R32 Gts-t Airbox and CAI

[Lithius]

Hey there, I have a freshly imported '89 R32 Gts-t. It has come with the usual exposed APEXi pod filter, which I am now lead to believe might very well be worse for performance than a completely stock airbox (Due to it sucking in hot underbonnet air etc) On a number of cars, replacing the stock airbox with an exposed pot filter, no matter what brand it is, results in a loss of rev range power.

Just wondering what people with an R32 Gts-t or similar have opted for in regards to their air management. Is there any off the shelf airbox that will fit my APEXi pod filter? as it's a great filter- it's just not getting the cold air it needs, so I'd rather fix this than replace the filter. If there isn't an aftermarket airbox, I figure my best option here is to build a custom box and run a snorkel that vents through one of the openings in my aftermarket front bar?

Has anyone done this and has pictures and/or results of their setup? Or done anything else that has given them good results? Cost? Materials used? I'm just unsure of how I should proceed... I see there's a group buy for a Unifilter setup with filter and box, but I already have a filter and would prefer to use it. I will be using a manometre to measure pressure drop... i'd just like to be able to build something straight up that'll give me good results =)

[predator]

There is a guide in FAQ section I believe on creating an R32 cold air feed.

I am not sure about GTS-T stock airbox myself.. Its got a little feed to the front bar through a tiny **** under the headlight, and I can hardly see how it gets enough cold air.. Its much worse than the R33 stock setup.

[B0oStEr]

I'm looking into the same issues on my '89.

Got defected for k&n pod.

I don't see anything wrong with the factory abox that a decent panelfilter wouldn't fix but

the inlet pipes to the stock airbox look fairly restrictive so I'm trying to find out if the similar but larger gtr ones will fit up to the stock gtst airbox. The gtr inlet ducts get air from a resonator box that sits inside the left guard where the stock gtst intercooler is.

I don't think I would use the resonator box but the pipe from the air box to under the headlight looks like it would work well on the gtst.

I might face my inlet down behind the frontbar because if the opening is facing forwards the airbox will quickly fill with bugs, dirt and maybe water too.

I'm still trying to find some gtr ducts that I can try them out.

[WazR32GTSt]

my setup as i posted a while ago:

http://www.skylinesaustralia.com/forums/sh...ight=r32+airbox

refer to that thread if you like...

[CerealKiller]

when I get around to it I'll post some pics of my intake pipe to my airbox. It's raining at the moment so it may be in a few days.

[Lithius]

Thanks for the links guys, I did search but didn't come up with much. I'll take a look at those. If you could post some pics when you get the chance that'd be great cereal.

Booster the only problem a downward facing intake duct is that it won't be pressurised by the car's forward movement. I know a wire grille can be used to prevent bugs and the like but i'm not too sure how to position a front facing duct so as to not pickup excess water.

Edit: Had a look at your setup Waz... that's kinda what I was thinking of. A length of aggy pipe (nice and bendable this stuff) running to a funnel that's sealed onto a duct in the front bar. You don't have any problem with water or anything getting in there? And is there any noticeable difference in throttle respone? Of course i'd still have to make a custom airbox to fit my pod filter.

[Lithius]

Here's a link to the thread predator mentioned. It has some interesting arguments for using a Pod Filter vs standard airbox with Panel Filter, and peoples designs (pictures) for custom CAI jobs.

http://www.skylinesaustralia.com/forums/sh...ead.php?t=13003

Seeing as tho Pod Filters seem to be one of the most common reasons for people being defected, I'm considering going back to a standard airbox with panel filter and modified air intake so that it gets more air into it. I really wish I had the original airbox tho so that I could use a manometre to check for pressure loss through the system =(

Edit: Forgot the link

[Cubes]

I was making 164rwkw on 1bar, 3" turbo back, stock ecu, stock airbox & stock filter.

We did a little test to see if the POD indeed makes a difference, we dropped in a bran new K&N pod, the bonnet was open and the pod lifted so it was receiving cool air.

The dyno runs were exactly the same. Not 1rwkw difference.

However It did make a heap more noise, possibly leading some to belive it makes their car faster?

At those power levels (basically max out power of the stock turbo) the stock airbox is fine.

[Lithius]

Yes but dyno figures don't really make for an accurate comparison measurement in this situation... Would be good to have some dyno figures from when the car was actually being driven, with variables such as pod type, box system, cai duct location, air temperature and all that. Unfortunetly I don't think that's going to happen tho =/ But yeah, POD on its own = waste of money.

"As a rule of thumb, expect the peak power to improve by 1 per cent for every 4 degrees C temperaute decrease of the intake air temperature"

So basically any car, no matter what its power output, can and will benefit from whichever air intake system provides it with the coolest (more dense) air, and from an air intake system that has a minimal drop in air pressure (can occur in the intake flow, airbox w/ filter, and/or airflow metre)

Drops in air pressure also have very noticeable negative effects on a cars peformance. When I say drops in air pressure basically it means the air isn't flowing well for some reason. As an example from a book I have (21st Century Performance by Julian Edgar if anyone is interested, great book) is a Surbaru Liberty where air pressure drop was reduced by 70% and the 0-100km/h time dropped from 6.5 to 6.1... just from the fitting of a new snorkle.

I guess the only real way to figure out what's best for your car is to try different setups and take readings with a thermometre and manometre. So I guess i'm really curious if anyone has actually done these readings?

Edit: One of the major problems with the stock r32 airbox may simply be its snorkel is too restrictive. When I get my car on the road in another 2 weeks or so I will do the testing and post results for before and after modifying the stock air intake system.

[Cubes]

I was illustrating that the stock airbox with the stock cai doesn't pose an airflow restriction at 164rwkw.

In this situation it is very relevant but only part of the equation.

I now have a 100mm PVC using 2 x 45degree bends entering my stock airbox.

The inner guard 45degree bend faces towards the front of the car. The other 45degree bend slips in to the lower 45degree bend and points in to the airbox.

It did require a 100mm dia hole to be cut in to the inner guard.

I cut away the bottom and part of the side of the airbox so the 45degree bend mated up smoothly.

Looking in the engine bay it is damn difficult to see unless you really know what you are looking for.

Only a really small part of the painted black pvc pipe can be see.

Modify the stock snorkle to sit back in its stock position and it would hide the edge of the pvc pipe.

The issue with pods sitting in a box is the uneven airflow through the element. This could very well pose a flow restriction.

EDIT: I have also found having positive pressure not a good thing when idling.

If I direct the bend directly in the airflow the car will not idle smooth, instead it will hunt up to 2000rpm and down to 1000rpm over and over.

This is when cruising at anything over 50km/h then dropping it in neutral.

Point the 100mm snorkle away from the direct airflow stream and the idle is perfect.

Not that you drive around idling in neutral. lol

[Lithius]

So where exactly does your snorkel get air from? Any pics? According to what i'm reading the wheel arch area is an area of low pressure and not ideal for air intake. Is it possible that's what's causing the rough idle?

[BezerkR32]

Hey there, I have a freshly imported '89 R32 Gts-t. It has come with the usual exposed APEXi pod filter, which I am now lead to believe might very well be worse for performance than a completely stock airbox (Due to it sucking in hot underbonnet air etc) On a number of cars, replacing the stock airbox with an exposed pot filter, no matter what brand it is, results in a loss of rev range power.

Just wondering what people with an R32 Gts-t or similar have opted for in regards to their air management. Is there any off the shelf airbox that will fit my APEXi pod filter? as it's a great filter- it's just not getting the cold air it needs, so I'd rather fix this than replace the filter. If there isn't an aftermarket airbox, I figure my best option here is to build a custom box and run a snorkel that vents through one of the openings in my aftermarket front bar?

Has anyone done this and has pictures and/or results of their setup? Or done anything else that has given them good results? Cost? Materials used? I'm just unsure of how I should proceed... I see there's a group buy for a Unifilter setup with filter and box, but I already have a filter and would prefer to use it. I will be using a manometre to measure pressure drop... i'd just like to be able to build something straight up that'll give me good results =)

are you running factory intercooler or aftermarket frontmount? We have piped pods behind front bar whre aftermarket cooler is fitted with excellent results.

[Cubes]

ok i'll dig up some pics.

Sorry not the inner guard but the front bumper where the stock IC was.

Its not a low pressure, anything but its super high pressure.

This is what is causing the bad idle when cruising and dumping it in neutral.

The air is drawing stuff all air, the snorkle see's high pressure so it forces air in disturbing the afm. The bad idle when doing so is pointless mentioning really as who drives around and drops it in neutral. haha

When it was really windy not so long ago I felt the car shake and saw the AFM voltage jump, it was a fluke I was watching the afm voltage at the time on the pfc h/c.

That being said with my little snorkle (not extending all the way to the front bar like some do) I get quite a wet airfilter.

Which is not good, especially for the paper types. I don't think its too good for the afm either.

Positioning the pod in the front bumper in the position of the stock IC would see much more water.

[siksII]

ok i'll dig up some pics.

 

Sorry not the inner guard but the front bumper where the stock IC was.  

Its not a low pressure, anything but its super high pressure.

 

This is what is causing the bad idle when cruising and dumping it in neutral.

The air is drawing stuff all air, the snorkle see's high pressure so it forces air in disturbing the afm. The bad idle when doing so is pointless mentioning really as who drives around and drops it in neutral. haha

 

When it was really windy not so long ago I felt the car shake and saw the AFM voltage jump, it was a fluke I was watching the afm voltage at the time on the pfc h/c.

 

That being said with my little snorkle (not extending all the way to the front bar like some do) I get quite a wet airfilter.

 

Which is not good, especially for the paper types. I don't think its too good for the afm either.

 

Positioning the pod in the front bumper in the position of the stock IC would see much more water.

ive always wondered about this in relation to putting a pod in direct airflow, thanks for clearing it up.

i have a 33, and since i have a fmic the piping gets in the way of the standard snorkel, so at the moment i just have the std paper element in the stock box without the snorkel

this means very high intake temps, and im sure it is leading to obviously power loss but also my afm seems to read very high and the car runs very rich when it heats up.

so i have ordered a pod, and im either going to build a box around it with some piping coming to inside the box from underneath

or as someone has mentioned, get piping made up and place it behind the front bar, not sure about how dirty/wet it will get though and if it will make a worthwhile difference when compared to the other (box) option.

what do u think?

[Lithius]

Yeah I run an aftermarket intercooler... not sure how much room is down there tho i'll have to take a look. Does anyone have any pictures of their setup where they've got the pod filter down below/behind their intercooler?

Also can I get defected for a pod filter even if it's on my engineering certificate? I just brought the car in from japan and got it engineered so all modifications should be on it right? havn't actually got it yet.. it's being mailed down to me.

[BezerkR32]

Yeah I run an aftermarket intercooler... not sure how much room is down there tho i'll have to take a look. Does anyone have any pictures of their setup where they've got the pod filter down below/behind their intercooler?

Also can I get defected for a pod filter even if it's on my engineering certificate? I just brought the car in from japan and got it engineered so all modifications should be on it right? havn't actually got it yet.. it's being mailed down to me.

you have heaps of room then, as far as defect, yes you can but out of sight out of mind. They are well hidden. If you paint pipework in engine bay black, you cant tell.

[BezerkR32]

email me at [email protected] i will email you back some photos.

[Lithius]

Good little article here for creating a ram-air setup for your airbox.

http://autospeed.drive.com.au/cms/A_2518/article.html

[CerealKiller]

this is my cold air intake on the stock airbox.

Basically I just removed the stock snorkel and replaced it with a 50mm flex pipe. (I have a lot spare if anyone's interested). Took me about 30 minutes or so.

[WazR32GTSt]

a good place for cheap flexible pipe is clark rubber

they have a variety of diameters and the inside of the pipe is smooth, even when the pipe is bent... great for CAI