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Discussion Starter · #1 ·
I'm going to buy a spare throttle body for my X16XE, which will later be installed with a mantzel-style inlet.
How can I modify the throttle body?
I read that Courtenay sells modified ones for the X16XE too, but what do they do? Do they simply reduce the thickness of the part that helds the throttle valve? Do they also change screws to smaller ones or even to rivets which would reduce less the flow?
I wrote them an e-mail about 10 days ago but they never replied :rolleyes:

This is the body I'm going to buy, I thought I could enlarge it a bit with a CNC at work and use a bigger throttle valve but I realized it's not possible as the thickness of the body from one side is too small to enlarge it (as you can see in the first photo).





Did anybody modify the original one instead of going for throttle bodies? I don't want to go on that route as it's much costly and I already got the mantzel-style inlet for a good price
 

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Have u thought about buying a throttle body off a larger vaux engine? Might be easier starting with a larger one than trying to enlarge the orginal.
 

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Discussion Starter · #3 ·
I have thought about it, thought I don't know which I could take...

I know the C25XE has got a 64mm one, which I think would be quite big for a 1.6 engine. And also, I don't know if that TPS gives the same throttle opening read as the X16XE TPS.
Adapting the C20XE throttle body to the X16XE would be quite difficult for the egg shape, and here again I don't know how to do with the TPS reading...
I wonder which size is the throttle body on 1.8 cavaliers, if it's bigger than the X16XE one. I asked to the Opel car seller and they didn't know (maybe better to say they didn't want to search for info).
 

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erg

i AM TRYING TO DO THE SOME THING WITH MINE,IN A THREAD I VE READ THAT IT WILL FIT FROM 2.0 ECO????????
 

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Isn't the X16XE throttle body a 63mm opening anyway?
 

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Discussion Starter · #7 · (Edited)
I don't know the dimensions...if it's 63mm and the 2.5V6 is just 64mm, I guess it's a bit strange as the size of the two engines is very different :confused:

I've just emailed Courtenay again, to see if they can explain what their modify consists of. Just to know what I could do...
 

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Discussion Starter · #9 ·
the guys from Courtenay just replied to me:

"We enlarge the throttle body to the maximum we can and fit a lower profile spindle and enlarged buttery. We do not give out the dimensions that we machine to to prevent people from copying our work. The pictures of the throttle bodies on our website are example pictures of some of the throttle bodies we rework. If you want us to rework the TB then ship it to us and we will carry out the work."

Reasonable answer, I didn't expect they would tell me the exact size...but hope is always the last to die :)
I think the gains from the work comes more from reducing the spindle rather than reboring the body, as there's very little thickness to play with.

Did anybody work on the standard throttle body or sent it to Courtenay? Any further info/photo is appreciated
 

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Before going to throttle bodies I ran a modfied inlet on my X16XE and had some tubing sorted for the K&N and that was 63mm. I've got a throttle body somewhere, I'll measure it if its within easy reach in the garage.
 

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Discussion Starter · #14 ·
a little update...

the body arrived, here are some pics:

not a very clever edge on the intake...



the screws are crazily big too...I knew Vauxhall/Opel is stupid, but I hoped not so much :rolleyes:



after an hour of abrasive paper work, the edge has been smoothed quite well, it will need finishing of course



about the measures: the entrance of the body is really 63mm as said, but the butterfly (the measure of interest...) is ONLY 48mm, and can't be enlarged much as around it there are the water channels inside the body.
So as Courtenay didn't tell me 'till which exact measure the body can be enlarged in the butterfly section, I won't risk cutting the body and see through water channels just for a couple of mm improvement... I'll simply change the screws to flat ones and finish smoothing off the edges of the body profile and of the butterfly support.

If anybody else has got further ideas, they'll be welcomed ;)
 

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When i did the same to my old c14se i enlarged the bore by 5mm.
This was done with a boring machine they use for motorcycles to ensure that the center was the same.Making the butterfly was the easy part,i did this with my lathe.It only needs a litle filling on the sides of the shafts line.I hope i helped.
 

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Discussion Starter · #16 ·
how did you do the filling on the shafts? Did you put new metal on it (welded or in another way)?
Was the bore for the shafts the same diameter of the shaft on the butterfly on the two sides, or did you have to enlarge the side holes in the body? I ask as I didn't remove the butterfly and the shafts from the body yet...
did you have the water channels in the body too?
sorry for the amount of questions, but it's helping for sure :)
 

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The reason for all this is my english.I wanted to say that i used a file (if i am saying that right to reduse the diameter on the butterfly in the same line with the shaft.This had to be done because the butterfly will never be exactly vertical inside the body.When i say reduse i mean only about 0.3mm on each side.Nothing else had to be done to the body only the boring.Nothing happend to the water channels but i didn't use it anyway.I hope it helped.
 
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