Is250 Airbox Modification

[Tango]

Decided to clean my engine bay today so had all the covers off. Then decided I'd clean my Blitz air filter. Did that then had a random thought about the OEM 'F' Sport lower air box. .

For the few that don't know, Lexus brought out an intake kit comprising of an extruded aluminium intake tube (replaces the original rubber bellows type), a drop-in free flow air filter, and a replacement lower air box that has an extra open intake hole. The replacement lower box also doesn't have angled ribs in it like the original.

Thing is, I fitted my 'Joe Z' intake and Blitz free flow filter long before the 'F' Sport intake was available, so the only thing left to replicate the OEM lower box was to cut the extra hole......so out with the Dremel and .....

Don't know if it makes a lot of difference to be honest, apart from a bit more intake noise, but I place a little more faith in the Lexus Engineers so I'll try it, but any negative effect and it'll be blanked off pretty smartish.

[matt555]

Quality! and nothing like messing with your pride and joy with the dremmel eh :D

[Tango]

Quality! and nothing like messing with your pride and joy with the dremmel eh :D

Well it's a lot cheaper than buying the 'F' Sport lower box, and achieves the same objective. As I said, I'm placing faith in the Lexus Engineers...they've put that additional intake in for a reason...and not just for the subdued howl it now makes when the revs exceed 3K ...sounds very nice though..

The 'F' Sport version

[TigerFish]

Wouldn't there be a cold feed going to that extra hole on the 'F' Sport box? Seems a bit odd to take hot air from the engine bay which is what you don't want normally.

[Tango]

Wouldn't there be a cold feed going to that extra hole on the 'F' Sport box? Seems a bit odd to take hot air from the engine bay which is what you don't want normally.

Nope, that's it, but in that corner of the engine bay there's cold(er) air entering through both through the grill and from underneath. Perhaps this extra intake was what was needed to take advantage of my Joe Z intake pipe and Blitz filter, as there must be a reason why Lexus only market the three together i.e. 'F' Sport replacement pipe, filter and lower air box.

Anyway, tested it today and the pick-up has definitely improved....then afterwards drove an IS-F and wondered why I bothered messing with it