Based on observations of the IAT at the MAF the factory system reads very close to ambient temp at highway speeds after a few minutes. Stop in town for a few and of course things heat up. There was an aussie company that has since gone out of business that was making a Thor intake manifold, they claimed the throttle body section of the factory intake was restrictive at high rpms but I have seen no data. Its a little like re-arranging the deck chairs on the Titanic, tiny changes on this small and engine do not turn in to big noticable improvements.

 

I could've written every word myself.

 

I checked the IATs on my original setup once, but truthfully I do not remember the results. That's been years ago now.

That said, there was a bit of a difference in how she ran. Nothing night and day, but it gave the truck a little bump despite the bump in temperature.

I do believe the increase in temp was almost entirely at idle and very low speed, that once you got moving the temps came back down to nearly the same as the factory temps due to the volume of airflow thrilough the engine bay.

 

Temperature has increased by around 10 degrees but is much cooler when moving at speed. Engine runs and sounds better. Idling temps are much higher unfortunately. Might go back to stock for the summer months.

 

I agree, have a very similar set up. I do think it drives better, plus sounds better. I did observe the intake temps before and after and there was nearly no difference in the data. I agree it may be counter intuitive, but the filter is nearly the same place as the original. As opposed to pulling purely from the outside purely.

Again to each his own. I see no quantifiable downside.

 

If I was you I would thermal wrap that tube. You're going to be getting higher temp intake air due to heat soak from a metal tube. I've used exhaust thermal wrap and even the reflective thermal tape and wrap for home HVAC systems and has drastically reduced incoming air temps. Also make sure when you treat your filter aka oil it. Make sure the oil has dried prior to running or you will get maf fouling and cause your fuel consumption to sky rocket or mil code. I know wrapping doesn't always look as pretty at the tube but functionality is the key here not looks.

 

I've had this thread bookmarked and have been considering upgrading my intake for a while.

While traveling I may have come across an idea to improve upon the intake modification above. I'm in Kenya at the moment and have seen a few vehicles on the road that we don't have in the US, the one that peaked my interest is the Nissan Patrol GU Diesel, these trucks have an offset hood scoop to feed cool air to their intercooler (here is a link to an example).

It might be possible to use a hood scoop to feed air into a airbox with thermal insulation and an after market filter fitted between the top of the engine the power steering fluid reservoir and the ABS module. In theory, this would enhance airflow and decrease air temp at the intake.

This idea still needs a bit of refinement and I'll do a bit of measuring once I'm back stateside.

Has anyone seen something like this fitted to a Disco before?

 

I got rid of this setup a while back. As many mentioned the air temps were way too high for my liking.