making your own intake

[webby888]

I do Metal fabrication as a job and at the moment i have a K+N intake on my car, to me it doesnt look too hard to copy and make my own.

Is there anything i should be aware of or look out for? Anyone done this before?

I can source all the materials through work along with the machining, welding etc so im thinking why not give it a go??

[cupra_k1]

Providing you keep the size/area of the MAF housing the same as standard there shouldn't be a problem. The standard MAF housing is ellipse shaped but i believe all the aftermarket intakes use a round tube instead, purely due to cost and ease of fabrication. From memory, the diameter of a round MAF housing should be 66.55mm for correct MAF scaling. This will allow the MAF sensor to get a 'true' airflow reading keeping the fuel trims within limit.

2 3/4" 16SWG Aluminium tube should be perfect. A larger diameter tube can be used before the MAF sensor though improve airflow.

[tony_danza]

I didn't make this, but it performed fantastically on my car.

The main thing is understanding flow dynamics, anything that disturbs the flow is bad. So you want smooth, mandrel bends and as few joints as possible. I'd recommend an ITG filter, rather than the K&N I used in this pic, it wasn't as good. If you look carefully, there's also a cold air feed coming from an open grille to the bottom of the airbox.

[skiddusmarkus]

Ideally you want 2 x 45 degree bends before the turbo, looks like you'd have to relocate the battery to do that though.Not a golf but something I made up for my Pulsar.No fabrication skills needed, just an angle grinder, bit of sand paper and time.



If you move your battery, it really opens up what size filter you can fit in and doing it yourself bings the cost right down.This cost me about  £70 to make just buying the bits off ebay, using an online K&N catalgogue to find the biggest filter I could fit into the space I had.
Ignore the i/c piping, it was a mockup for a blowthrough maf setup which is now a one peice stainless pipe getting rid of all the joints and plastic z32 maf which aren't keen on positive pressure.

[DJM]

If i remember correctly from when i was looking at doing this, you could buy a after market maf housing. Then just do custom pipework.

I personally just waited and got a K&N kit off for sale section for £130. These come up and the neuspeed ones for around that price. May be a cheaper option than the ITG n forge kits

[skiddusmarkus]

Assuming there are no breathers/vacuum pipes attached to it, you could make a brand new setup like the one in the picture with gold on it for £77ish just from bits off ebay.2 x 90 degree bends at £15 each, a silicone joiner for a fiver, 2 x jubilee clips and the filter would be £40 for a k&n.If any extra bits needed welding on then add £20-30 on top.

[jimk04]

Its just the bit where the MAF attaches to - really needs a bit machining to do it nicely.

But yeah ebay special bends here we come!

[jimk04]

Just had the airbox off and measured the MAF housing.

Pretty much confirms Cupra K1s reply above about diameters of round pipe.

I made sure to measure the inner ellipse where the airflows only, not the outer bit where the rubber o-ring is.

I come up with 3185mm2 - which equates to a 63.5mm/2.5" inner diameter (which gives 3166mm2 - near enough)

So assuming about 1mm wall thickness you have approx 65.5mm O/D (Cupra mentioned 66.55)

Confirmation of known info I guess but its raining outside and I'm bored.

[RedRobin]

Confirmation of known info I guess but its raining outside and I'm bored.

....I'd have to be much more than bored to even want to think about making my own intake.

Unless you are an engineering professional who is well versed in exactly what happens in a modern complex engine, I would leave well alone!

[PDT]

I had some TFSi intakes made up by a fabrication company, they worked perfectly well but too noisy due to the thin walled aluminium we used to make them with.

As long as you use good quality materials and get the maf housing correct its simply a filter on a tube.

[jimk04]

^^^Yip! - Air goes in, thats all it does. Keep MAF scaling and jobs a good 'un.

[Shabba168]

It's getting a nice finish on the pipe. Been looking for a while on getting one I like the K&N intake crackle black finish