hdp air box lid

[buddy4.2]

has any one using the HDP air box lid if so has it made a difference in power or on fuel just like to get feed back before getting one. ??

[BigRAWesty]

Any increase of air flow is a good thing.
But weather you need it or not is more the point.
Have you or are you looking at turbo upgrades?

[nissannewby]

If your talking for the zd30/gu style that sits in the front left corner. While there is a very small benefit and it is very small, the actual airbox/filter configuration is the problem.

[BigRAWesty]

What's your thoughts NN on modding the front cylinder gq airbox with q bigger outlet pipe??

[nissannewby]

Remove that one and just use the oval type one on the box on top of the engine.

Or a custom setup 4" all the way to turbo (or to manifold in prep for a turbo ;) )using the likes of a ls1 panel filter.

[BigRAWesty]

Remove that one and just use the oval type one on the box on top of the engine.

Or a custom setup 4" all the way to turbo (or to manifold in prep for a turbo ;) )using the likes of a ls1 panel filter.

Believe it or not, I've been told the small cylinder has more surface area than the large oval one..
I was looking at dumping the small one and bring the snorkel in behind 2nd battery.. Need to design it a little more though..

[BigRAWesty]

Remove that one and just use the oval type one on the box on top of the engine.

Or a custom setup 4" all the way to turbo (or to manifold in prep for a turbo ;) )using the likes of a ls1 panel filter.

And hahaha, that turbo is a pipe dream for me..

[nissannewby]

Believe it or not, I've been told the small cylinder has more surface area than the large oval one..
I was looking at dumping the small one and bring the snorkel in behind 2nd battery.. Need to design it a little more though..


You might be surprised with the surface area part. The oval one can actually filter better due to the design of the airbox over the cylindrical one. Have a look at the space around the outside of the filter to the box wall, ideally you want a minimum of 30mm clearance all the way around. Also have a look at Toyota airbox setups, they are huge with lots of space around the filter.

[BigRAWesty]

You might be surprised with the surface area part. The oval one can actually filter better due to the design of the airbox over the cylindrical one. Have a look at the space around the outside of the filter to the box wall, ideally you want a minimum of 30mm clearance all the way around. Also have a look at Toyota airbox setups, they are huge with lots of space around the filter.

I see where your coming from.. No point in having a filter if air can't get to it..

I was thinking of my design this morning..
Thinking a 7" tube, 4" in and out, like an inline filter with pod filter in it..
Roughly 25mm air space at the narrowest point, but up to 50mm at the widest, plus the middle cone if I go one like that..

[mudski]

Ok. I have the billet lid and hi flow maf housing on my zd30. Now out of the box to say, without changing a thing apart from the two items there was absolutely no difference. Nothing at all. But what I have found now I can raise the boost much, much higher than before.
Pre HPD fitment, I could not achieve no higher than 16 psi. Now, I have gone as far as 25 psi and I still didn't see limp mode. So I'm running now 20 psi and the car goes and tows great.

[nissannewby]

Yeah this is likely to be cos of your high flow maf and a small reduction in velocities due to bigger piping. If you could adapt your maf to a 4" setup all the way from snorkel to turbo then you would certainly see a difference particularly in response and torque.

[mudski]

Yeah this is likely to be cos of your high flow maf and a small reduction in velocities due to bigger piping. If you could adapt your maf to a 4" setup all the way from snorkel to turbo then you would certainly see a difference particularly in response and torque.

Yeah after installing the lid and housing I looked at the piping from there to the turbo. Much smaller in diameter. I actaully drew out and measured up new piping to match the MAF housing all the way to the turbo but time restraints due to work has stalled that idea. Plus having a TD42 in my garage has kinda made me lose a little interest in spending any more time and money on it.
But, if I were to do this I would try to make the housing on the intake side of the turbo bigger too. But that would be a big job in itself...