Airbox Vs Pod Back To Back Testing

[Scooby]

Just did some back to back testing using a pair of Blitz steel mesh pods and a stock R32 GTR airbox with paper element filter.

Car pulled 268 rwkw on 10 psi with pods. Fitted airbox and dropped 40 rwkw. Took bottom off airbox and taped panel filter in place, back up to 268 rwkw.

I was a firm believer in using the stock box and panel filter but clearly above certain power levels it has limitations. Just my 2c into the stock airbox vs pods debate.

Cheers

[R31Nismoid]

Got a chance to try a 33 airbox?

Maybe there is a big difference, also depends on the type of panel filter.

Plenty of cars here with near enough results airbox vs pods.

Makes it interesting

[RBwhatever]

Well as long as you can get sufficient air to the airbox you'll be right. This probably means making a bigger hole and snorkel on the thing.

[sewid]

This might be true on an R32 GTR but the airbox developed quite a bit in the 33 and 34 GTR.

[BAMR33]

I like the stock air boxes too, I dropped ~10rwkW when I went back to the stock air box and K&N panel. Except the dyno results were about a week apart so something could have changed. Didn't feel any difference, K&N pod was just heaps noisier.

[T04GTR]

hrmm. seems mines has already proved the standard sized panel filter does work but good test though

[GTRgeoff]

I have a 32 and 33 gtr airbox here and the 32 could do with some significant improvement. The 33 has an extra inlet that runs through the side inner guard.

[Duncan]

pics geoff?

[DLOOOK]

The inlet to the side of the box is actually blocked off(r33 gtr box). It is a resonator. You can pull the end of the resonator off so air goes direcly into the box from the inner guard. u get a slight induction noise too lol

ps anyone wanna give me a guide on how to install a ebc on a rb26?? some say u just unhook the factory solenoid and plug it into the ebc solenoid?? i thoiught u would need to do it on the wastegate side??

[rev210]

bonnet down on those tests?

If not , we aren't anywhere.

[Scooby]

bonnet down on those tests?

If not , we aren't anywhere.

no, bonnet open. i don't agree that we aren't anywhere. i think we can categorically state that the stock airbox will inhibit power due to the size of the orifice in the bottom half - bonnet up or down - but clearly the panel filter (tested up to those power levels) has the capacity to flow sufficient air if fed correctly.

i know there's a lot more to the issues of airflow and under bonnet dynamics but this shows conclusively that the bottom half of the box can't flow sufficient air.

i'm not suggesting that this is the be all and end all of tests, but it does tell us some things for sure. got to start somewhere, suffice to say i was happy with the outcome as i now know more than i did.

Edited September 28, 2007 by Scooby

[R31Nismoid]

Oh bonnet up

sad panda now

[TTT]

no, bonnet open. i don't agree that we aren't anywhere. i think we can categorically state that the stock airbox will inhibit power due to the size of the orifice in the bottom half - bonnet up or down - but clearly the panel filter (tested up to those power levels) has the capacity to flow sufficient air if fed correctly.

i know there's a lot more to the issues of airflow and under bonnet dynamics but this shows conclusively that the bottom half of the box can't flow sufficient air.

i'm not suggesting that this is the be all and end all of tests, but it does tell us some things for sure. got to start somewhere, suffice to say i was happy with the outcome as i now know more than i did.

yes..

but

bonnet up with open to air pod filters will obviously breath better than a sealed box with a small intake.

bonnet down would have shown different results on the pod filters I'd say..

especially say after 2 WOT runs.

[GTRgeoff]

I strongly disagree that at those power figures that the bonnet open or closed would heavily influence pods at all unless heat was a serious issue, and ACT is still cold. Ther is plenty of available air around the headlight. Clearly the 32 box is a restriction but with modification, say a 90mm water pipe flange and a pipe through the inner guard 33 GTR style it would be more than adequate for most track applications.

Some pics for Duncan.

33GTR front and 32 rear

33 GTR

32GTR

33GTR

My custom box prototype on the track car using the std air filter and an internal bellmouth from the HKS pod on the inside top (the only good part of a HKS filter). It's a tight fit around the filter so the tape is only to hold it in position and the afm is mounted directly to the top. The from bar is intended to have slots to help feed it.

[Ronin 09]

340rwkw on stock 32 airbox, no worries.

[GTRgeoff]

So it should make more with a few mods Marcus.

[Gts-t]

340rwkw on stock 32 airbox, no worries.

350 with pods?

[Ronin 09]

So it should make more with a few mods Marcus.

show me the way, oh leader

[bLaQ.bOi]

all i have to say

is if you reallllly realllllyyy give a f**k and want to get the best and most power you want from this ppod vs airbox thing

read up on negative boost, and airflow

then read up on "purge welding"

combine the two

[GTRgeoff]

It's all good mate, I majored in aerodynamics at the one uni in the country with a Mach 3 wind tunnel or what we call a shock tunnel, amongst other useful stuff.

While a simple approach would be to say that at least an extra 40rwkw would be available given Marks experience above, it depends on what the turbos are able to push, mass flow wise in Marcus' case. I forget your setup mate, but a fair guess would be a bit is available at that flow rate. Negative boost theories are all well and good but turbos have one simple role and that is to drag air in and compress it for delivery to the combustion chambers so it overcomes many restrictions, up to a point.

Mark, having a think about this and were any of the turbo inlet hoses constricting? If the restriction to the inlet was enough there may be some cross sectional reduction in the inlets between afm and turbo which is a sure way for the restriction to increase so limiting flow. If hard pipes were used, for example, then they would resist the negative pressure and allow the flow to continue. So just a thought.