Pod Filter and Exhaust

[drewc]

Hey guys.

Wanted to make some mods to the beast. Just want to get a little bit of extra performace and i would be happy. I realise that the following might only improve the kw's by a couple but what kind of difference is reponse will i get. I have no experience in this so your imput if you know what you are talking about would be great.

1) Pod filter - K & N

2) Exhaust

I know nothing about exhausts so what do i need. I just want something with a great sound and will turn some heads.

Also can someone confrim that a POD filter will be better than a panel filter. I know the pod looks great but will it be better and also heard pods are illegal and if the car gets pulled i could get asked to take it off or worse defected.

please let me know what i should be spending on an exhaust so i dont get ripped and what your experience with the pod vs panel filters and what the imrovements would be like

thanks

drew

[thirteen]

pod filters are illegal and if the cops pull you over, you will earn a defect. Also if u get a pod filter u will need to shield it from engine heat as they can't sit inside the airbox. Police will know, because its easy to hear a pod filter roar as you accelerate.

I would recommend a panel filter with a de-restricted airbox as it will give u similar if not better gains whilst remaining pretty stock looking. U will still get a little bit of induction noise with this setup if thats what you wanted from a pod filter.

The exhaust, a 2 inch or 2 and 1/4 catback exhaust with a small resonator and rear muffler of your choice should give a good sound. Canons tend to drone a lot more and i personally dont really like the sound of them.

goodluck :)

[break]

^^^ basically what he said.

If you don't fit heat shielding and give the pod a nice big cold air intake pipe your actually going to get less power than standard according to dyno tests.

As for the exhaust... don't go bigger than a '2 pipe. As for the sound... this is really determined by the resonators in the exhaust system... and the muffler... so if you want noise make sure you get a suitable resonator/muffler setup.

Just destrict your airbox and fit a quality panel filter. If your really up for it drill a bigger inlet hole into the box and fit a much bigger intake pipe.

[1OPL2C]

what is derestircting the airbox? what do you actually do?

[Degen-Astra]

If you want to go an after market filter...try a Pipercross or Raid air filter as they are eclosed pod filters.

As a 1.8 you wouldnt go larger than a 2.25inch.
http://www.sportcompactcarweb.com/tech/9912scc_ssbbpart2/index.html

Have a read of that link.

[break]

Check out this thread on how to de-restrict the airbox of a car.

http://opelaus.com/phpBB2-3/viewtopic.php?t=1453

[sir-sri]

break and others have you on the right track with the pod..forget it, just do a nice cold air intake to the current box. I wouldn't even replace the factory filter, usually there is practically no difference in flow between it and aftermarket ones, and if there is, you really have to ask, is it filtering as well?

On the exhaust, one thing I have never really had an answer on is how will it effect the tune of the car...are you going to end up running to rich or lean and thus loosing power. The old wives tale of too big an exhaust on a n/a car is false, but in the end the result is the same, you loose power becase your flowing so much more exhaust gas out than before the ecu doesn't know whats going on and you end up loosing bottom end power.

I am keen to do a nice exhaust (quiet as possible but free flowing) and a CAI just want to learn more about how it will effect tuning before I go ahead.

[break]

Your not 100% right there sir-sri when it comes to exhaust sizing and power.

The more free-flowing the exhaust, the more top end power you can retrieve from the car. The problem, however, is that by increasing the exhaust past the point where there is not enough back pressure for the engine will in turn remove torque (and subsequently, power) from the bottom end of the rev range, where an engine needs it the most.

For example, a friend of mine has a SR20DE powered silvia.... however it was imported with a FULL '4 exhaust system (thats from the extractors ALL the way out to the tip :screwy: ). Anyway, on the dyno you could see just how poor the torque was down low in the revs. Dropping the size of the exhaust down to say '2, in his case, would remove top end power, but would improve torque accross the rev range, especially down low.

Hope that makes sense.

As for a POD. They are just as effective as a panel filter... no more no less.... and without setting them up properly (ie. in thier own enclosed airbox with a propper cold air intake) you will actually have the same effect as running the intake for your airbox to the hot air behind your radiator. I've actually got a pod filter on order... but i'm going to be making a custom airbox and cold air intake for it, and while i'll gain tiny power (if at all) the noise and the ability to make my own larger intake setup, which *may* actually provide some gains (ie. the air feed provides the gains, not the filter).

[em]

what is derestircting the airbox? what do you actually do?

What do you actually do? derestricted the airflow to the filter.
You take out the pipes that are connected to the current air box and derestricted them by running a pipe straight from the front of the car to the box. I have never done it but I watched Mr A and GOZOFF do it to Euro-Stylin’s car.

Can someone post a pic of what their car looks like with a derestricted air filter.

People mainly do it so that the air is cooler and the filter has higher sucking capacity I think???

[DoomTrooper]

yeh exactly right em
i've done it to mine, i made myself a new pipe out of some PVC and used some bends that i bought from bunnings to bend it, then i painted it black, glued it together and cable tied it in subtley, i got my 2 inch cat back twin 2' chrome tips at north shore performance exhausts in hunter st hornsby, cost $350, is pretty damn loud but doesn't have a cannon

[dan_kind]

Pod filter has always worked for me... There is enough air flow under the bonnet of the Barina to move hot air away, my intake temperatures according to a thermocouple on the pod, and the OBD computer is one or two degrees above ambient ..

The MAF reports higher air flow at full throttle as well, i removed the air box all together as it is a total waste of time, kept the original 'pipe' from the front of the vehicle.

I have tested it back to back with the standard and after market panel filter in the box, the box reporting higher than ambient air temperatures all of the time, and once they warm up at the lights (near 80c) they dont cool down, where as the pod will get warm (70c) but cool down as soon as there is air flow...

this only goes for beep beep being as though the astra doesnt seem to have the same air flow characteristics under the bonnet.

police have pulled me over, indicated that there was a problem with the pod as it creates noise pollution and is a fire hazard. My response was that i dont drive at full throttle (obviously) around town or in the burbs, so the sound isnt a problem, and as for fire, well, if there is going to be backfire through the intake manifold, it will cause a fire regardless of what intake system there is.

He let me drive off?

destricting air boxes can cause some pretty strange flow characteristics, i have seen a few examples of destricted air boxes on flow benches..

[break]

dan_kind, so your not using and heat shielding at all... and the standard intake pipe that runs from the grill down to where the lower half of the airbox normally is?

How is your low down torque after the car start sucking in the hot air in stop/start situations?

[dan_kind]

As mentioned, i have tested both setups with a thermocouple and using digimoto via scantool's obd reader, and the pod (even if it does get to 70 odd) cools down immediately, the box when it gets hot (in a bout the same time) does not cool down as quickly...

and what is a heat sheild going to do? Its not like its a big block chev or a super/turbo charged monster, the Z18XE is hardly going to radiate that much heat.. the heat 'shield' is going to end up reducing the under bonnet flow characteristics (that i can only think are part of the design)...

there thermocouples, one ON pod on ON air intake (at front of vehicle, behind bumper) and one near brake master cylinder gives a good idea of where the heat is going once moving.

more than happy to demonstrate the temperature differences...specifically what occurs at high speed...