Airbox Vs Pod

[R31Nismoid]

You gotta replace the turbo/AFM pipe if you wanna keep the airbox.

it has a very bad habit of being sucked closed, even more-so on GTRs

[rev210]

If you are able to retain the factory airbox then consider it's going to require effort and money to make any pod setup just as good. You can also modify the factory airbox with an extra or better air feed to improve it at low cost too.

An airpod is really for when you have gotten stuck with turbo plumbing on big turbos that are larger or some other situation. It's just a part of a bigger bloody hassle that comes with bigger power setups.

Try a dyno with the bonnet 'down' and see how much power a pod loses over the factory airbox. You need a very good cold air induction box to get back only what you lose, hardly worth the effort. Every comparison of 'Wonder Pods' I've seen showing power increases was done with the bonnet 'up', rather pointless.

I have bought recently an R32 gtst with a pod and only a stainless partition in place, The partition does almost nothing (it gets very hot as does the pod inside). Suffice to say I am fixing the issue but, I'd rather not have to.

Some drag cars don't bother with any filters or airboxes at all because it isn't the power they are that concerned with losing so much as the abillity to get what power they have (more than they can use sometimes) through the drivetain (without breaking) and to the ground (controling the traction and transfer). They also strip the engine quite often so little extra bits of dust aren't worried about so much.

[khunjeng]

You gotta replace the turbo/AFM pipe if you wanna keep the airbox.

it has a very bad habit of being sucked closed, even more-so on GTRs

yeah found that out...the car will nearly stall...not good for the turbo either.

I will replace with a new AFM pipe but didn't have time so just wacked on my boxed CAI + Unifilter pod for the moment...1.3 bar is running nice with it

On the dyno it was happening at about 235rwkw mark. As for power loss...well if there is NO air...no pwr.

As for the topics of ARC boxes...for a GTST you can only have 1 intake mod in Vic...so choose between the the stock airbox and IC...we all know what needs upgrading first. 4 a GTR.. no dramas.

SO in summary...intake stock setup is good for about 230rwkw....need to replace both the filter and the AFM pipe - or wotever its called, the one to the turbo. Or for my setup it was good to 0.95 bar or roughly 235rwkw - on my setup.

Some ppl pms me about how I know...it was on the dyno..I saw it!

[sewid]

GTR airbox is different to GTS-t. At least in the 34. GTR has two air intakes. Snorkel and wheel well.

[Wheezy]

spot on beavon, found on silvias too at around 1bar the rubber hose sucks shut....

[khunjeng]

GTR airbox is different to GTS-t. At least in the 34. GTR has two air intakes. Snorkel and wheel well.

yeah I have designed a new intake which is quite similar for the stock GTST..just need ot make it now

[AWD2Go]

I have seen dyno results with the factory hose replaced with an aftermarket pipe and it actually made more power, apparently the ripples in the factory rubber hose can cause the air to be disturbed fairly dramatically.

[GeeTR]

Edited my Friday, non car related response

M

Edited January 19, 2007 by GeeTR

[khunjeng]

I have seen dyno results with the factory hose replaced with an aftermarket pipe and it actually made more power, apparently the ripples in the factory rubber hose can cause the air to be disturbed fairly dramatically.

So this means there IS a restriction with a stock box even if u replace the intake pipe ur only masking the issue. How much, dunno. But its obviously a restriction if it doesnt occur with a pod. However with the pod ur missing out on other things like colder air and pressure drop so prob. evens out in general.

So you can just knock another hole in the lid of the stock box to try and fix the restriction...But I actually took my lid off on the dyno and saw the pipe still suck in a bit.

So for me its:

1. New Intake pipe.

2. New Lid and snorkel to look stock.

3. No defect issues

[Cubes]

I have seen dyno results with the factory hose replaced with an aftermarket pipe and it actually made more power, apparently the ripples in the factory rubber hose can cause the air to be disturbed fairly dramatically.

So this means there IS a restriction with a stock box even if u replace the intake pipe ur only masking the issue. How much, dunno. But its obviously a restriction if it doesnt occur with a pod. However with the pod ur missing out on other things like colder air and pressure drop so prob. evens out in general.

So you can just knock another hole in the lid of the stock box to try and fix the restriction...But I actually took my lid off on the dyno and saw the pipe still suck in a bit.

So for me its:

1. New Intake pipe.

2. New Lid and snorkel to look stock.

3. No defect issues

Its quite possible the intake pipe its self is contributing to the restriction, its quite lumpy in there and we all know air likes a smooth flat polished surface. Which is why exhaust ports are polished. Improve flow due to reduced turbulence.

Either way I think the best option is to replace the intake pipe. The turbo is doing the work sucking the air so there's no direct pumping losses as an N/A would experience with a slight restriction in the inlet tract.

So yes Mask the problem as you call it. Its not necessarily loosing power anyway. Just keeping those defects away.

As said above. If the car were N/A its a complete different story.

N/A = ditch the afm, remove 'any' possible restriction there is as it all contributes to pumping losses.

[khunjeng]

Its quite possible the intake pipe its self is contributing to the restriction, its quite lumpy in there and we all know air likes a smooth flat polished surface. Which is why exhaust ports are polished. Improve flow due to reduced turbulence.

Either way I think the best option is to replace the intake pipe. The turbo is doing the work sucking the air so there's no direct pumping losses as an N/A would experience with a slight restriction in the inlet tract.

So yes Mask the problem as you call it. Its not necessarily loosing power anyway. Just keeping those defects away.

As said above. If the car were N/A its a complete different story.

N/A = ditch the afm, remove 'any' possible restriction there is as it all contributes to pumping losses.

Dont disagree. But during the test I replaced the stock box with a pod and issue does not occur at all. So therefore my point was the pipe is not the main cause of restriction as it remains constant in the test, however crap it might be .

If ur gonna go to the trouble of replacing the intake...I might as well do it properly and remove all the restriction buy venting the box lid better.

As for NAs...I have made about 3 setups for my NA fto. The stock box with new intake pipe got me about 4rwkw of stock...cos the stock one was so bad, the pod gave nothing...infact my testing showed slight worse results with the pod.

[rev210]

that rubber turbo to afm pipe is worth a few hp odd if you turf it for something better for sure.

[khunjeng]

that rubber turbo to afm pipe is worth a few hp odd if you turf it for something better for sure.

we will find out soon enough.

[GTRgeoff]

I think the primary problem is the size of the inlet on the stock GTSt airbox, not the actual filter area else GTR's would have trouble with more power.

The ribbed pipe is secondary but can be a major issue when sucking closed at higher power and on hot days so clearly that has to go.

The solution? For me it is a black painted FMIC, opened airbox with Apexi filter (oiled are illegal, see attached docupic from Pauls website so K&N are out) and a replacement hard pipe also black. Leave the heat for the ricers with pods and shiny "look at me, I'm an attention whore" FMIC.

[khunjeng]

couldnt agree more geoff. more venting and a al/ss intake pipe are in order.

for the moment I have boxed up a pod until I can get it all sorted next week.

[Angus Smart]

so the HKS GTR only has the pods to make them sounds good?

and those 9s GTRs also, no performance increase from pods?

most of them 9's gtr's in japa dont even run filters at all.

[khunjeng]

most of them 9's gtr's in japa dont even run filters at all.

yeah but how often do they do rebuilds? also they run on short peroids on a track.

Not useful advice for a street driven car.

[Godzilla32]

Interesting stuff Geoff. Its good to actually read some real facts on what is allowed and whats not. Even the police give mixed answers.

Deren

[T04GTR]

hmmm. well it seems to work for the mines gtr.

just looks boring tho

[T04GTR]

thats a gay rule