No, I'm not a boy racer! 🙂

I've got a camper van with a humongous airbox located to one side of the engine bay, by swapping this with a 'performance' air filter I can free up a large gap which will be big enough to install a big leisure battery, probably squeeze in a 200A/hr battery into the gap.

First concern is I have an air sensor tapped into the under side of the airbox, to fit the air filter I need to chop the ducting at a mid point, can I just fit the sensor closer to the engine without messing things up?

Second, I wanted to maintain the air intake at the front of the van as the engine gets quite hot before the cooling fan kicks in when towing, and every bit counts on the hills. I'm usually in 3rd gear when pulling the trailer up anything more than a slight incline. So that means getting an 'induction kit', as far as I can see, that just involves the filter being inside its own airbox and a bit of duct to draw fresh air in. But all the ebay sellers are going on about throaty induction roar…the engine roars enough as it is 🙂 Should I be concerned or will it be hardly noticeable?!

At least I've found a plain black one without any anodised bits of bling on it…

Depends on teh sensor you're shifting. If it's the temp sensor and it's not turbocharged – yes, should cause no problems to move it anywhere in the intake stream, providing it's not unusually hot. If it's the air-flow measurement then you might need to be a bit more careful to keep it in a clean flow of air, not too close to bends or restrictions.

You're bound to get a slightly more deep engine note, but with an induction kit it will be minimal, open filter is nice and loud but kits tend to be much more quiet, though not as quiet as standard. But again it tends to depend on exact lengths. Remember that stock intake setups tend to be accoustically tuned to reduce resonance and smooth the intake pulses, depending on what car/engine/age etc you could actually degrade performance, but I suspect on a camper you'll be just fine.

Its a 2004 Iveco Daily, 2.3L 120bhp Turbocharged. The sensor sits outside the air box and just has a pinhole to sample the filtered air, nothing inside the duct.

I only started getting concerned about noise when I saw a kit with a 'turbo fan' installed in the filter housing?!! It looks as though it does nothing more than freewheel, but I suspect it has some noise element to it…

The two kits I'm looking at are identical except one has a silver aluminium induction hose, (will reflect the heat and looks like it is smoother and will restrict the airflow less) and the other has a black plastic hose (less bling, presumably more flexible).

http://cgi.ebay.co.uk/Apiro-Forza-Universal-Induction-Air-FILTER-KIT-BLACK_W0QQitemZ350302882699QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item518fadcb8b#ht_2206wt_1161

http://cgi.ebay.co.uk/APIRO-FORZA-BLACK-UNIVERSAL-INDUCTION-KIT-RAM-AIR-NEW_W0QQitemZ380190886265QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item5885248979#ht_3024wt_1161

Its unlikely that changing the intake will reduce performance, the flow rate compared to the exhaust is minimal, better exhaust can add 10%-20% to the power over standard quite easily, intakes are more like 4-5%. The important bit is between the carb/throttle body and the inlet valve which runs at a vacumn and therefore is very sensitive to pressure drop. On an injection engine all your doing is effectively opening the throttle slightly more. On a carberetur engine you may need to set it slightly richer.

As for noise, I wouldn't worry too much, its unlikely to be intrusively loud.

Also, is it likely to have much of a negative impact on my impressive 21.5mpg? That is towing a very large and boxy 2.5t horsebox…does about 23mpg when driving solo 🙄

tinas – flow rate changes on the intake can be pretty big, I've known 200hp standard cars drop 10hp with a cheapo intake, even more when the owner thinks that a piece of tube roughly placed near the filter and extending out under the wing will "feed cold air". There is a reason the intake is carefully tuned at the factory. But that's on performance cars I suppose. Dont forget cold air has much higher frictional losses than hot exhaust, but the same theories apply.

Sensor – difficult to tell at this stage but from the pinhole description it sounds like a pressure sensor, but I can't see any valid reason to have a pressure sensor at that point (unless it has clever electronics to tell you when the filter is blocked on this van, or the filter comes after the turbo but before the engine (unlikely)?). Assuming you can mount it back in the same "configuration" (i.e. same approximate location in the intake, engine side of filter but before turbo for example) you shouldn't see any trouble.

Either of those two units will do the job assuming they're long enough to get the ambient end into air in front of the radiator. Bear in mind that you will almost undoubtedly be letting more junk through than you were with the stock filter, but you may well be willing to risk that. Without seeing actual photos of the sensor and intake setup I'd struggle to advise fully as I've never worked on that engine.

Assuming your engine is electronically controlled and not carb'd, it wont negatively affect your economy unless you're more tempted to hoof it. All you're doing is reducing the pumping losses on the intake. The engine management will attempt to maintain the same fueling as before.

Thanks, sensor is just after filter and before turbo. If I relocate it, it will be much closer to the turbo, about 20cms before the 76mm duct starts to reduce down to what looks like a 30mm duct entering the centre of the turbo. I think I remember seeing a 'blocked/replace air filter' lamp that illuminates on the dash, if thats it, is it likely the sensor also affects the fuelling of the engine? I might do some digging in the workshop manual, if its just a lamp and doesn't affect the engine I could save myself a job and just disconnect it and stick a resistor in to keep the lamp off 🙂

Sounds like it just uses a differential pressure sensor setup on the either side of the filter, that would tell it whether there was excessive pressure drop across the filter. Providing it stays in the same place relative to the filter you'll be fine. I suspect it has nothing whatsoever to do with your fueling, that'll be controlled by a manifold-mounted pressure sensor which keeps track of turbo pressure etc and is taken between the throttle and the head.

Thanks that's good to know. There is no sensor on the intake side of the filter, but there is an 'air filter clogged' warning lamp on the dash, so it must just light up when the vacuum reaches a certain limit.

I ran an aftermarket air filter on my 2.5 v6 Alfa and it destroyed air mass meters every 12 months and 2 days (always within a week of the warranty running out).

The air mass meters is very sensitive and easily damaged.

Well its not an Alfa, but it is Italian so maybe I should still be concerned 😉

We also have another Italian, a Fiat Punto, and that has been teasing me with headgasket type symptons for the last couple of weeks, thankfully it was caused by something that is easily fixed 🙂