.
Oil supply and drain pipes are teflon braided hoses (Not silicone tubes and hose clamps as before)
The studs and bolts supplied are high tensile 8.8 grade and are longer than OEM, giving a much better engagement in the head threads, thus increasing gasket sealing and preventing the threads from pulling out.
Nuts and Bolts have serrated flanged heads for a firm self locking effect.
The turbo itself is a common off-the-shelf turbo and not unique to the system. This gives you the option to choose your turbo brand and makes it internationally obtainable and easy to replace or repair.
No modifications to any hoses or other parts means the engine can be returned to original if the vehicle were to be sold original parts can be installed in an emergency situation.
The general appearance of the system fits in with the OEM appearance making it a neat fit on original vehicles and custom vehicle restorations, not looking out of place at all.
POWER IMPROVEMENTS
TURBO ONLY – no Fuelling adjustments:
As a direct replacement without any fuelling adjustments or any other component replacements, there is a significant driveability improvement. This is brought about by the nature of the VNT whereby the turbo acts as a small turbo for low rpm/load boosting sooner and a larger turbo for higher rpm/load scenarios enabling greater exhaust gas throughput. The added air volume from the turbo will reduce any smoke that there was and effectively make more power without any increace in EGT.
With stock fuelling, our tests have shown EGT peaks at around 660 Degrees C with no visible smoke and AFR readings above 20.
There is useable boost from 1300 rpm this means you can remain in a gear longer under load or pull out of a situation easier without the need to change down first. In traffit or in an off-road situation.
This option would be the only option if you live in an emmistions controlled environment where you are not permitted to adjust your fuelling.
INJECTION PUMP Compensator Alterations
(Boost pin, diaphragm and Star wheel):
This would be the recommended option for most people looking for greater power output. Additional fuel ban be added by adjusting the compensator components on the top of the pump and will add alot more excitement to the drive and generally achieve the performance level you were expecting.
The added fuel will raise the EGT, but not much more than the levels obtained by the original turbo assembly. A Madman EGT monitor is well advised.
TOTAL FUEL
If max power is what you are after you will need to add even more fuel than the compensator settings will allow. This involves adjusting the injection pump main fuel screw (slightly at a time) and readjusting compensator settings to get a suitable balance of power, smoke and EGT.
This type of tuning will only be done AFTER external upgrades have been done – see the section on physical upgrades.
SPEED
Will this kit make your Land Rover go faster, yes and no:
The engine will be more powerfull (Depending on your state of tune) and this power will enable you to maintain speed on hills and therfore your average trip speed WILL be higher and the drive more pleasant.
To achieve a higher cruising speed without running at hight rpm all day long you would need to change the gearing in any of a number of ways, such as changing the transfer box ratio, fitting an overdrive, changing out the diff ratios or fitting larger tyres, each has its pros and cons. One thing is certain, the vehicle will have more power to manage the higher gearing than before.
WHAT DO CUSTOMERS SAY ?
Rene
Wow! So excited and as always impressed by The entire kit. Such attention to detail. always the very best method chosen of operation to accomplish the function. also well finished right down to the packaging
Nico – Rustenburg
‘Alles maklik geinstalleer, Ek ry nou verskriklik lekker. Al die rook is weg, baie dankie’
Donovan
Looks Amazing – My (Gen1 kit) is still running. It’s almost on 400k now. I have 2 other 300Tdi’s for this (gen2) kit
John
It’s a thing of Beauty…
Marc – Adventure Motors
‘That Landy goes so well ! Plenty power , no smoke good EGT, it drives so easily !
The late Rob Miller – REM Bros
“Looks Propper”
RECOMMENDED UPGRADES
Air Filters
It is highly recommended to replace the air filter in 300Tdi Discovery models with a high flow filter. In our tests we have had the ADG945 type filter burst inwards, releasing its dust load into the engine and destroying everything in it’s path, this is worse when moisture is added.
For hot and dusty climates, a round Donaldson type filter is recommended, for colder, cleaner climates an aftermarket filter *may* suffice.
Recommended Donaldson filter for Discovery:
- Housing: FPG070006
- Main Element: P772579
- This filter also has a safety element, which is not used under normal conditions.
The larger housing suggested for the Defender is too large to fit the Discovery.
Note that additional piping will be required to fit the filter and the windscreen washer may need to be replaced with a smaller unit.
Defender:
The regular filter is suitable for standard tune up to 1.2 Bar boost, however we recommend a filter with full mesh wrap rather than partial mesh as seen below.
It is clear to see the potential airflow on the full mesh filter is much greater that on the sheet metal filter.
ADG942
ADG945
ADG505
FPG08-2503 Filter
Exhaust
We recommend the catalytic converter be removed (If fitted) as well as the large centre mounted silencer. The small rear silencer can be retained if preferred, subject to personal taste.
This would be ok for most aplications.
If preferred, a free-flow silencer can be fitted to reduce droning.
A larger diameter pipe can be fitted for higher performance projects (2.5”)
The 130 used for testing has no silencer boxes at all, it’s not loud, it just sounds more like a truck.
Charge Air Cooling
Intercooler
The standard intercooler does a fair job in a standard tune up to 1.2 Bar and can be used safely.
A larger side-mount intercooler will improve performance without affecting any other parts of the vehicle but improvements are not huge.
A front mount intercooler is the ideal upgrade, it will allow for higher boost and additional fuelling greatly increasing available power, however there may be additional work required especially if an aircon condenser is fitted.
There are various models on the market.
Alisport 300tdi Side
Alisport 300Tdi Front
Airtec 300Tdi Front
Airtec 300tdi Side
Cirrus Coolers 300Tdi Side
Water-Methanol Injection (WMI)
WMI (Water Meth injection is a process where a 50/50 mix of water and methanol is injected into the air stream under high pressure to atomize the mixture which is then fully evaporated into the airstream. This greatly reduces the air temperature, increasing the air density reducing EGT and increasing power. (Same effect as a larger intercooler)
The system is activated by a pressure switch or Madman monitoring system when the pressure exceeds +- 0.9 Bar or when EGT increases. The main benefit is that it has the ability to cool the inlet air to below ambient air temperature. Additionally it requires minimal alterations and can be turned on and off as needed, it is however, a consumable and is used at a rate of +- 5L/100km when active. This with a larger intercooler will compound the cooling effect for the coolest possible inlet air.
Coolboost WMI Kit
2.8 Power Stroke Injectors
Simply turning up the main fuelling screw is not ideal as the injection pump can only deliver so much fuel before working outside of it’s limits.
One of the issues is that added fuel increases the injection time, this means that at a certain point the injector is delivering fuel after the piston has moved out of ‘range’, this does not add much more power but can damage the piston and cylinder walls quickly, as well as add egt.
The Injectors from the HS2.8 Powerstroke can be fitted to the 300Tdi, the benefit of this is that more fuel is delivered quicker reducing the chance of running out of injection time typically helping higher rpm power and egt.
A penalty is paid by a less responsive off-idle condition – These are recommended for higher rpm, high power applications and used only after all other upgrade avenues have been taken.
These injectors are no available in South Africa but can be imported on request.
Radiator and Cooling
Our testing did not raise any requirements for upgrading the cooling system.
We can advise to use an alluminium radiator, clean intercooler and ensure your fan and viscous hub are in good condition.
fan and viscous 300tdi
tdi radiator assy
It all started in 1992
It all started way back in 1992 when I was inspired by an older Land Rover Club member that had a low pressure turbo on his 2.25 Petrol engine. I felt the need to experiment
With zero knowledge, I successfully turbocharged my Land Rover Series 3 SWB 2.25 Petrol using a Nissan Exa Turbocharger in a blow-through carburettor configuration with a home made fuel pressure regulator and alot of unskilled backyard engineering.
The turbo Shorty lasted quite a while until one day my heath-ribinson oil cooler connections came adrift and enptied the engine oil rather quickly onthe way to work one day. I subsequently fitted a 2.25 Diesel…? yes, a rather odd choice from Turbo petrol to N/A Diesel, but that is where the Diesel story started…
2001
Fast forward several years, I came up with the idea to fit a GMC 6.2L V8 Diesel to Shelley’s Range Rover. That was another learning curve and ultimately ended in success, but I was not sold on the whole ‘engine conversion’ thing and looked back at original engines and making them better than original, thus keeping things closer to standard, easier to maintain but enjoying better performance.
while I operated LandyOnline Workshop and I wanted to improve the power output of my 300Tdi 110 Workshop/Competition Landy. First try was 2012 G1 was 2013
2012
During the operation of LandyOnline Workshop (2002-2014), I wanted to explore how to improve the power output of my 300Tdi 110 Workshop/Competition Landy. The first try was with a 2.4 Puma (Tdci) Turbo and vacuum actuator. I used this setup for the 2011 Defender Trophy in Venda.
2013
,The first try showed promise, so I set to work to make a system for re-sale and the Gen1 VNT Kit was born. It used the same turbo as on the Gen2 Kit but the turbo phasing was changed to suit the manifold layout, this led to a uniqueness in the turbo which was not ideal. Approximately 55 of these kits were made (by me by hand) and sold upto around 2016.
The kits were very successfull with 55 very happy customers.
This same engine shown here fitted to the 110 Pup that I used for the Gen1 development is the same engine I have in the 130 now which was used for the Gen2 Development.
My wife’s Disco still has the Gen1 Kit fitted today.
So…what was the Torque and Power like ?
AS-IS Defender 110
This was an ‘as-is’ 300Tdi Defender 110 that came in for the upgrade, this vehicle was take for a dyno run to get the first Test, we fitted the Gen1 kit tuned the engine and the result is Test5. It is clear the engine was not in the best condition but the improvement is substantial.
King Julien - The Workshop Landy
This was the best test achieved (TEST 20), The engine had a larger air filter, standard pin, standard intercooler, snorkel and increased Main fueling….it *might* have had Water-Meth injection, not sure.
Gen2 VNT Installation - Solihull 4WD - Randburg, South AFrica
From 47.6 Kw and 166 Nm @ 2500 RPM
To 66.3 Kw and 220 Nm @2500 RPM (166Nm @ 2000)
Where Can I Get It ?
Exclusive Distributor
Landy Parts for Africa has been appointed as the exclusive distributor of the Madman Gen2 VNT Kit in South Africa. Pricing from them is Nett pricing, same price for everyone.
Gen2 VNT Manifold kit: R 14375.00 excl Vat
Jrone Turbo: R 6275 excl Vat
If you are outside of South Africa, please contact us directly.
We are seeking international distributors
USA: We will have stock in the US Store in early January 2026