Best Air Intake?

[shrew]

hi guys

is there a definitive answer to what is the best air intake please?

some say a better element in the standard box, other go with the cone on the maf, and then others pipe three times round the engine bay!

its not the expense i mind, but it has to be justifiable, so what do yer reckon, what do i buy and where from?

thanks in advance,

shrew

[Nick Mann]

You need cold air. A cone/mushroom filter in the engine bay is not the way forwards.

I would personally say a good panel filter in the standard air box. If you want to do anything more, then ARC do a cold air kit, I think? The ultimate is probably a battery re-location kit and then a cold air feed where the battery used to be.

[bradc]

I agree with the panel filter.

The ARC isn't really a cold air intake, it just takes in air from the warm side of the engine bay rather than the hot side

The best possible bet would be to remove the battery as Nick said

[Kieran]

I agree with the above. A high flow filter in the standard airbox is the best trade off between flow and intake temp, unless you can get a forced cold air feed to the filter.

[psbarham]

unless you can get a forced cold air feed to the filter.

i found a fantastic bit of info about how much these forced air airboxes acctually gain the other day.
you hear of all these people saying it'll give hooooge increases in power. wrong so very very wrong, you know the fantasticaly sculpted and designed intakes on a n F1 car, the ones above the drivers head , carefully designed on cfd software to sit in the smooth fast flowing air.
you'll love this,


at 190 mph they are worth 25 bhp.
thats it , not a bloody lot really, so fitting a pipe to the front bumper on ours will give a ram effect of frick all, all you will get is some cool air, as long as the pipe isn't in a negative pressure area wind tunnel anyone ?

[valmes]

i found a fantastic bit of info about how much these forced air airboxes acctually gain the other day.
you hear of all these people saying it'll give hooooge increases in power. wrong so very very wrong, you know the fantasticaly sculpted and designed intakes on a n F1 car, the ones above the drivers head , carefully designed on cfd software to sit in the smooth fast flowing air.
you'll love this,


at 190 mph they are worth 25 bhp.
thats it , not a bloody lot really, so fitting a pipe to the front bumper on ours will give a ram effect of frick all, all you will get is some cool air, as long as the pipe isn't in a negative pressure area wind tunnel anyone ?

Hmmm... you can't compare F1 car to a road car, not like that anyway...

Flow and temperature will do quite a lot!!!

http://msport.co.nz/viewtopic.php?t=2413

[Paul C]

i found a fantastic bit of info about how much these forced air airboxes acctually gain the other day.
you hear of all these people saying it'll give hooooge increases in power. wrong so very very wrong, you know the fantasticaly sculpted and designed intakes on a n F1 car, the ones above the drivers head , carefully designed on cfd software to sit in the smooth fast flowing air.
you'll love this,


at 190 mph they are worth 25 bhp.
thats it , not a bloody lot really, so fitting a pipe to the front bumper on ours will give a ram effect of frick all, all you will get is some cool air, as long as the pipe isn't in a negative pressure area wind tunnel anyone ?

Although we wont get 25bhp the colder air must be the bonus point. i have been experimenting with the air intake for a while and have found that the vr4 is a b*tch to keep cool.I have so far have a enclosed bmc cda filter fed via a 73mm samco hose. the next step is to create an enclosed air scoop behind the headlight to keep heat out and cold in and maybe a a bonnet vent in the same area. I have found that with the recent cold weather and my earlier starts at work thet the car feels like a rocket,but when the engine bay starts to warm after long journeys there is slight power loss.

So what you need is early winter mornings and short journey's.

[shrew]

Hi Paul

i'd certainly agree and know the principles of cool and damp air, or heavy air as we call it with our motorcycling hat on.

my experience with bikes is the same as yourself, i.e on a cold and crisp morning, any engine bar none will benefit everywhere from the cool damp dense winter air, mainly being that as a cold and denser air, there is more oxygen in the mix for the same given volume, so bigger bang per squeeze.

most noticably is usually the response which is so much more when the air is like this eh?

so how can we replictae this best?

i agree with the idea that the japs didn't develop the air intake the way it is for nothing, and it works very well, particularly at keeping the air temps down obviously.

but, if i'm going to run more boost, am i simply going to run out of air i can pull through the stock set up to get the gain i should?

so, as a mixture of threads and info, how does this sound?

a - junk the battery out the way
b - create as large as poss enclosure where the battery was behind the head lamp using sheet metal, or plastic with heat a reflective addition. Constructed simply as an upright wall that will meet the underside of the closed bonnet.
c - smooth large (2.5+") bore pipe from the MAF, through a sealed opening in the enclosure, with a branded cone filter on it.
d - vent as much air into the enclosure via flexible pipe from as many forward facing openings in the grill and lower skirt as poss.
e - either, bonnet grills over the engine to help vent engine temp, OR, vent above the enclosure area to further reduce that area's temp, although, on the move could this create a vacuum that would suck the air out the vent before the cone filter has a chance to grab it and then starve it of even more air?

How am i doing so far?

cheers guys, keep it coming.

shrew

[valmes]

You are on the right path
Can't argue with your planning

[valmes]

I think Gly has posted pictures of his custom made air intake setup... you should search around for that thread.

[shrew]

Great stuff, i look it up

so back to one of my original questions...

whose dump / bov should i use?

its pretty hard locating one for a legnum vr4, so does the evo fitting kit fit for example?

shrew

[Kieran]

so fitting a pipe to the front bumper on ours will give a ram effect of frick all, all you will get is some cool air, as long as the pipe isn't in a negative pressure area wind tunnel anyone ?

Oh yeah, there's no ram effect, it's more the fact that it'll be getting a source of fresh, cold air rather than warm engine bay air.

[shrew]

hi kieran

i'm glad you popped up for a comment as i was just reading some other threads with your name on it!

back in 2005 you said you were ordering your DTA blow of valve, the HKS SSQV i think it was.

how did that go? are you still running it? any problems, and which kit did you order?

thanks kieran

cheers,
shrew

[Kieran]

Shrew - Mine was a 2nd hand one from RHD Japan - they often use ebay to get rid of old/used stock that's not good enough for the main website.

I ran the valve for a few months, but I replaced it as I disliked the noise that the SSQV makes in particular (it's a very high frequency and shrill Pssshht!!) and also because at the time, I was suspicious that it was the cause of stalling issues - in fact it made little difference; I later found a couple of split vaccuum lines. In fact here's the original advert:

http://www.clubvr4.com/forum/showthread.php?t=19859

When I first fitted the valve I was still at standard boost and it didn't feel much different, maybe *slightly* more urgent, but it was probably placebo.

I am currently using an EVO recirc valve (the evo uses the same fittings as the VR-4). Interestingly, I notice that having gone back to recirc, my gearchanges seem smoother - I think Pezza found the same, but I am at a loss as to why this should be!

Bottom line on the SSQV? Well, it's twin-piston design and the fact that on boost the air is always trying to force the valve shut makes it a safe, leak free bet and many people use them on here and are happy with them. There is a specific SSQV kit for the legnum, which makes fitment easier and they don't seem to have caused anyone any major trouble so far. Depends on whether or not you can live with the noise - I couldn't!

[valmes]

I use HKS SSQV, although it's moved from the original location, which, in my opinion was not a proper place for a BOV.

Even if its not EC5W specific kit, there is not much involved in fitting it. Same as with Walbro fuel pump or oil catch tank...

[rees]

why ? where do you recommend/have your dump valve located ?
also any decnt alternatives to the hks sqv ? that sound better anyone?

[psbarham]

Oh yeah, there's no ram effect, it's more the fact that it'll be getting a source of fresh, cold air rather than warm engine bay air.

oh i know that, i thought I'd post it up before you get some wise ass going 'oh and then you get the ram effect at 60+mph which is worth a trillion bhp' the only benefit of the extra intake is the cold air.

i remember reading a brilliant technical article in performance bikes by a genius called John Robinson (rip) basically Kawasaki were saying the ram air effect was worth 20 odd bhp at 100 ish mph , so performance bikes rigged up increasingly longer and longer extensions to the air scoop on the fairing to measure pressure in the airbox at 100mph , armed with this info the put the bike on the dyno and rigged up a a fan that would deliver enough flow to give the varying pressures , it turned out that to get a noticeable increase in power at 100 mph the scoop would have to extend about 10-12 inches( can't remember exactly it was 15 yrs ago) in front of the fairing