[Bill1onz]

Morning,

I am looking to purchase a induction hose and possibly an RS style airbox lid. I know that the diesel engines can throw up warning lights when putting certain parts on. What parts do people currently have on and do we know what the Focus likes and doesn't like? Also should this cause a drop in MPG? Is it worth it or should I just leave it as standard?

Thanks in advance!

 

[Radiator]

Pumaspeed induction hose, k+n filter, big mouth scoop, Rs lid and Pumaspeed 1r map. No issues.

 

[Bill1onz]

Surely you are drawing in more hot air from under the bonnet with the RS airbox lid though?

 

[NickFST3]

If the diesel is anything like the petrol version as long as you keep the under bonnet insulation on & the RS lid seals to that any temperature increase is almost un-noticeable. Basically I think the lid just lets a bit more induction noise out. At least that is what Collins told me when they fitted mine!

 

[WayneST-2]

I had a K & N filter in my ST TDCi when I first got it, ran fine with that. I later switched the AirBox Lid to the RS version, still ran fine, just more noise (More of a deep roar noise than the sucking noise that open filters make on a turbo petrol) and also seemed a bit more responsive.
I switched back to a complete standard setup after experiencing issues following a remap, and also got bored of the added noise.
Reading other posts on hear and other forums on the net, the diesel does seem particularly fussy with induction mods, some are fine, others do the limp mode thing the moment anything is changed.

I still have the RS AirBox Lid and K & N Filter if you're interested.