How To Install AU Thermo Fans Into VN-VS V8

[NickVR]

How To Install AU Thermo Fans Into VN-VS V8

Tools Required/Recommended
Nice Clean Work Bench (To Fit Shroud And Radiator Would Be Ideal)
Hole Saw (A Collection Of These Is Best)
Hack Saw
Dremel Or Similar File
Small Drill (See Step #16 Otherwise A Cutting disc On The Dremel Is Fine)
Chalk Or White Marker (Chalk Is Easier To Clean Off)
Auto Electrician (For the Wiring)
Patience And Half A Day


Firstly this is the radiator that the fans will be attached to. Find the centre of the radiator and the shroud. Make sure to line these up when test fitting after every cut. Lay the fans over the radiator and you’ll see where most of the cuts need to be made. If you have an Auto, you will need to remove the Trans cooler fittings (cut off) or they can be left on. Mine were left on but the bottom one was bent out the way to avoid the fan possibly hitting it when under full load. Once all these steps have been followed, there may be some trimming needed with a Dremel or file.
Pic #1

Cut off the two end supports on the top edge of the radiator.
Pic #2

Pic #3


How it looks without the supports
Pic #4


Cut hole for Top Hose outlet.
Pic #5

Pic #6


Cut the filler neck hole. Start with a hole saw, then cut straight down the edge with a hacksaw.
Pic #7

Pic #8


It should look like this. More filing may be needed after test fitting.
Pic #9


Cut off Driver side and Passenger side lower supports. These foul on the chassis rails.
With Support Passenger Side
Pic #10

Without Support Passenger Side
Pic #11

With Support Drivers Side
Pic #12

Without support Drivers Side
Pic #13


Now cut the radiator hole out. Find a hole saw about 5mm bigger than the inlet (or 2-3mm bigger than the hose) and drill it out. Make sure to lay the shroud over the radiator and measure as good a possible the centre of the inlet. Again it may need filing to touch it up if you’re not 100% accurate.
Hole Started.
Pic #14

Hole finished.

Pic #15


These to slits need to be cut to hold the bottom of the radiator in. The brackets on the bottom of the radiator will slot into them. See First pic for the clips and pic #18 with them fitted.
Pic #16


Now to mount the top. I used Nutserts to srew into but a normal nut and bolt can be used also. Pic below is of the nutserts installed just measure and drill the holes for the shroud accordingly. The holes on the radiator are elongated so if your off by a little it won’t matter too much.
Pic #17


Now test fit everything file more where needed or you think may need more room then fit to radiator. This is how mine fitted up in the end, the bottom hoes could of done with a little more filing as it was a bit tight but fitted up ok as pictured.
Overall Fitment
Pic #18

Pic #19

Top Hose
Pic #20

Filler Neck
Pic #21

Bottom Hose (Note: The cooler outlet bent down to clear the fan, this needed to be bent up slightly as it was hard to get the clamp on the bottom hose. Adjust as needed.)
Pic #22


Now turn on the fans while on the bench to see fit they foul on anything. Turn by hand initially then once your satisfied that it is clear then power up the fans as they will flex at high speed which could cause them to hit.
If everything is fine fit back to the car and either get them up wired to the ECU or use a Davies Craig Thermo Fan Switch. Either way consult an Auto Electrician about this as you will need decent wiring for these because they draw big once at full speed.

Fitment to the car. The A/C hose may need to be bent away a little and the Charcoal canister will need to be moved or bent to make room. Other than these two things it should slot in without any issue.
Pic #23

Pic #25

Pic #26


Notes:
You will need shorter bolts for the water pump pulley. Any fastener shop or auto store can match the bolts you have, just make sure the ones you get are slightly shorter (thickness of clutch fan hub).
From what I have found the fans flow around 3000cfm. I only have one working at the moment off the V6 thermo fan plug and that is turning on at about half way on the gauge (Factory 106 ecu setting) for the other fan I will get a temp sender put in that turns on at about 90 degrees.
The sender will turn on the first fan for low speed (90 degrees) and the ecu turns on the second for high speed(106 degrees).

[Unfolded-V8]

Great guide mate , Was looking for this

[NickVR]

No worries, I was the same looking for decent pics of how this was done. That is why I chucked a thread up on it.

[shanhsv]

How do you go with the bit that the clutch fan was attached to,im told you need shorter bolts otherwise they hit the water pump or something

[Pub247]

You can use v6 water pump pulley bolts and they work fine.

But yes need shorter bolts just buy some from bolt joint or repco or the like

[NickVR]

I just replaced them with shorter bolts. Take out the original ones and take them to your local fastener shop and ask for the same ones but slightly shorter. Only the thickness of the clutch fan hub needs to be taken off the bolt.

[vscaprice98]

do u no how much cfm the au fans give m8 looking at doing mine saw ur post when im looking at doing a single 16 inch atm with 2800 cfm

[NickVR]

From what I have found they flow around 3000cfm. Twins are probably a better option because you can have one to come on at about 90 degrees then the other at around 106 (the factory computer is set at). I only have one working at the moment off the V6 thermo fan plug and that is turning on at about half way on the gauge (Factory 106 ecu setting) the other I will get a temp sender put in that turns on at about 90 degrees for the first fan. Then the ecu turns on the second if the temp gets any higher. Added this info to the first post now too.

[THE STATESMAN]

Nice work Nick will be using this in the coming weeks

[NickVR]

Good to hear Matt.

[mwemy]

what if u wanted to do this to an auto?, is there any room for the cooler hoses at all ?

[SENNY]

like my setup better :P

[NickVR]

what if u wanted to do this to an auto?, is there any room for the cooler hoses at all ?

Just. It would be very close. I have run an external cooler anyway. More efficient than the one in the radiator.

[NickVR]

like my setup better :P

So do I, it looks shinier lol. But with out spending good money on the fans to get the same CFM, I like this option better. Plus it looks factory, just what I wanted.

[THE STATESMAN]

Fitted it up today Nick good thread easy to follow and pics are good too.

[NickVR]

Good to hear Matt.

[wrx884]

good write up man this will b my next project over the weekend.

tho just wondering wen u say uve used the V6 thermo plug where is it in the bay? also ive been told u need 2 enable it in the memcal 4 the thermos 2 work through the ECU, does that mean both fans will work using the ECU or do i still need 2 get a temp sender so the 1st fan turns on at 90*? how did u go about this?

[NickVR]

Not sure if a factory 5ltr will have this plug but it should be along the rad support if there. I converted mine to a V8 so it had the plug there. If you plug the fans in to that they will turn on at 106 (I think, or what ever the ecu is set at). I have only got one fan wired into that one and will get the other fan wired up. I'll put a sender (90degree) in it and the low speed will be that one and the ECU will turn on the second one for high speed. So basically the ECU is already set to turn on the thermo fans. Hope this answers your questions.

[wrx884]

i dont think the plug is there that i can see i mayb wrong but there r wires that run along the radiator support that i assume could b them. do u know the wiring colours u used? also do u have some more info on the sender (90degrees) on how 2 hook that up, cost and where u get them from? assuming it has 2 b put inline with the ECU wires also?

[NickVR]

i dont think the plug is there that i can see i mayb wrong but there r wires that run along the radiator support that i assume could b them. do u know the wiring colours u used? also do u have some more info on the sender (90degrees) on how 2 hook that up, cost and where u get them from? assuming it has 2 b put inline with the ECU wires also?

I'll check the colours, it's just a 2 pin plug. As I said, mine was a V6 that's why mine had it there ready to go not sure if Factory V8's have them. No info on the sender yet as I am yet to fit it. When I do it I'll add it to the write up with part numbers. I am getting a local mechanic to do it as he has done a couple and said something about putting the temp sender where the knock sensor usually goes. Not sure if I heard him right though. So what ever thread that is and go to your local parts store and ask for a Tridon book, find one that has the same thread and turns on at 90 and off and what ever degrees below that.

Some people wire both the fans to the one signal from the ECU then get that adjusted to 90degrees turn on. The mechanic that is going to wire up mine said that having both come on all the time puts a strain on the charging system (alternator) and from what I have read people have had this issue. So this is why he suggested/I want them to come on independently so that the second fan only comes on when really needed.

[wrx884]

i had a play with mine and hooked them up 2 12V and yeah i see wat u mean both fans seem 2 draw a shit load of current on start up so im thinkin i may wire them both up but have a 5-10sec delay so the strain isnt so bad.

[Munz]

a VT 5litre uses a 120amp altenator due to the massive load of the thermo's
VN - VS 5L uses 85amp
unsure about the V6 amp but I'm pretty sure its nowhere over 100amp thats why its straining

[NickVR]

i had a play with mine and hooked them up 2 12V and yeah i see wat u mean both fans seem 2 draw a shit load of current on start up so im thinkin i may wire them both up but have a 5-10sec delay so the strain isnt so bad.

Yeah they do. Not a bad idea about the delay timer. Let us know how you go with that and even how you wire it up too. I'll add it to this thread.

a VT 5litre uses a 120amp altenator due to the massive load of the thermo's
VN - VS 5L uses 85amp
unsure about the V6 amp but I'm pretty sure its nowhere over 100amp thats why its straining

A small alternator on the early V8's is the main reason for the strain, you right. But when it comes time to replace the alternator I'll go to a 120amp one. But for now I'll stick to this one though. The V6's only ran the one fan so there was probably no need to go bigger than 100amp. Running 2 is a different story, lol.

[wrx884]

the 85 amp should b more than enough, ive read up so far and found the fans draw around 25-30amps each so 50-60amps in total (thats if both fans running at the same time) and its only on start up that they need this amount of amps.

Bit like ur audio just make sure u do "the Big 3" gound upgrade it'll help out a massive amount.

[walesy]

cheers for the write up! i just bought a set of AU thermos for my blown SS :-)