- 1 NO to K&N
- 2 Airbox Filters
- 3 Airbox Intake Routing
- 4 Airbox Options
- 5 Airbox CFM Math
- 6 Air flow Calculation
- 7 Coolant System
- 8 Aux Oil-Cooler Modification
- 9 Heater Hoses
- 10 Comments
NO to K&N
Read this first from TDI Club about Slica
Using a proper filtering air-box & filter is critical to a proper running engine. Knowing your engines requirements really helps suiting an airbox!
1.6na (CS) - 210cfm
There's no real benefit to upgrading the 1.6na engine if you have it intact. It won't be till you upgrade to a different engine for when you need to look into it.
1.6td (JX) - 125cfm
These engines came with a 125cfm airbox & filter
These generally use the same as the 1.9tdi (1z/AHU/ALH) counter-parts.
1.9tdi (1z/AHU/ALH) - 210cfm
These engines came with a 210cfm airbox & filter
Airbox Intake Routing
A good layout for the Airbox & Intake is shown below for turbo diesel setups with an IC in the rear PS pillar. If you relocate your starter battery and clear that area up for an airbox, you got a great path of air.
Air comes into the passenger side vents and feed air into the airbox of your choosing. The driver side air vents bring air into the A2A IC placed.
Do NOT use a K&N air-filter for your air-box at all costs. It doesn't filter well enough for the TDI. More information here
There are a few common filter housings used.
- G065411 with 2.5" inlet & outlet ports @ 110CFM
- G065433 with 2.5" inlet & outlet ports @ 120CFM - This seems the most common used and I myself used it till I upgraded to a custom setup. If doing a Donaldson one should consider getting the 150cfm varients.
- G070018 with 3.0" inlet & outlet ports @ 125CFM
- G070020 with 3.0" inlet & outlet ports @ 150CFM
- G065424 with 2.5" inlet & outlet ports @ 110CFM
- G065432 with 2.5" inlet & outlet ports @ 120CFM
- G070017 with 3.0" inlet & outlet ports @ 125CFM
- G070019 with 3.0" inlet & outlet ports @ 150CFM
The reason for the starter battery relocation was for the Donaldson G065433 air-box with the bracket p/n H0084412 or H008444
I wanted to get the intake routing as direct as possible with my setup.
Using a passenger fabbed snorkel coming into thje passenger side, putting the Donaldson as shown below, makes it way easier and direct for the hoses.
NOTE: I had to remove the tabs off the old DV snorkel and those foam bits. It was then able to fit into the passenger side with some wiggling effort with the 3" hose. It WILL go, but be patient and take your time. For securing the hose to the snorkel use Rescue Tape!
Installed view without hoses, yes the clips are functional! The lower is a little bit tight, but it works!
This gives some idea of how much hose clearance I'll have. The taillight is installed in the last photo to get a reference:
This is the snorkel and 3" hose attached. It was a bit to work the 3" around the snorkel, but it WAS possible!
This is the snorkel wrapped with Rescue Tape to attach the hose. This is the BEST tape to use compared to "duct-tape". No substitution for this project!
This is how the snorkel will look when test-fitting. You'll need to remove the tabs/foam for it to fit
Snorkel hose is now attached to the Donaldson as shown in this photo looking in from the rear light
The red one is going to the turbo. It's a tight fit! But it's doable! It's 2.5" on the Donaldson side to 2.25" on the metal pipe
Jaguar XJ6 1979-87
I haven't done this personally, but others have. Here are some photos
Installed in a vanagon
I'm currently in the process of making a TDI Carbon Fiber air-box that wlil go where the Donaldson goes. The best airbox for the TDI engine! Keep posted ;)
Airbox CFM Math
First let's put some referenes up front.
Let's get some basic numbers
- 1 bar of pressure is 14.5psi
- 1.25 bar of pressure is 18.1psi
- 1.50 bar of pressure is 21.7psi
- 1.75 bar of pressure is 25.4psi
- 2.00 bar of pressure is 29.0psi
Air flow Calculation
Displacement: 1896 cm3 or 115.7 cu-in
- Air Capacitycfm = (displacement x RPM) ÷ (1,728 x 2)
Note: Air capacity is a function of displacement (volumetric capacity) and engine speed (RPM). The displacement is divided by 1,728 (the number of cubic inches in a cubic foot) to convert it to cubic feet. The RPM is divided by 2 because the engine only intakes on every other revolution. The formula can be simplified as follows:
- Air Capacitycfm = (displacement x RPM) ÷ 3,456
Let’s calculate the airflow requirement for a stock AHU VW TDI engine of 115.7-ci with a torque peak at 1900 rpm and a maximum engine speed of 4000 rpm.
NO BOOST examples:
- CFM = (115.7 x 1900) ÷ 3,456 = 63 cfm at the torque peak
- CFM = (115.7 x 3000) ÷ 3,456 = 100.4 cfm at the torque peak
- CFM = (115.7 x 4000) ÷ 3,456 = 133.9cfm at the power peak
18psi max boost'
- 1.2bar = 18psi
- CFM = (115.7 x 1900) ÷ 3,456 = 63 cfm at the torque peak x 1.2bar = 75.6cfm
- CFM = (115.7 x 3000) ÷ 3,456 = 100.4 cfm at the torque peak x 1.2bar = 120.48cfm
- CFM = (115.7 x 4000) ÷ 3,456 = 133.9cfm at the power peak x 1.2bar = 160.68cfm
29lbs max boost - crazy fucks!
- 2.0bar = 29psi
- CFM = (115.7 x 1900) ÷ 3,456 = 63 cfm at the torque peak x 2bar = 126cfm
Middle 3k: :CFM = (115.7 x 3000) ÷ 3,456 = 100.4 cfm at the torque peak x 2bar = 200.8cfm
Power peak: :CFM = (115.7 x 4000) ÷ 3,456 = 133.9cfm at the power peak x 2bar = 267.8cfm
NOTE: Before you start disconnect the negative wire to the starting battery!
NOTE: This assumes your water-pump & thermostat are good, if not that should be replaced! If not here you go for p/ns ETKA If you're doing a conversion soon, may want to hold off on the water-pump till the new engine ;)
The van is HOW old? And how important is a coolant system to a functioning engine? The answer is VERY to both questions!
Revamp your coolant system!
- New Radiator p/n 068-121-253E
- New Radiator Fan p/n 165-959-455AM
- New Radiator Temp Switch p/n 251-959-481K 85,93
- New temp sensor p/n 049-919-501
- New radiator hoses p/n 251-121-083H & 251-121-082
- New SS Coolant Pipes if you can get them!
The 82 & 83' diesels have a radiator setup that should be overhauled to the newer setup.
The main differences between this setup compared to the later vanagon radiator setup is the following:
- Newer radiator shroud (metal) non-ac from an 85-90 van to be safe. The stock diesel one is plastic and not usable
- Newer 85+ radiator mounts
You can use an AC fan-shroud, but you'll need to make an adaptor as shown below.
- Newer lower radiator support brackets 85-90. It doesn't matter if it's AC or non-AC
- New radiator hoses; the return hose is different between the diesel vanagon and the newer setups
So, you may be trying to locate an alternative to the DV crazy hose setup.
You can get new silicone made hoses by GeeBee
These were the references I used to get the job done on my van and help another with theirs.
This was pretty easy. Once you put the new style brackets (they are a C shape almost) and use the same 13mm hardware as your existing.
The only thing you need to fabricate, is the top bracket to hold the radiator in. This can be done by a simple L bracket for a drawer or something. It'll be aparent when you look. Like this:
Here is a photo of what the "newer" 83+ style brackets look-like
Radiator Fan replacement
p/n 165 959 455AM
You will need to use an 85+ radiator shroud (metal) for a non-AC Vanagon.
However, if you can only find an AC based shroud, you can still use it.
You just need to make an adaptor plate for the non-AC fan to fit the AC shroud.
This can be done tracing the File:Diesel-acshroud-template.pdf template. I originally used a bucket lid when I discovered this issue; stoned engineering tricks!
Original bucket-lid! This made me 2000 miles from STL to LA and then some.
Template marked on sheet-metal; if using thin sheet-metal double up!
Metal sheet-metal version; NOTE: you should test spin the blades to make sure it clears. It SHOULD, but better to test before giving live power!
My original bucket-lid version installed ;)
Radiator Fan Electrical
Old Radiator Electrical Setup
So, with the new setup, you'll have only one switch and three wires.
The four wires you see in the photo should be:
two heavy wires - low fan setting
two thin wires - high fan setting trigged from the relay
You'll connect female quick disconnects and connect to the temp switch via a pig-tail.
For this pigtail, I recommend 10g wire with the colors Red, Black, White.
You will need a multimeter or something to determine which wire is hot
Of the two thin wires the one which is LIVE (HOT) is not used anymore. This can be trimmed, cleaned up, bent back, and taped up to not be used anymore.
This leaves you with THREE wires:
- 2 heavy wires
- 1 thin wire
Now, at this point you want to see which of the two LARGE wires is LIVE (HOT)
Now, you need to build your pig-tail
- Heavy wire with constant +12 goes to pin labeled + on the temp switch (towards the bevels on the end) - RED
- Heavy wire to fan low speed connection goes to pin 1 (center of temp switch) - BLACK
- Light wire to fan high speed relay control goes to pin 2 (furthest away from bevel end) - WHITE
This can be seen in the photo below:
This is how the pig-tail was done when installed
Okay, at this point we'll want to hook up the actual radiator fan.
Cut off the old connector for the rad-fan off the current wiring harness. At this point you'll want to put female quick disconnects on the wires:
The new fan pin-out is:
Now your old plug had three wires:
BROWN - GROUND
R/BK - LOW
RED - HIGH
Place female quick disconnects on those and plug into the new fan!
Radiator Fan Electrical Testing
At this point you want to test your circuit for the LOW & HIGH fan.
Disconnect the three wires from your radiator temp-switch that you installed earlier with the new pig-tail.
Get a short piece of wire to jump across wires for testing.
If you short the R & B you'll get LOW
If you short the R & W you'll get HIGH
If that works then your circuit is good! Just hook up the wires back to the temp switch!
1x 2"x30" black pipe(pre cut piece sold at homedepot)
1x 2" to 1 1/2" rubber reducer with clamps
1x 5/16" brass hose barb
10ft of 5/16" silicone hose, couldn't get any smaller quanity.
cost me $15 bucks to make it, plus it looks cool sitting in my garage.
Coolant Level Sensor Upgrade
Most 82' & 83' diesel vanagons had no coolant level sensor like the later years. This diagram helps implement it;
Aux Oil-Cooler Modification
The default DV aux oil-cooler doesn't allow for constant flow of coolant. Only when the thermostat opens.
This is kinda silly since all the newer diesels implemented a better setup.
Therefore, this SHOULD be REQUIRED for all DV owners.
Seeing is believing like they say. It also helps visualize what has to happen. This was indeed the case with me!
Karl M. @ Westy Ventures drew this up to explain what's required for the modification that he explains in TheSamba post.
For the Tee you can search ebay for sometrhing along: Coolant Hose T Fitting Radiator Hose T Fitting Hose Splice 1" X 1" X 5/8" VW has one under p/n N90693001
Which should look like this:
If you prefer a Y based solution, go to Heater Craft
For attaching the hoses make sure to use rolled-edge SS clamps, as they don't cut into the hose as traditional hose-clamps do.
Fot the 1/4” restrictor you can use a fender washer with a 1/4" hole and a 1.25" OD
While doing the coolant pipes/hoses, you should also replace your heater hoses. Mine were so soft/brittle that my thumb nail could puncture it!
I had no rear heater or fun accessories, it was just a 5/8th heater hose about 27ft get 30ft to be safe. Also, get a proper 1" to 5/8" reducer for your cylinder head flange.
This hose reducer is for the end of the cylinder head where the 5/8" hose goes into a 1" barb. Many will "squeeze" the 5/8" onto the 1" which is a BAD idea. You're likely to split the hose at some point. I actually helped a couple in their conversion in a diesel vanagon with this exact problem. Get the reducer!
Now, in the photo below, the one with the tape band goes to the cylinder head. The one with the stock control valve goes to the coolant tank hose.
Note, that I also have a valve on the right side, a mod from BlueHighway Vanagon.
With the valve installed, the flow of hot water to the heater core can be completely shut off, allowing cool, fresh air to be circulated through the system.