Air box mods

[threedogs]

Has any one changed the OE steel pipes on the Di motor.
looks like a few gains can be had there as well from upsizing
the pipe diam a tad and possibly wrapping it

[threedogs]

For anyone in the know, the OE intake piping is about say 70mm all the way then reduces to 50mm at the turbo.
Which will be most efficient running 76mm all the way then reducing it to 50mm or
Gradually reduce it from 76mm to 63mm to 50mm,
I will be making it from stainless steel and tig welded, not convoluted like the OE.
Im using a VW passat 76mm Maf housing as the VW uses the same maf as the Patrol.

[mjr350]

Does the actual MAF sensor have to be matched to the inside diameter of the housing to get the correct reading or doesn't it work that way?

[threedogs]

from what i can gather the answer is no
HPD do a billet housing that is claimed 30% bigger
and uses the OE MAF , as I asked Mudski.
A few posts back Mark explained it a bit

EDIT ;; plus i have a snorkle fitted

[SG1]

Hmm, I think it does have to be very similar sized piping, remember your stock maf housing slightly reduces in size where the MAF sit inside the piping to speed up the air flow over the maf sensor, the HPD actually is slightly larger in that same area where the MAF sensor sits in the piping(it is honed out slightly where the MAF sensor sits, allowing more air past the maf sensor and slowing the air going past as well), if anything the HPD maf housing could do with being just a little smaller in that area, it is not 30% bigger BUT allows up to 30% more airflow past the MAF sensor tricking it..

Ideally imo the HPD maf housing could do with only allowing 15%-20% or so more airflow past the maf sensor but if you have a chip it can be used to allow more fuel and get a good air fuel mix going and achieve what your aiming for.

[threedogs]

Going to change in intake pipe first going from 76mm tapered down to 50mm
That alone may increase air flow, and yes I have a DP chip fitted. Then I will
increase the MAF housing if nothing has happened.

[threedogs]

Well most of my intake has arrived , need to go to see a guy about the best [most efficient] way to go.
1. 76mm all the way reduced at the turbo to 50mm
2. 76 again and gradually size it down to 63 then 50mm at the turbo
3. is to run 63mm all the way and reduce at the turbo to 50 mm.
Must admit polished stainless looks awesome , plus most of the t bolt hose clamps
arrived too and some special size silicon hose

[threedogs]

Laser cutter is cutting me an air box lid out of stainless steel
to which Ill tig weld a 76mm stainless elbow, getting there>
In the end Ill have a few combo's to try for the best efficiency
Hopefully it'll all arrive this week

Just found a nice piece of 6mm stainlees in my shed Perfect for a lid.

[threedogs]

can anyone tell me about the catch can line that goes into the intake hose after the MAF.
is this just recycling fumes from the catch can
the other line goes to the rocker cover
Can it be eliminated and use a tee from catch can to rocker?

[Dinger]

Where are you going to send the outlet hose from the catch can?