ITB trumpets vs Air cleaners

I am working on an air filtration system for my V8 ITB setup. Looking at K & N, it seems there are different types of filters. Some incorporate the trumpet with the filter on top, others bolt to the top of the ITB and I don't know if they then add a trumpet or delete it completely.

Does anyone have any experience with this? If I design my own mounts, should I run the trumpets inside the filter or should they be left off?

I prefer ITG filters and the like with the mount plate sandwiched between the throttle and the trumpet. They have a variety of their 'JC' blank dimensions as well as filter heights.

You should always use trumpert or, at a minimum, bell-mouths.

Normal practice is to sandwich the plate between the trumpet and the body - you may note some will say "undrilled", which is for the customer to drill the plate to match their specific bore' and screw' diameters and positions.

Some will also offer offset, or deeper plates, so if you have long trumpets they're great for clearance. If you have the clearance you could use them with/instead of taller filters.

One thing to be aware of is that the top plate, if used, can give a reflection signal back into the intake, and the closer it is the greater the affect. For this reason I'd suggest the tuning be done with it/them in place, just in case there's a weird pressure wave situation that affects the fueling and/or ignition.

Different filters also have differing efficiencies - the actual filtration and resistance to flow - and so usually the greater the filter area available the better.

Something else to consider it whether you want to incorporate the filter in an air-box, with a cold and/or air ram feed - this can make a significant difference in some engine compartments due to the high ambient temperatures in the engine compartment. Some filter manufacturers offer air boxes, they can be found in the aftermarket for some applications, or you can fabricate your own.

Hi, ITG filters with a blank base waterjet cut to suit, as described above, picture attached. In this case hung of the underside of the return lip on the trumpets to clear the fuel rails. Cheers, Andrew