G60 throttle body porting - new update

[JMC 0]

Cheers Flusted, always useful to see ones that have already been done, and for the advice about flap wheels - all I need now is a dremel. Not sure about modifying the boost return section. I'm sure Darren will be back on here later and will be able to add something constructive to that...

 

I'm still trying to take mine apart - got some done last night, but it really is complex. Should be another fun night of figuring it out tonight.

[W3RKD 0]

picture -

[flusted 0]

yeah thats what i was on about 8) as said before ive polished through 2 in that place so be carefull

[JMC 0]

Thanks Darren, I've removed about 3mm there so far, but after what flusted mentioned, don't really want to port through it. Looks like I'll have to go slow and remove some more, but the difficulty I'm finding is the problem of actually getting something in there to do it.

[W3RKD 0]

Its a simple solution... Get a good bead of weld put on the back before porting comences

[JMC 0]

Its a simple solution... Get a good bead of weld put on the back before porting comences

 

That's what I like - definately a good way to be able to remove loads of material. Will have to see if my local shop will do that for me.

[JMC 0]

Even started on the other bit tonight, after I figured out how to take it apart (complex, and going to be fun to put back together). Mmm more sanding and polishing needed.

[flusted 0]

if it helps the part nos for the gaskets are

 

037 133 073 A

037 133 074

[JMC 0]

if it helps the part nos for the gaskets are

 

037 133 073 A

037 133 074

 

Thanks flusted - saves my dealer floundering around for hours trying to find them :lol:

[JMC 0]

Right next bit, before I start on it. Does the section between the 2 butterfly valves even need to be there?? This would make air flow into he smaller valve alot easier, and I can't personally think why it needs to be so high. Was thinking of removing material as outlined by the red line below.

[flusted 0]

yep ditch that bit, heres mine, sorry for poor quality

 

 

backside

 

 

Ive decided to refit the wedge so will se how it drives tommorrow

[JMC 0]

Those are really useful pictures flusted, and don't worry about the quality - I can see where you've taken the material off from it, which is the important thing. I hadn't even thought about doing the rear face :shock: . Looks as though I've got loads more still to remove.

[ninoG60 0]

might have a go myself, looks like some gains could be had. :D

[flusted 0]

i was lucky doing the rear, i cut the top off the inlet mnanifold and flowed that, then bolted the tb to it and marked out the tb line in the inlet manifold if that makes sense?

Basically port matched the tb to the inlet.

 

 

It would be so much easier if your were using flap wheels, that bit you wana cut out the half moon on the divider, that shape just appeared on mine whilst i was using the flap wheel

 

I even read somewhere that some people using a different injector in number 4 cylinder as airflow to it is so restricted, they dont want that cylinder running too rich :shock:

Think that air as soon as its gone through your tb, has to take a sharp right angle to go down number 4 port.

[JMC 0]

That manifold looks good - never seen inside one of those :lol:

 

Done a bit more to my throttle body tonight - getting there slowly.

[flusted 0]

heres a 16v 1 i did a while ago

 

[_leon_ 0]

are the gains from this significant?

[flusted 0]

it can only help 8)

[W3RKD 0]

it can only help 8)

 

Not allways im afraid. there is a huge differance between Airspeed vs Airflow. We cut and shut an inlet very much like yours in the early days and actually lost power (noticably when driven too) We then ran mk1 golf Inlets and made 6-10 lbs of torque more at a set point.

 

The injector thing is total BOLLOX due to the injectors being batch fired, dont believe everything you read on the internet.

[JMC 0]

it can only help 8)

 

Not allways im afraid. there is a huge differance between Airspeed vs Airflow. We cut and shut an inlet very much like yours in the early days and actually lost power (noticably when driven too) We then ran mk1 golf Inlets and made 6-10 lbs of torque more at a set point.

 

So does this go back to my question earlier....

 

"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?"

 

Like flowing a head, there's no point just making it bigger as the gas slows down so much. Is it all about about a balance of generating efficient smooth gas flow when it is needed??

[JMC 0]

Ok folks, here's an update of where I've got it so far. Just been polishing with the coarsest grade compound I've got - 2 more to go. Quite happy with how it's coming, but welcome any comments :D :D Going to take the other section to my local mechanic tomorrow to see if he'll put a bead of weld on to help with removing more material.

[flusted 0]

looking good, although it looks like youve shaped it as if the air is hitting it straight on, which it doesnt as the samller butterfly is off set.

try shaping the divider slightly to the left as you look at it if that makes sense

[yellowG 0]

i purchased a spare G60 throttle body (as car is my daily driver) and ported the inlet to as far as i dared! this is a picture of it against standard inlet, its improved throttle response....

[JMC 0]

I've had some ally welding done on the 1st part of the thrttle body now, and have sanded that back further - should have addressed the issues outlined before.

 

Only slight problem is that where there are bubbles in the welding I'm now left with lots of little holes - does anyone know if JB Weld or some other chemical metal is suitable for filling these as I want to keep it as smooth as possible??

[flusted 0]

i smeared a small ammount of chemical metal in mine, doubt it will make much difference tbh