I have tried search and cannot find one but imagine there must be a thread somewhere!
Can someone post a link or pictures on removal of the double throttle system from the 20B throttle body and what other bits can be removed and blanked off in the process of doing a single turbo conversion.

Thank you
Lee

 

I am assuming you are talking about removing the 1st set of throttle plates on the throttle body.

Its nice and easy pretty much see whats attached to it and start undoing nuts and bolts.

you will be left with a couple of holes where the throttle shaft would have gone through that you will need to blank off, you can do this by tapping the hole and screwing in a grub screw.

make sure you do all this with the throttle off the engine.

 

That would be the ones. So the aluminium body on the left side (front) which has the waterpipe going to it can come off too and be blanked? I just wanted to double check if everything can go of not. I have done it on a 13b ages ago and couldn't remember what I did!
Is there anything else I can do away with while I am at it. Or simple mods to increase power down the line maybe? It's going in an FD on a microtech ECU if that helps?
Cheers
Lee

 

Yes that can be removed and blanked, and underneath there is an emissions unit bolted to it (when unbolted leaves a diamond shape flange) that can be removed and blanked too.
I recommend leaving the dash pot on the right hand side in place.

You can port the throttle body, I don't have any evidence of what it will yield for you but heres what it looks like http://www.rotaryheads.com/pics/porting/tb-finished.jpg

As an added note all the throttle linkages and butterfly's etc are very sensitive to the amount of torque to which they are done up too, over tightening them can cause issues like sticking shut, being stiff through its total movement etc.

I'm sure since you have don this before that your well aware of that though.

 

Hmm, I'd imaging it would be similar to any of the others as far as the first bit goes... Here's one for the 13B, I guess just apply the various changes then?
FC3S Pro v2.0:&nbsp HOW-TO - FC3S Turbo Throttle Body Mod

 

Thank you guy's good links and info..
I will read properly when I get in tonight. When you talk about the Right hand dash pot I guess you are referring top the large round brassy body that sits at the lower rear of the throttle body as it sits on the car? It looks like a vacuum body of some sort but without a vacuum pipe to it? What does that do? Looks like some kind of idle adjustment?

Thanks again.
Lee

 

Yep that's the one, this prevents the throttle from snapping completely shut straight away, it helps with emissions on deceleration.

By dampening the closing of the throttle it helps prevents stalling when you snap the throttle shut etc. it is easy to remove or re install so see what its like with and without it.

 

Cheers for all the info guy's. Something to crack on with at the weekend!

 

Been looking at this today. First of all there is a water inlet and outlet stub on the throttle body. One is part of the double throttle system it looks like. Do you just bypass this and have no water to the throttle body once all the emissions bits and idle control are removed? If so do you loop the water pipe from the top rear of the engine to the top of the waterpump housing at the front? Looks like where the route would run if not going through the throttle body?
Also I guess I am going to need a new gasket for the throttle body to plenum as it seems pretty stuck on? Will anything other than 20B fit and do they metal did I read somewhere instead of paper?

Thank you
Lee

 

Yes you will not have any water pipes running to the throttle any more once completed, just follow where the to lines go and link them up....or you can just blank them off at the engine to save running hoses etc.

You don't need a metal gasket as both mating surfaces are aluminium, paper gasket will do.
rather than buying a new one - if the original gasket is intact just place a small amount of master gasket to both sides and bolt it back up.

 

Thanks. I was not sure if it was better to keep that small water pipe to help get airlocks out of the water system when filling it? I probably will to be safe.

 

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