Another airbox mod?

[diesel dog]

The new owner of my Vectra has just shown me another twist on the airbox mod.

What he's done is removed the corrogated plastic pipe that links the air inlet to the airbox. The induction roar is noticeably louder, much more so than when the usual airbox mod is done. Which leaves me to believe that the air inlet itself is the most restrictive part of the system, but it still acts as a useful 'cold air feed' without the link pipe in place.

Having driven the car myself I can say that there is a definite noticeable difference, unlike the one you get with the usual airbox mod.

Some might say: "What about the high under bonnet temperatures?"

Well it seems that they theoretically equalize to ambient very quickly (within 2 miles) due to the normal effect of outside air entering the usual places when the car is moving forwards. Only at town speeds and during idle are the temperatures likely to affect performance (which doesn't seem to be the case at the moment). Plus you have the original inlet acting as a 'cold (ambient) air feed', which could also be lengthened somewhat towards the airbox to provide a more direct source of cooler air.

It's obviously not recommended for those that are hanging around to start a quarter mile run, but under normal driving there does seem to be a good difference....if you don't mind the extra induction noise that is.

Note: Absolutely 'NO' black smoke at all at any revs with this mod, which is something I could never say about the car when I had it! LOL

P.S. Car currently has K&N fitted and normal airbox mod done.

[iaind84]

This is very beleivable, on the corsa forums one of the best modifiactions youlll find for a standard airbox is to fit a vectra 1.9 cdti intake pipe and link it to the airbiox with the link pipe from the astra. (as corsa ones are teeny) how much would you say the noticeable difference is? as i am new to diesels and these sort of subtle mods seem to make moredifference than they do on petrol engines.

Iain

[diesel dog]

The difference is more noticeable than the standard air box mod. There is no link pipe involved, the air box is breathing directly from the fairly large open area in front of the air box itself, and the original, albeit restrictive, air inlet is used solely as a source of cooler air.

I always had doubts about the positioning and size of the Vectra's intake. Someone I know that has a lot of experience with aerodynamics did say that the positioning of the Vectra's intake (just behind the front edge of the bonnet) and the route that it takes from under the slam panel (a sharp left) could make it liable to the many random effects of air turbulence.

[kenp]

pictures? as i dont understand what have been done

[diesel dog]

pictures? as i dont understand what have been done

Not possible, as I no longer have the car.

It's quite simple really. You pull off the plastic corrogated link pipe that fits in between the air intake duct that's under the slam panel and the airbox. I believe that it comes away easier if you remove the end of the pipe that fits onto the airbox first.

What you are then left with is an airbox that breathes through what looks to be a much bigger (and rounder, which apparently is important) orifice. You also have the original inlet still in place, which directs cooler air down towards the airbox. This can be extended using a shorter substitute for the original link pipe or you can cut down the original link pipe if you're feeling brave enough.

[kenp]

ohhh just fit a VXR airintake.. thats much shorter than the normal.. (thats what i have done on mine..)

but now i understand

[Jezzy]

ohhh just fit a VXR airintake.. thats much shorter than the normal.. (thats what i have done on mine..)

but now i understand

I think he means something different to the "VXR" intake - sounds like he means that you disconnect any intake from the air box, so the airbox isn't supplied directly by the intake but is instead just sucking in air directly, some from within the engine bay.

[mark_647]

Ok, honestly...

Im interested in the air box mod but there seems to be a lot of people that dont think it works or even believe it can damage the eninge. I can fully understand why this mod will make a difference but the only thing that puts me off is that when I did this to my old Vec 2.2 150, it seemed to lose power, was a little flatter and afer using it like that for a while, didnt seem the same car when I put the funnell back in lol

So a silly question, is there any possibility this can damage an engine ?

[hairy31]

so in that case remove airbox.............cut 4 " dia hole with holesaw and fit the silver flexi ducting that can be bought anywhere from front of airdam?........

[diesel dog]

I think he means something different to the "VXR" intake - sounds like he means that you disconnect any intake from the air box, so the airbox isn't supplied directly by the intake but is instead just sucking in air directly, some from within the engine bay.

Correctamundo!

The airbox sucks air directly from within the engine bay, but is also provided with cooler ambient air via means of the, now also disconnected, air intake. Fortunately the airbox is situated away from any particularly high heat sources such as turbos, exhaust manifolds etc. This means that the temperature of the air going into the airbox from within the engine compartment will equalize to pretty much the same as that which is entering the engine bay via the air intake within a mile or so due to normal cooling via the front grills. It should be accepted that when the vehicle is moving slowly or is stationary that under bonnet temperatures will be higher.

A bit of info: http://www.torquecars.com/tuning/induction-kits.php