Turbo vs NA QD32 inlet manifold design.

[nickmcdonald]

Hi all.

Just doing some boredom induced forum trawling, and ended up reading a few peoples opinions that the inlet manifold off of the naturally aspirated QD32 engines is one of the better inlets Nissan made for a diesel. A google search shows me that the four 'runners' on the NA version curl up and over the top of the engine before merging into the intake tract horizontally right above the rocker cover, whereas the turbo version merges into one almost immediately before the head on the vertical plane. Both air intake pipes appear to split off into the four runners fairly evenly as far as I can tell (both about central to the four runners), with the biggest difference being the overall length of the runners; the NA ones are a lot longer than the factory turbo version.

Whats the story here? Are people having success running the NA manifold on a turbo diesel? Do the longer inlet runners prove beneficial? Just curious is all!

Cheers.

[johnny262]

Yes.

https://www.offroadexpress.kiwi/Forums/ ... 18&t=29601

https://www.offroadexpress.kiwi/Forums/ ... hp?t=45031

From what I gather another common upgrade is fitting an airbox from a 1KZ Surf or 80 series Cruiser.

[nickmcdonald]

I’d read the wax terrano build, but not that 2nd link you shared. Very interesting! It seems that the bd30 exhaust manifold is a nice flowing shape and another ‘off the shelf’ upgrade.

[tweake]

i have my doubt that anyone has actually tested the difference the manifolds themselves make, outside of "seat of the pants".

TD27 shares a lot of the head design from the TD42 which they have tested a huge amount. on those really short runners suit the port style a lot better than long runners. all depends on how close to the td42 port design your td27 is as i would bet there has been a few changes over the years.

i understand the QD32T is a whole different ball game.

[HBfarming]

Ask Gale Banks? Air density kg of cold dry air and good fuel on time in the right quantity is what you need for good power. Burn all the fuel turn it into power not wasted as black smoke!
I fitted one to my QD32 turbo. It has been faultless. Bit of an arse to get to glowplugs but it unbolts in half so its no biggie. I like the pwr steer tank bolted to manifold too.