Scientific approach to air filter setup

[Mr Revhead]

as above
was very very common for ppl to bring their pod filter equipped altezzas into Toyota complaining it wouldn't run right....

[FLAWLES]

i should really find my uncles dyno runs in his sw20 mr2
he got the most power ( or the less decress in power how ever you want to see it ) with the factory airbox and the factory filter, but the box had a small modifactio done to it via a cold air ( i spose you would say ) induction, with a pipe going straight to it.
was rather interesting

but when i had the vvti 1jzge in my 100 i dynoed the car has is with the airbox and std filter and i think i was netting around about 98rwkw

im one of those pple who like to keep things rather factory under the bonnet so i spent the money on a TRD filter

went back to the dyno and had a gain of 5kws or there abouts over the toyota oem filter ( assuming it was as the car came from a toyota dealer and had a service done prio to leaving )

the 1jzge vvti air boxs have two nice big induction bell mouths great for catching air, i would love to find a vvti 1jzgte airbox but alot of pple bin them



on another note has anyone taking into account resonator box's? on the inlet pipe?
isnt there a massive sceince behind these as well?

[ChaosAD]

Ive got a book somewhere on modifying intakes and I think they recomended removing the piping upstream of the air filter and fitting a pipe from the front of the car to the air box with bell mouths at each end.

[strx7]

I aim for one thing when it comes to filters, to get as much cold air into it as possible. the inlet air temp difference on my corolla between the pod filted being mounted straight onto the compressor and it being mounted under the guard was 40 degrees celcius after going for a drive along the road with the engine bay upto usual hot temp.

[Heylin]

Ive run my MR2 back to back runs with 2 different setups to see what felt better.

I had factory airbox with K&N panel, swapped out for Pod, then put factory airbox back in.

Result was the airbox even with uprated panel seemed to suffocate the car under boost in the mid rpm to high rpm.

Popped the pod back in and its way smoother accross the entire range and definately an improvement in throttle response and accleration.

I have never looked back, I sold the K&N panel and run the same $40 Simota pod filter to this very day (3 years now) cleaned and oiled every 5000 kms for the best possible filtration and flow.

So with the MR2 Turbo at least I can say that the factory airbox is crap.

[bbq1988]

Ive run my MR2 back to back runs with 2 different setups to see what felt better.

I had factory airbox with K&N panel, swapped out for Pod, then put factory airbox back in.

Result was the airbox even with uprated panel seemed to suffocate the car under boost in the mid rpm to high rpm.

Popped the pod back in and its way smoother accross the entire range and definately an improvement in throttle response and accleration.

I have never looked back, I sold the K&N panel and run the same $40 Simota pod filter to this very day (3 years now) cleaned and oiled every 5000 kms for the best possible filtration and flow.

So with the MR2 Turbo at least I can say that the factory airbox is crap.

I Had the same problem in my caldina. So i took an airsaw to the bottom of the air box and removed 80% of the bottom, made a huge change high in the rev's

[Emperor]

Complete opposite with Forester.
It came with a Blitz pod filter, and ran real rough, overfuelled, wasnt smooth.

Got given a factory airbox with standard(but new) filter, put that in and it ran alot better! A noticeable power difference and alot smoother, also better fuel economy.
But I think it was also to do with the fact I plumbed the GFB BOV back in too.

[RomanV]

Result was the airbox even with uprated panel seemed to suffocate the car under boost in the mid rpm to high rpm.

So with the MR2 Turbo at least I can say that the factory airbox is crap.

That's the thing though... Do you have any verifiable evidence apart from Butt dyno? How it 'feels' isnt a particularly reliable method.

My car felt faster when it was 20hp down, and lacking midrange and low rpm power... Because you'd get more of a surge when it got to the higher RPM range.

When it was all fixed, it didnt feel like it had such a kick, because it would pull from way lower rpms. I wouldnt have known, if not for objective testing.

Al's old SW20 had 189kw ATW with standard airbox/filter/etc if I recall.

The problem with relying on 'feel' is that your brain also somewhat factors in how it sounds etc too. A car that sounds gruntier feels like it's faster, in most instances.

[1I1]

Blacebo effect.

Because you changed/modified something it must be better/faster

[Lurkin]

my 2c

attempted a while ago to see how 'cold' a 'cold' air intake actually is...

put a temp sensor in between the intake plenum and pod..

the temperatures were nothing like 'cold' - was abit disappointed really.. so i've always assumed it was 'colder' and left it at that.

ended up leaving with a cheap crappy pod - as every other option involved spending money.. would be interesting to compare the temperature to a factory box...

[RomanV]

Yeah although most/all factory intakes do come from a 'cold air' source, they are also generally made from black plastic, which I'm fairly sure heat soaks like a mofo?

Wonder how much of a difference it would make to insulate a factory airbox etc a bit better.

[sergei]

I doubt black plastic would heat soak as you describe. Plastic is insulator.
Black is good at absorbing heat and equally as good at radiating heat.
Plastic also has low heat capacity.

[Lurkin]

cant tell - dont have one.

I tried putting in an aluminim shield - to insulate the pod from the engine bay - made no difference in temp. I must say it was a pretty weak attempt - it wasnt completely sealed off.

have always wondered if it would actually make much difference if I bothered to make a proper sealed compartment for it - and wrapped the rest of the piping

got sick of wasting money on it... so gave up while I was ahead

[Prymal]

thats why the turbo pipes on the typhoons were revised too ..

the Xr6 turbos have horrible restriction in htat department , and hen changed open up a heap of free ponies

[RomanV]

I doubt black plastic would heat soak as you describe. Plastic is insulator.
Black is good at absorbing heat and equally as good at radiating heat.
Plastic also has low heat capacity.

Aaah, is it? I thought plastic was a good conductor of heat.

Well, that's good news for me then.

Speaking of air intake setups, I've just had a thought about mine.

I've moved the airflow meter housing to be part of the airbox around the intake runners, as it's quad throttle setup.

Hope I wont get much/any stand off, as hot wire airflow meter + stand off = fun times

[crispy'86]

I got given a few magazines a while ago..an aussie mag called zoom?? and in one was an article on exactly this topic. Testing out different setups for air filters and airboxes, from what i recall they had used a bellmouth design in the entry air, then same from the intake pipe out of the airbox to the engine from the air filter box. Had a noticable gain in hp although nothing as stupid as "15hp by putsing in my poddy aaauuuuu"

i'll see if i can dig it out

[B_giB]

Three words, pods are gay.

Nothing wrong with factory set ups, I know from experience with the Altezza... put a pod on and had to put up with it for a while as I misplaced some of the factory parts, Went from going through a tank of gas in 300km's and going to 450 km's out of a tank, and the midrange torque is alot better now, like a new car...

And then there was my AE101, I put a TRD panel filter in that, was great, and put a pod filter in that, and it was crap...

Newer cars especially have fantastic setups from factory.

[iOnic]

Three words, pods are [person of homosexual orientation].

I wouldn't go to that extent. Your comparisons are based on a properly designed intake tract VS an intake manifold with a pod filter on the end of it ingesting all the heat of your engine bay with no actual proper airflow/air velocity to the area...Is it really the pod filter's fault that your car ran like crap or is it yours for not implementing a properly designed system with the pod filter?

Your results are similar to what I'd expect the gains to be from just adding a fart cannon to the end of the exhaust vs designing a proper exhaust system - the factory exhaust would probably end up being better, does that mean all aftermarket exhausts are therefore bad? Food for thought

[79rolla]

also a factory air box is not always an option, for example bigger turbo setup or custom manifold or turbo conversion, then i would rather a pod then no filter... and as above just ramming a pod on the end wont do much, it needs to be setup correctly with new intake and proper ducting/heat sheaild i would imagine (no i have no proof to back u this clame)

but you have to remember not everyone is after the maximum power they can get out of there cars, they just want something nice that not a nan spec peace of poos.

(says the one with a pod sitting on top of the carb on my ute lol)

also some cars have stupid air box designed like a gt starlet witch runs from the turbo to the back of the engine bay on the other side then has a small intake running to the front, witch all gets in the way wen doing a front mount conversion

so pod not always best but some times the lesser of two evils

my 3 cents

[B_giB]

my 3 cents

Dam recession...