G60 throttle body porting - new update

[JMC 0]

As I've bought a spare G60 throttle body to port I was wanting to find out how people have taken these things apart to do the work. Especially thinking about separating the 2 halves, does all the micro switchgear, etc and butterfly vlaves have to come off as I don't want to get metal dust/swarf in to where it can cause any damage?? Any advice would be great, thanks...

[flusted 0]

i didnt bother removing the switches but it should be easy.

Undo the boost return linkage and the outer half is just held onto tb with 2 torq screws.#

I used flap wheels to do mine then finished with wet n dry

[ninoG60 0]

did mine on a milling machine and then used flap wheel and polishing wheels to do mine, flusted hows yours?

[JMC 0]

Cheers guys. Is it better to enlarge the entry to the small butterfly valve or the large one, or both?? Seen pictures of different variations on a theme with that.

[flusted 0]

heres 1 i did

 

[JMC 0]

Aha, so it looks asthough you took some off both side there, and took it down to a knife edge. Have you done anything with the butterfly vlaves themselves??

[g164rge 0]

What difference doing this would it make to the engine?

[JMC 0]

Basically it helps the flow of gas by removing obstructions, and therefore has the potential to improve power. I say potential as it really only works when everything has been flowed from what I can deduce. As I've had the inlet manifold and charger flowed and head work done, it seemed the next obvious thing for me to try, especially if I can do it myself.

[g164rge 0]

Basically it helps the flow of gas by removing obstructions, and therefore has the potential to improve power. I say potential as it really only works when everything has been flowed from what I can deduce. As I've had the inlet manifold and charger flowed and head work done, it seemed the next obvious thing for me to try, especially if I can do it myself.

:thumbleft:

[Toad 0]

The throttle body is the smallest part of the inlet system, and causes the biggest obstruction, the idea behind porting and polishing it is that airflow through the body is maximised, so that at full throttle the maximum air can flow through it, and during throttle openings the air flow can change speed quicker, improving throttle response.

 

The maximum airflow is governed by the size of the chokes ultimately, but smoothing the path to these and after these will be of benefit.

 

I've just picked up a throttlebody from mr beige which he has been ported and polished for my 16v, although no other work has been done, I would like to thing that it will make a difference.

 

I'm spending my evenings with a tin of brasso trying to achieve a mirror finish at the moment.

[flusted 0]

I also dewedged mine but it makes throttle very jerky so beware.

I just hacked as much as i could out of everywhere and matched the 2 halfs together.

Also opened upo the back of the throttlebody and match ported it to the inlet manifold

[JMC 0]

I'd heard that dewedging them could do that, so will probably avoid that then and stick to just porting and flowing the body of it. I can feel the weekend job coming along....

[flusted 0]

i find it is bearable with no wedge but i just look at the flow increase it must gain without it and decide to put up with the jerk.

theres quite a sharp edge on the elbow that can be smoothed out but be carefull as ive poted through 2 of them elbows by accident :shock:

[JMC 0]

I thought that looked like a sharp edge in there. Good watch out about porting through it though - sounds like the type of thing I would do :lol:

[JMC 0]

Ok, I've started porting mine - attached, and yes this is just the first stage of porting hence it's still rough.

 

Question for the experts - is the idea with this 1st part of the of the throttle body to make the diamater of the hole bigger or just smooth off the flat surfaces?? And why??

[flusted 0]

smoothing that entry should be fine, just some people find it easier to bore it out.

 

heres the difference

 

[JMC 0]

smoothing that entry should be fine, just some people find it easier to bore it out.

 

heres the difference

 

 

Wow, that is a huge difference :shock: . Puts my filing into context. Now, if only I had access to a machine shop

:?

 

So is porting this section like porting a manifold - a trade off between torque and horsepower?? Just been thinking about it, and surely there is a trade off between fast gas flow (through a smaller but flowed and flat surfaces removed hole) and more but slower gas when it is bored out. Or have I done my usual and gone off on a complete tangent :lol:

[JMC 0]

Right, done a bit more and started removing some of the rough marks from the file. Also taken some material out from within where there was a sharp edge (Image 2, and I presume that was where you were refering to flusted?). Came back in with hands looking like hey were from the Tin Man in the Wizard of Oz after doing this :lol:

 

Ok folks, I still want to do more smoothing of it, but does it need to be really mirror smooth at the end??

[flusted 0]

yeah thats looking good, still try and round off that edge on the second pic.

[Riley 0]

Here's some pics of mine that i did a few years ago or sommet.

 

I decided to venturi the entry...Definately gave a more snappy throttle response.Also ported and knife edged/polished.

 

[JMC 0]

Here's some pics of mine that i did a few years ago or sommet.

 

I decided to venturi the entry...Definately gave a more snappy throttle response.Also ported and knife edged/polished.

 

Wow that looks really good. I've been finding loads of imperfections in the casting of mine, so looks like I'm going to have plenty of polishing to do. Started on the other section as well, and have decided to take some off the entry both valves. Very rough at the moment, and am in the process of taking it all apart for easier access (man that thing is complex :? ). Cheers for the advice too flusted, will have another go at it.

[flusted 0]

i tryed to angle the divider towards the entry if that makes sense,as the air wont hit the small butterfly straight on because its off set to the big butterfly

 

I gota take mine off today so il take some more/better pics

[W3RKD 0]

you havent yet touched the biggest restriction in the throttle body.. il add some text to your pic 2 later so you can see where to remove the material.

[JMC 0]

you havent yet touched the biggest restriction in the throttle body.. il add some text to your pic 2 later so you can see where to remove the material.

 

Cheers Darren, get the feeling I'm going to need different tools though, as I've been doing this with a file and wet and dry so far, and am running ut of bits I can easily get at :lol:

[flusted 0]

flap wheels are your friends 8) my throttlebody is off so will add pics later.

 

Ive just put the wedge back in to see what difference it makes.

Also i adjusted the boost return linkage so it shuts earlier but unsure if this is a good idea?