The definitive "What Air Filter?" discussion thread

[luke1 10]

Thinking of getting one of these for my 1.8 16v, along with adding a similar cold air intake mod to Ralphead.

 

Who can advise?

 

Cheers.

 

[ATTACH=CONFIG]60577[/ATTACH]

[mookie 0]

Thought I'd add my 2p about my VR6.

 

I've just ditched a no-brand cone (previous owner) for a standard box. The cone was fairly civilised round the houses, quiet, unassuming. Sounded like a race car when given some beans, and at high revs doing a decent speed genuinely sounded like something going around a racing circuit - raw, very loud, but very nice in my opinion.

 

I put a completely standard airbox on tonight. Immediately the car felt so much smoother to drive, especially after driving at motorway speeds and back to 30. I could feel the difference straight away just driving out around the streets... which to be fair I did not think was going to happen. I haven't noticed much change to pulling at speed, or rapid acceleration other than added smoothness - doesn't feel any sharper or more responsive but does feel a lot more refined and less raw power. The noise difference is huge however. In it's first incarnation, the OEM airbox seemed almost silent in comparison, and I was very disappointed in the standard VR6 sound compared with the mental race car roar it offered beforehand. Even flooring it and letting the rev's climb at high speed, it sounded a bit tame and ordinary. However, I whipped it out and removed the front tube insert (the intake opening must be 100% bigger without it) and tried again. This time the sound is perfect and very different. No change in performance that I can feel, but the noise is sublime. Much deeper, more throaty, and lacks the top end scream it had with the cone. It's a much warmer, feel-it-in-your-guts kind of noise. Very quiet still on normal 30mph routes, but floor it and the sound builds from nothing to a really loud warbley-wail that never sounds annoying or ASBO-y. Like a mini-supercar rather than a mini-Nascar. Very, very pleased. Smoothness and an even better noise.

[DriverVR6 11]

Standard airbox is the way to go. The intake you have removed has a venturi effect that increases the airspeed, although I do not know how much of an effect it actually has.

Induction kits (regardless of which one you go for although some are better than others) require a huge cold air intake to give the "ram effect" to see any increase in power, and it needs to be a closed system to generate the pressure. And the Corrado just does not have the underbonnet space to locate that size of air feed, unless you heavily modify the front of the car.

[Redfox 10]

Mookie,

I experienced exactly the same on my G60. Out went the K&N and the v8 roar. In went the paperfilter and snorkel. Totally quiet and boring (well, not totally, but in comparison). Out came the snorkel, and voila, a great subtle sound and perfect filtration. No more oilcrap in the charger that sands it down in no time. Never again I'll have a socalled sportsfilter from whatever brand. I've had Sparco and K&N. Always kept them clean and oiled them very lightly with the K&N set. Never again. Happy soloution. And as DriverVR6 says, no heat from engine to be sucked in and make less horsepower etc.

 

Cheers,

Redfox.

[DSLDave 10]

Thought I'd add my 2p about my VR6.

...........However, I whipped it out and removed the front tube insert (the intake opening must be 100% bigger without it) and tried again.........

 

Hey Mookie, that piece you took out - is it right at the inlet to the airbox directly behind the headlight? Do you still have it that way, and do you still think it was a good idea to take it out? I've a new VR6 a couple of months now, and thinking of doing the same, based on reading your post.

[Redfox 10]

Been thinking a bit about it, and I think that standard filter is the way to go, together with the standard airbox. But removal of the snorkel. The thing is that the snorkel is probably there for two reasons. First, is because of induction noise that must be supressed to become legal on all markets it should be sold on.

On my G60 I removed the K&N and inserted a standard paper filter. Plus I removed the snorkel. The standard length on the snorkel is really really long, and the air have to pass all the way through the long snorkel, and then turn 180 degrees inside the airbox, goinf forward towards the headlight, and then reverse at the front of the box or somewhere around there, and then into filter, through that and then into the rest of the system. That can hardly be good for performance. So off went the snorkel. I did not do a rolling road test before and aft. this, so I would not know for a fact what it does, but my engine is otherwise completely standars, and I get 177 Bhp and 228 Nm on my G60 (1991 P-head engine). After I installed a 2½" system from cat back, but that is going to be cut up completely and changed, also with a free flowing cat and samt size 2½ inch tube, with no small decreases in diameter, like the standard cat has, on a flow bench to get max power. But only in the Spring, now everything is covered in ½ m. snow. I report bach on my findings when time comes.

Secondly, the venturi effect that Driver VR6 is mentioning. On many motorcycles there cannot just be a lot of cold airfeed into the box, that just disturbs the performance by making strange swirwls in the air. A controlled pattern is more wanted. So, I would think that cutting the snorkel to e specific length is the way to go. But of course this is all offset, depending of each engine type, state of tune, and is also changed, if you introduce a changed variable, such adding other cams later on etc. Only a rolling road could tell that. And yet some motorcycle tests have shown a ram air effect to give some 4-6 bhp more that just standing still on a bench.

On my motorcycles carbs I've experimented with different gasvalves, )or rather different cutting of the opening on them), and a bit smaller hole created bigger airspeed,which led to an increase of two Bhp's in power.

On a forced fed engine like a G60 or turbo'ed, it's completely different, as it can eat enourmously more air.

I'm sure someone here did a test on a charged engine, so maybe they could tell?

 

Cheers,

Redfox.

Edited December 11, 2012 by Redfox

[Billzeebub 1]

Standard airbox with snorkel removed definitely gets my vote. Mine also has a K&N Panel Filter. Sounds sublime and looks stock.

[Jim 1]

Does the snorkel in the VR6 airbox simply tap out?

[Tempest 0]

Remember the noise Jim's former G60 made without the snorkel (nice at first, but then just headache inducing on a longer motorway run), and that was enough reason for me to never actually have even tried removing the snorkel inside the airbox of my G60.

 

Tempest

[DSLDave 10]

Is the snorkel the piece of cylindrical duct right at the mouth/inlet of the airbox, before the air hits the paper filter, or is it the piece of duct which the air passes through on its way out of the airbox after going through the filter? Today I removed the piece at the inlet into the box - it seems to make a nice difference which I like the sound of, or maybe its my imagination!

[CazzaVR 0]

Jim, yep it just taps out. The VR one is much shorter & wider than the ones on the 4cyl models.

 

Dave, sounds like you've removed the correct one 8) Sounds so much better without it.

 

I've actually just removed my BMC as the bracket is knackered, so I'm back to the stock box inc snorkel. It's soooooo much quieter! It's nice for a change, but will defo put the BMC back on when I have a new bracket sorted. Just can't beat the sound 8)

[Jim 1]

Remember the noise Jim's former G60 made without the snorkel (nice at first, but then just headache inducing on a longer motorway run), and that was enough reason for me to never actually have even tried removing the snorkel inside the airbox of my G60.

 

Tempest

 

Yeah - it was horrendous. I think it won't be quite as tedious on the VR6 somehow but easy to put back if it sucks! :)

 

Cheers Andy - I will have to go have a go at my airbox then!

[CazzaVR 0]

It's totally livable in a VR. You only get the big growl when you open the throttle fully. It's proportionate to how much you put your foot down, there's no constant noise, so you can pootle along fine without it being obtrusive 8)

[Jim 1]

Great. Standard airbox too quiet... BMC too loud (for me - old man) :)

[CazzaVR 0]

Perfect solution then 8) Let us know what you think :)

[Jim 1]

Nipped over to the garage today and popped the snorkel out of the airbox and pretty pleased with the sound out of the car now. Not too loud, not too quiet.. makes a good noise on a bootful :) Nice one.

[Goldie 2]

This may sound like a silly question but what is the snorkel in the air box?

[CazzaVR 0]

The short pipe from the front of the airbox that pushes up to the back of the headlight. Easily removed by taking the lid off the airbox, filter out and tapping the snorkel out with a hammer.

 

Jim, glad you like it- makes a nice difference without being intrusive 8)

[captainredeye 0]

I think the snorkel is the pipe sticking out on the inside of the airbox I googled it but still not 100%. (I was wrong)

 

Have a question about the bmc cda seen mixed reviews about it some feel it improves throttle response on the vr where as quite a few believe in sticking with the standard air box. From what I have read its a toss up between the two. What do you guys think?

[Harrier 1]

The snorkel is the 'trumpet' type plastic bit at air intake.

I felt an improvement in performance when i fitted my BMC although spoke to Vince at Stealth about it & he didnt think there was any real difference though he reckond most people who had the BMC fitted thought their car felt better for it

[Goldie 2]

The BMC i had on my old one was purely for sound.. I want to keep the standard air box on this one though so am keen to have a try of removing the snorkel..

[captainredeye 0]

The main comment on standard boxes is that it breathes well enough so nothing more is needed, have wondered wether its just the added noise gives you the impression its putting more power out.

[CazzaVR 0]

My old Dragon Green VR gained 7bhp from a BMC.

[captainredeye 0]

Andy was that gain made on the same rolling road as part of test ? I'm looking at this as I want what ever is going to work best with all the ported gas flowed goodies I'm strapping on in the new year.

[DSLDave 10]

Since removing the snorkel on the VR6, I havn't driven the car a whole lot, but enough to know now that I definitely prefer the sound! The sound seems nicer even just cruising at relatively low revs, but noticably nicer when accelerating.