Induction Kits (sorry!)

Mint · Post by **Mint** » Tue Nov 07, 2006 10:46 am

Hello to all, hope ur all doin gd.

I recently bought an induction kit for the polo, thinking it was one which sat on the top of the throttle body - it didnt. so heres an image of the way i set it up:

as you can see i still have the original airbox on. the problem with this set up is that i dont get any induction sounds whatsoever, it sounds no different than having the airbox alone on. so now im thinking that i should swap my airbox for a K&N and have both air filters fitted at the same time? alternatively, is there anyway of readjusting the filter to get an induction sound?

cheers peeps.

dragon_green · Post by **dragon_green** » Tue Nov 07, 2006 11:22 am

Go for 2 air filters, that way you can half the amount of air getting to the engine....

mc_iver_9n · Post by **mc_iver_9n** » Tue Nov 07, 2006 11:23 am

The standard airbox will still be restricting the air, so you need to remove it out of the equation for the induction kit to have effect and make the sound more beefy. Thats what it seems like to me. Please correct me if im wrong

gina · Post by **gina** » Tue Nov 07, 2006 3:01 pm

Shouldn't the K&N be a replacement for the original, not an extra!

PeteJ · Post by **PeteJ** » Tue Nov 07, 2006 5:05 pm

chuck the airbox, either buy some suitable hosing and jubilee clip it directly to the TB, or go and have a look at a skoda felicia in a junkyard they have similar engines and i do beleive the 1.6 model has a perfect fit bit of hosing.

btw green cotton air filter are designed to sit on top of the filter.

kipper · Post by **kipper** » Tue Nov 07, 2006 6:34 pm

as far as im aware u have to remove the standard air filter.
a guy i know put one on his clio same as urs leaving the standard air filter on and i told him it replaces the filter.

nows hes got a polo and wants to get an induction kit for it.

i got an induction kit for my car and i had to take the standard air filter of and put the new one straight on the throttle body thingy. as i got the facelift model i had to get some small breather filters for the breather pipes now it sounds beefy and doesnt get in the way of n e thing.

R1CH · Post by **R1CH** » Tue Nov 07, 2006 7:24 pm

The airbox needs to come off to fit a cone filter.Im not even sure how youve fitted that looking a that pic

R1CH · Post by **R1CH** » Tue Nov 07, 2006 7:27 pm

sh!t,,,,ive just worked out what youve done,,,youve put the filter on the end of your o/e cold air feed,,,id sort it pretty quick,,,,,,,take the airbox and get summat thatll let you fit it on the TB.

dj_milky · Post by **dj_milky** » Tue Nov 07, 2006 8:21 pm

get a 90degree bit or piping and get the big box off, my induction kit did sit ontop untill i got the steel pipe

carmadaaron · Post by **carmadaaron** » Tue Nov 07, 2006 9:01 pm

yep, its good the way that dj_milky has it set up.

the original filter is the big restrictor.. air has to go a long way (twists and turns) before it reaches the engine. Take the old one off!

Mint · Post by **Mint** » Wed Nov 08, 2006 11:50 am

Cheers for the replies.

Dj milky, i was also thinking of connecting it the way you have done it. the reason i havent put it directly on top of the throttle body is that the cone is too large to fit on top, and has to be angled slightly for the bonnet to close properly. this cant be good for airflow etc. what have you put on the end of the breather pipe milky? and how to i go about getting an attachment at the end of the piping which fits the throttle body exactly? also do you get a good induction sound with the filter fitted this way ro does it have to sit on top of the throttle body?

thanks again.

LeMeph · Post by **LeMeph** » Wed Nov 08, 2006 12:08 pm

First thing ill say about the air filter is i dont have one. So that makes me an expert. Oh wait no it doesnt. But i still have somthing valid to say.

Basically think about the mechanics behind the air flow. The setup using the steel pipe and samco hose looks very pretty but its gonna (by my theory atleast) restrict your airflow somewhat. Right to explain this is gonna eb complicated and my written english si worse then my spoken lol so abre with me.

You want air to get into your throttle body as quickly as possible. You want it to be able tos uck straight in, you also want this air to eb colder and thusly denser. Now the problem with the steel pipe and samco set up seen above is that the air isnt going to flow up the pipe unless its sucked up the pipe. Fresh air firstly has to force its way through the filter (which it isnt likely to do as the particles would most likely find it easier to flow around the filter) which is not good, as it has to force tis way through this means there will be less fresh air in the pipe. The second rpoblem i see with this set up is that its too close to the engine with no heat shielding. When yuor moving the air obviosuly isnt going to be magnicantly hot when your driving so you will get some cooler air running around, but when your idling thats going to be sitting there pulling in lots of warm air. Probably not a good thing though i dont know im no expert lol.

The ideal filter by my head is one that is, like the standard, as clsoe to the throttle body as possible. thats right theres a reason VW put it there and theres a reason most polos sound like theyve already got filters fitted! I know mine sucks like a beach, and its good. Standard = good. But lie i was saying. A filter that is contained within a heat proof box as close to the throttle body is ideal. Now you want a cold air feed leading into that filter with as straight a route as possible. This is because the air will, as you pick up speed that is, jam its way up the filter then theoretically the flow would come to a near stop at the filter itself. This means youve got loadsa fresh, cool unfiltered air in the pipe being packed and condensed as you go along. Obviously the better option as when your car wants it its there, and its good. All good.

EDIT: (just realised there is a heat shield on the samco pipe set up, which is good but the point about flow still remains i think)

Think thats about right. Anyone find any flaws in that?

Chris,

dragon_green · Post by **dragon_green** » Wed Nov 08, 2006 5:35 pm

LeMeph, you're essentially right.

Remember that as a cylinder moves to it's intake phase, the expansion of the cylinder acts as a vacumn pump, i.e. it actively sucks air into the cylinder. (Hence when you calculate the theoretical power of an engine, you must allow for losses which are inherent in the engine design, eg pumping losses)

Whether it's better to have the filter closer to the TB or further away, I'm not sure. By intuition, I imagine closer to the throttle body would be better. However you must consider the physical constraints (i.e. packaging it) of the engine bay.

For sure though, it's best to feed air from the grill into the TB (via a filter at some point, obviously). You need to do this to get cold (i.e. denser) air into the engine. Denser air helps get more power. Just lobbing a filter on top of the throttle body without a cold air feed means you will pick up air that's just been through the radiator (therefore warmed up) and then over the engine (warmed up again); which will be disadvantageous when compared to a colder air feed.

Hope this provides a bit more information.

dj_milky · Post by **dj_milky** » Wed Nov 08, 2006 7:14 pm

my breather pipe is connected to the air filter itself, the k&n comes with plug sorta thing to put hose on and and u can see got a see through hose connected, i used to have the induction kit onto of the throatle body but though it wasny gettin enough cold air that why was moved to grill. i drive a one litre so end of the day its not a rocket and mainly is show car so doesny really bother me. anything u do to ur car thats not factory standard is going to f**k it up in the long run

PeteJ · Post by **PeteJ** » Wed Nov 08, 2006 8:41 pm

anything? not if its done properly.
off topic but whats with the hose pipe running along side your air piping lol?