RX Turbo airbox/filter upgrades ?

discopotato03 · Post by **discopotato03** » Thu Mar 18, 2010 9:30 pm

Hi all , I'm curious to hear what people have done about less restrictive filtration on EA82Ts .

I had my airbox open today to check the part number of the Ryco filter elements native to the std airbox . From memory the Ryco part number is A345 and cross referenced in the Rocket cattledog is K&N R33-2010 .
For giggles I asked the local Repco outlet and they want $179 for this K&N element .

I have a near new K&N pod filter kicking around and if I could find a suitable case to put it in I'd consider it .

Whilst inside the airbox I removed the plastic duck on the AFM side and had a look at the lower halfs air inlet from the inner guard . This inlet is way too small and we are going to have to enlarge that for sure if the airbox stays .

I don't suppose early Lib or any of the EJ cars airboxes can be grafted into an L Series ? The larger the airbox and panel the better I'd think .

Ideas ?

Cheers A .

Gannon · Post by **Gannon** » Thu Mar 18, 2010 9:42 pm

The XT6 used the same air box and made 146hp.

Id go ahead with enlarging the inlet to the airbox

Got a few pics of your current engine bay setup?

discopotato03 · Post by **discopotato03** » Thu Mar 18, 2010 10:18 pm

Yes I wondered what the XT6 used so thaks for that info .

I also found another K&N panel filter element and its used on half the Subaru range according to K&N . They say either will fit but this one looks like the better fitting and flowing one for an EFI Ls std airbox .

http://www.knfilters.com/search/product ... od=33-2232

I'll get the link to the other one in a sec .

Gannon pics to you soon of the Turbosmart manifold pressure gauge/boost T/3" engine pipe - from turbo to cat .

Being banished to Novacastria tonight and will get new batteries for daughters digital camera Saturday . Only ever goes flat when I need it ...

Cheers A .

Tother one . http://www.knfilters.com/search/product ... od=33-2010

steptoe · Post by **steptoe** » Thu Mar 18, 2010 10:26 pm

LTurbo has his modified to the extent of having the arse of the lower half of the casing cut out so it is just a frame holding things together with the clip.

That plastic intake set up hidden in the guard is also a water trap, with bends and chambers with water drain holes - as well as cooler air intake from the wheel arch.

Cut the arse out of things and you get some very warm air introduced - not good unless in winter

discopotato03 · Post by **discopotato03** » Sat Mar 20, 2010 2:50 am

I would always find ways to get cold air into an air box , have not had time to see whats inside the guard but later this weekend .
That excuse for a hole it has std is not going to cut it and could stand to be larger on a stock car .

Hmmm - std 105 Hp , all these silly inbuilt restrictions . Still it makes half a dozen slight improvements add up to something useful .

The local Repco mob rang me back yesterday to say that the K&N 33-2232 is on some kind of special at $104 and they're going to get one in from either Canberra or Woy Woy branch . The good thing is I don't have to buy it if it doesn't fit .

Fingers crossed it does , cheers A .

ToyRX · Post by **ToyRX** » Sat Mar 20, 2010 5:05 am

Years ago I was concidering a K&N panel filter for my 91 2.2L GX as i was interested in any power gains from a free flowing filter.
I reasoned that no filter at all would have to be less restrictive than even the best filter so I did some tests.
I left the car std and did some acceleation tests, 2nd gear - 3000-6000rpm, 3rd gear - 3000-6200 rpm (redline), ie accelerate from 2000ish with foot flat and passenger starts stopwatch as you pass through 3000rpm. I repeated each 3 times so I was comfortable I had accurate times.
I then removed the bog std cardboard filter entirely and repeated the test.

Result - no differance at all.

I have since done the same thing on a number of cars including my RSB Legacy each time with the same result.

My conclusion is that in standard form most engines power output is not restricted by the air filter element.
Obviously a modified engine may be a different story, but I would be more inclined to remove and smooth out the rest of the inlet pipes/baffles etc rather than waste $ on a K&N filter.

Gannon · Post by **Gannon** » Sat Mar 20, 2010 5:22 am

ToyRX wrote: in standard form most engines power output is not restricted by the air filter element.
Obviously a modified engine may be a different story

How true.

Pod filters and the like are a rather poor excuse for a filter, i remember picking one up in a autoparts store and the filter looked to be no more than flyscreen, i could see quite easily though it

Even if they did make 1/10th of a HP difference, id still rather the stock filter over an engine full of dust.

discopotato03 · Post by **discopotato03** » Sat Mar 20, 2010 1:17 pm

Some pod filters are but they aren't all created equally . The better designed ones have ways of having a lot of filter area for the space they take up . None of them are much chop if they draw in warm post radiator air no matter how well they flow/filter .

What has changed over the years is that manufacturers are fighting for any simple cheap methods of increasing engine efficiency , that doesn't necessarily mean power but emissions and consumption figures are paramount in a competitive world .

For the humble EA/ER engines none of them are what you'd call highly efficient things and their std output is nothing to get excited about for their 1800 or 2700 cc capacities . To get significant torque/Hp increases you have to give the basic air pump (piston engine) every fighting chance to draw air in and eject hot exhaust gasses with the least possible resistance . The aim is to breathe more air to burn more fuel to achieve higher cylinder pressures and therefore power into the crankshaft .

Now I have no doubt that if I'd had an EJ turbo engine and replaced the rubbish header/manifold system they have and fitted an appropriately sized modern ball bearing turbo to it I could easily run the air box out of airflow enough to get a pressure drop across it . Most turbo Roos have either small or laggy turbos hamstrung by poorly thought out exhaust manifolding .

If you've been around turbo diesel engines long enough you get to know how critical low restriction air filters are and how most of them have some system of measuring pressure drop in the inlet system .
The GE 7FDL V16s I spend a lot of my life around de rate from 4020 to 2850 Hp automatically once the pressure drop across air filters reaches a certain point . They have sensors to monitor boost and pre turbo inlet pressures and go into self protect mode if they reckon its necessary .

Anyway I can live with $104 K&N filter and know its washable , though my cars don't generally get into dusty conditions because I live near the sea .
Its interesting that this K&N 33-2232 element is used in many late 80's/90's Subarus and was eventually replaced by one about 3" longer in some of the noughties era EJ25 powered roos .

http://www.oakos.com/Merchant2/merchant ... ode=KN2232

Gannon just about to power up the digital camera and take a few snaps of some of these things .

Cheers A .

AndrewT · Post by **AndrewT** » Sat Mar 20, 2010 2:01 pm

heh, how much do u really think the engine is being restricted by your air filter?
Take your filter out completely and take it for a blat down some non dusty roads. I bet you notice absolutely zero difference.
The EA82 is the restriction

Just get a cheap pod filter if u are that worried about it but yeah, they don't really filter much. I call them rock filters!

discopotato03 · Post by **discopotato03** » Sat Mar 20, 2010 3:09 pm

I don'y buy cheap filters of any kind .

Gannon has pics and note the one of the airboxes lower halfs air inlet .
Thats a 20c piece sitting in there .

A .

BTW that RB26 GTR engine has a pod in front of its GT3582R turbo and its very close to 500 wheel horsepower , big K&N cone filter with a cold air duct .

No garbage getting into the engine either .