XF Throttle body
XF on VK[edit]
Fitting the XF TB to the plenum body[edit]
Why do it? Well, XF TB has much bigger hole in it compared to the RB30E TB don't it? Surely more air gotta = more power
This was done on a manual RB30E (in a VK).
I would assume doing it to a turbo would be pretty much exactly the same.
Apparently there are 2 different types of XF throttle bodys.
I have no idea what one I have. It came off a 1979 fuel injected ZK ford fairlane.
Shown below is the one I used.
Ok, now to start off with, take the top part of the plenum off completely from the intake manifold (refer to a Gregory’s manual, or just keep taking stuff off until you get it)
Take off the old VL TB.
Get XF TB and modify the holes so they are closer to the center. You can do this using a dermal sort of tool, or a rats tail file.
Flatten edges of the TB to get bit more room for head of the TB screws using a small flat file
Grind the heads of the TB screws so they are smaller diameter.
Bolt XF TB onto the plenum and make sure all the bolts that hold the TB on can screw ALL THE WAY in.
Tapering the plenum[edit]
Now you need to match the plenum to the TB. The BEST way to do this would be to weld up the valley around the TB flange on the plenum so you can have a straight hole going into the plenum. If you don't want to do that, you will need to taper the TB hole in the plenum to try and match the XF TB. This is what I did.
Ok, now with your XF TB bolted on, open the butterfly and using a fine point marking pen of some type, draw a circle of the area that needs to be tapered to.
Take off the XF TB, and you will see what needs to be done.
Get out the good old dermal and start having fun. Make sure you make the line disappear to make a perfect match to the TB. Remember, a little bit to big is less restrictive then a little bit to small. I used tungsten carbonate bit to take majority of the metal off, then used a stone bit to even it out, then used sandpaper wheel to make it smooth.
I found it was easier to just taper it in on a fairly sharp angle first, then from there, work your way around grinding bits off to make the hole bigger, and constantly checking you don't take to much and go completely through the edge.
When finished, make sure to clean the plenum out perfectly because you don’t want heaps of those little metal bits going into your motor. I used a can of spray degreaser (works better then normal stuff you have to splash around yourself) and cleaned out the inside of the plenum with that, and then good hose out with water.
Your plenum should like something like this now (not cleaned yet in the photo)
Now you will need a gasket. Take the standard RB30E gasket, and put on how it would normally go on. (put it in so its bolted between the XF TB and the plenum). Now do what you had to do to mark the area on the plenum to be cut, but marking on the gasket this time. Take off the TB and cut off part you don't need from the gasket. You can now assemble the TB back onto the plenum with the gasket in it. Do the TB bolts up tight while it's all off the motor because it's a lot easier to do now.
The 2 little pipes at bottom of XF TB[edit]
With the pipe that goes to the charcoal canister that originally went to the old RB30 TB, connect it to the XF TB pipe that has a green ring around it. That pipe goes to a very small hole on the air filter side of the butterfly in the TB. Both the RB30 and XF TB’s have this little hole. As for the red hole, I could not figure out where it went, and I couldn't blow any air through it, so as far as I could figure out, it does nothing. But just to be on the save side, block it off.
The water line[edit]
With the water lines that use to run through the old TB, you need to make them connect. I did this by removing the old bits of pipe, and putting in a short piece of air hose in between instead. Maybe dodge, but it works.
Now you have 2 big holes in your XF TB that you need to do something with. You can either block them off, or use them. In my case, I blocked the one on the top. I removed the pipe bit by grabbing it with pliers, and then turning it and pulling it out at the same time. And with the bottom one, I used it to connect to the top of my rocker cover, and to my idle speed control valve using a copper plumbing bit as shown below.
Please note that in this picture, I have both the pipes removed. I ended up putting the bottom one back in later. The pipes will be where the arrows are pointing to. You can see on the inside of the TB where the holes are.
This is what I ended up using to connect my pipes together. I recommend getting one that is 3/4" all the way with a 1/2" tap off it that goes to the rocker cover.
For the second top pipe, I blocked it off. The size of the hole is very close to 15mm. So I went searching for a 15mm welch plug. Such a thing does not appear to exist. So you have some choices here. When the TB is off the motor, drill the hole out to a bigger size, you could leave the pipe bit in there, and try and find a big rubber block bit to put over it, or you could remove the brass pipe bit, and get a 16mm plastic thing that you nail onto the bottom of tables and chairs do they don't scratch the floor, and wack that in. (yep, sounds dodge eh?) I have no recommended ways on how to do this. You will need to work out your own way.
The throttle cable[edit]
Now to get the throttle cable to work properly, you need to shorten it. However, I got around this by spacing out the bit of metal that holds the throttle cable adjuster bit. (You will require longer bolts for that bracket to do this) I think they were 80mm long M8 threaded bolts that I used. You will need it to be spaced about a extra 40mm away.
The TPS[edit]
Now to get the TPS working correctly, you need to change 1 of the wires around on the RB30 plug, and completely remove another one. BUT this will ONLY work for the manual. If you have an automatic, you have some extra plug and I got no idea on how it works because I don't have one to test.
How the TPS on the manual RB30 TB works, is it has a little switch in it, and when the throttle is closed, this switch is connected. When moved from idle, switch is an open circuit (not connected). On the RB30 TPS, it is the top 2 pins that do all this. The 3rd pin at the bottom does nothing as far as I can work out.
The XF TPS works exactly the same as the RB30 TPS, however, there is another switch, and when the throttle is almost completely open, this switch will connect the top pin to the centre pin. When completely closed, it will connect the bottom pin with the centre pin. These are the ones we want to use.
Now what you have to do is on the RB30 TPS plug, try and remove the bottom wire from the plug (so it comes out with its little metal bit also). You do not need this wire, so either chop it off, or just tape it up out of the way. Now you need to remove the top wire (with metal bit also) and push that into the bottom part of the plug.
Hope that made sense because it's kinda hard to explain and I didn't take any pictures of the process.
The piping[edit]
Now you need to do something about your intake piping as the XF TB is much longer then the RB30 one. Get some nice chrome looking 3" pipe to make good use of your need big new TB.
I used the 3 inch piping from a VN / VP commodore. To do this, move the AFM up near the TB, and get a flange bit that connects onto the top half of a VN airbox (because its 3") and bolt it onto the end of the AFM. Use the top half of a VN airbox also for your airbox, and connect the intake piping on. You will need to cut the plastic pipe shorter so it will fit in.
Stuff I got from a VN commodore.
Completed
Compiled by
Pastical - Calais Turbo
TPS fix[edit]
This is to help the people who do the XF TB conversion and have a bit of trouble with the TPS as I found today with these problems similar to everyone else e.g. throttle sticking with custom brackets when using the Nissan TPS, or having to chop or reposition wires to run the XF TPS (I did not want to cut or reposition wires).
My fix was that if you file back the 3 guides off the XF TPS unit where you plug it in you can turn the plug upside down, thus putting the top wire at the bottom.
I guess where it explains to chop the wire you could but I left it there, if it does nothing what harm can it do.
-DRFT-ME
Or you could use ka24 T/B i think its only tiny bit smaller than XF... not sure and is exact same stud pattern and pretty sure the R31 TPS bolts on.
For the XF people have bolted a plate to where the XF TPS bolts to then bolted the R31 TPS to the plate
-runnin4life
Just got to get the KA24 off a Ti model and it has the twin wheels. although I took the throttle wheels off my RB30 T/B because they look better..........cruise control works a treat too.
While you're at it, may as well bypass the heater hose that runs through the T/B. keeps an indeterminable amount of heat out of that area Cool back o/t. KA24 is 64mm and direct fit, down to the TPS. XF throttle is a 68mm item and a bit more work involved.
Here is a photo of the KA24 installed, including cruise.
You can also see where I've bypassed the water line so it doesn't pass through the T/B.
File:Throttle Body Bootinstall015.jpg
-SMOKEY