Ok, many V6 owners have common issues with the original convoluted rubber tube that connects to the throttle body.. Over time this starts to split and deteriorate. your Maf ends up out of whack trying to balance the airflow with what it thinks is correct but does not correlate with what the lambda sensor indicates, thus running lean.
This in turn can cause idlle problems, throttle body getting dirtier and lack of performance
A lot of V6 owners turn to quick fixes like duct tape but that is like patching the Titanic really.
You can also replace it with OE but costs a fortune from the main dealers as they sell it with the entire plastic helmholtz tube all the way down to the maf
So what's the cure?
Simple... Make it stronger than OE and while you are at it, give the engine bay a pep up with bling and a couple of extra horses to boot.
Something like this kit!
There are many ways to do this but usually involves Silicone bends, alloy pipe work and either silicone T-pieces or small breather filters..
The breather filter effectively eliminates the need to have a breather pipe attached but has its pit falls:
1. its illegal. you are pumping unmetered fumes into the atmosphere that should be recirculated, YOU WILL FAIL YOUR MOT, trust me on this... I'm a Vosa MOT inspector
2. Tiny little oil droplets from the breather pipes lubricate your throttle body to work properly and prevent it from sticking... cutting that lubrication off that is supposed to be there is never a good thing.
Now we get to T-pieces be it alloy or silicon, that's better.... at least you can connect the breather pipe straight to the induction system.... Right?
Well.... there is a slight problem with that too (yes I have checked this out thoroughly)
1, The original convoluted rubber pipe may have a larger bore going to it but if we actually take the time to look inside or disect it you will find that the exit hole into the convoluted pipe is only 3mm! I think the suppliers who sell these will contest it but there is a very good reason for the original 3mm hole
The T-pieces you buy are 25mm
Is that a bad thing?
Well yeah it can be
Those oil droplets nowhave a nice big smooth uninterupted bore to start running down your pipe work all the way to your vunerable MAF sensor when on idle, they drop on it and it ends up getting coated with dirt over time and then we end up seeing threads complaining about Maf issues and everyone jumps on the bandwaggon and blames the aftermarket filter they installed.... A maf can get dirty from either side up or down... remember that!
That tiny lip provided by having a 3mm hole is enough to build up a pool of droplets when idling and then has the suction from normal throttle situations to dissapate it safely as it gets sucked through the throttle body when you pull away
Now we have got that little lot out the way, we can start to plan a replacement that follows the design points of the original pipes.
Do we need to follow the exact route?
No, but certain rules needs to be met.
The MAF should be a minimum of 30 cm (12") from the throttle body to create the correct vortex speed of air flow, too close and you get buffeting.
Size of bore! 76mm
It would be ideal for petrol heads to fit the largest induction pipe they could right?
No.... The limitations of laminar flow and dictation of a 76mm throttle body and 76mm Maf body say its best to stick to the same size of 76mm all the way through, too big and you end up slowing the flow down, too small and you limit the flow
The bends of the entire run... Most owners of modified induction systems on the V6 will loosly follow the correct bends, Nothing wrong with that whatsoever!
However... Try buying a silicon tube that has a 95 degree (original is not 90 degrees btw) followed by a 35 degree kink (not 45 degrees) then down to the maf (you guessed it, not 90 degrees) but 85 degrees to take into account for the drop in height from throttle body to, filter box top!
I double checked, sad... I know
Besides that , if you want to release any horses, the longer you make it, the less you get in return... But... Bear in mind the minimum 30cm distance overall though.
You can get away with a 90 degree bend from the throttle body and followed by a 75 degree bend to allow for the height drop followed by a silicon connector to the maf, thus saving even more money
So now how the hell do we attach all this to the breather pipe?
Well you won't believe this but I found the easiest solution ever.... A 14mm drilled hole in the alloy pipe, filed all the swarf away of course and wait for it...... A standard tyre valve with the valve core removed
It has a sealing lip that moulds to the shape of the hole in the pipe.. You push it through from the inside and give it a tug until it the first shoulders of the lip come through, give it a slight twist and it's an air tight seal
Guess what the internal diameter is? 3mm
Now connect with a rubber hose (12.7mm) As it slips over the original plastic breather connector (just with a push) and also fits the bore of the tyre valve nicely... Simply clamp up properly with the correct size jubilee clips
ONE THING I WILL IMPART THAT IS IMPORTANT!
Always clean the inside of your new pipe work before fitting
They are full of grime that won't help and if you cut or drill, swarf will make short work of valves and throttle butterfly!
PICS to prove it:
I did this all in the back yard instead of the workshop, just to show that with basic tools, you can end up with a professional install!
It fits perfectly
Here's one last tip... Use the opportunity to clean your throttle body? Maf and do a throttle/ECU reset to gain the benefits
So what improvements:
With the Helmholtz resonators removed and the shorter, smoother run it has a deeper sound that compliments the v6, the throttle feels slightly more responsive and less of a need to put your foot further down when on inclines or pulling away... Maybe just me but seems to have more lower down usable torque and more rapid proggression towards the top end of the rev range...
My next project is:
I currently run an Apiro Torque dual cone filter inside the original air filter box (lid removed of course)... This keeps it away from the elements, prevents heat soak as and reduces the induction roar as standard... The kit I bought has loads of spare tubes and connectors so I am going to remove the standard v6 outer airbox pipe and make my own cold air channel to the airbox