# modifying an induction kit



## hoikey (Mar 9, 2011)

I currently have an induction kit on my car and am thinking of ways to improve it using DIY. So on the basis that having a large volume of filtered air aids throttle response then would adding a box after my filter to effectivly hold a large amount of filtered air help improve throttle response?


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## 182_Blue (Oct 25, 2005)

Play with it as much as you like but i doubt you will feel or get any difference in the car, IMO your time/money would be better spent elsewhere as Induction kits rarely add anything to a car other than aesthetics.


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## tones61 (Aug 21, 2011)

inducting cold air is more conducive to power,:driver:


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## Bod42 (Jun 4, 2009)

The cone type Induction kit loose power 9.9/10.


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## Shinyvec (Feb 12, 2010)

Just try to get as much cold air to the filter as possible and take measures to avoid heat from the engine being drawn in. Original Airbox's are quite good at keeping hot air out and just replacing the standard OE Panel Filter with a K&N etc Panel Filter can give far better results than a Induction Kit except the induction note.


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## hoikey (Mar 9, 2011)

Bod42 said:


> The cone type Induction kit loose power 9.9/10.


Id be interesting to see some evidence of that.

Mine has gained power from the inducion kit.
I dont suffer too much with heat soak and usually have a couple of degrees above ambient as my intake temps


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## Jem (Aug 10, 2007)

hoikey said:


> Mine has gained power from the inducion kit.


How do you know?

I've found cone filters normally make little difference to power, sometimes producing less power than a standard setup.


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## Fiesta-125 (Mar 18, 2012)

TBH the gains of a induction kit rarely outweigh the disadvantages, you're better getting a CAI. Theres no point adding a box because it's a constant through draft if you get me just a larger space and if you engine wants that air it will suck it through. The only benefit from adding a box will be one that has compressed the air, so you get say 0.2 Cubic metres of air inside a box 0.1 cubic metres capacity, constantly, this way you have twice the amount of air available to your engine, however in simplistic terms this is just how a forced induction engine works so defeats the object, if you're after more power you have three options

1. Get a bigger engine
2. Use forced induction(Turbo/Supercharger[Twin Charge])
3. Either of the above


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## hoikey (Mar 9, 2011)

Jem said:


> How do you know?
> 
> I've found cone filters normally make little difference to power, sometimes producing less power than a standard setup.


Dyno.

And i know forced induction or itb isthe way to go but i cant afford that atm so thought i could make a bit of a stainless box up at work to put after the filter


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## Fiesta-125 (Mar 18, 2012)

hoikey said:


> Dyno.
> 
> And i know forced induction or itb isthe way to go but i cant afford that atm so thought i could make a bit of a stainless box up at work to put after the filter


WHat engine is it? 1.5 vvti?

So you want to make a Plenum chamber? However non pressuurised, no point imo


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## hoikey (Mar 9, 2011)

1.6vvti


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## Fiesta-125 (Mar 18, 2012)

hoikey said:


> 1.6vvti


If you want more power, get a decent hi flow manifold and cat, or even decat followed by a good cat back system. You gain a few extra and will feel the vvt much more, sound nicer too. Ensure you have a good air flow system dont worry about a little box and give it a good service. Modifying small engines is worthless because the amount you spend doesn't really correlate to the amount of power gains acehived.

Hope i've helped and not been to criticizing. :thumb::thumb::thumb:


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## hoikey (Mar 9, 2011)

Exhuast is done with second cat out. Need a mani for it soon. 

I know its only a small not very powerful engine but it handles great and just needs a few more ponies.

For a few grand it can be bumped to 220bhp but as im moving in soon thats not an option


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## Bod42 (Jun 4, 2009)

hoikey said:


> Id be interesting to see some evidence of that.
> 
> Mine has gained power from the inducion kit.
> I dont suffer too much with heat soak and usually have a couple of degrees above ambient as my intake temps


Engine Bay Temperatures during a Dyno are lower than when driving a car normally or racing. I said Filter not induction kit, which makes a difference.

Did you run a Dyno, put the new filter on and then run again right after one another.

Filters suffer really badly from heat soak and its simple science that cold air is denser than warm air. More air + More fuel = more power.

If you go for an induction kit go fully enclosed Carbon Fibre with direct cold air feed as CF doesnt conduct heat as well.

Check out google for evidence, theres loads.


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## B17BLG (Jun 26, 2012)

Bod42 said:


> Engine Bay Temperatures during a Dyno are lower than when driving a car normally or racing. I said Filter not induction kit. which makes a difference.
> 
> Did you run a Dyno, put the new filter on and then run again right after one another.
> 
> ...


incoorect, the fans on dynos do not provide the same airflow as out on the open roads!

Heat soak is only a matter for n/a engines which in this case it is.

If you have an induction kit fitted leave your air feed in and blow cool air into the filter!

Uploaded via my test iSpamphone on Vodafone on Tapatalk2


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## Jem (Aug 10, 2007)

I swear my RX-8 was faster after I removed the K&N panel filter, decat and full stainless system just before I sold it.


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## hoikey (Mar 9, 2011)

As i say though. My intake temperatures dont get very high apart from when im not moving. Heat soak isnt an issue at all on the car


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## Shiny (Apr 23, 2007)

CAI :argie:Get that filter in the wing :thumb:


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## possul (Nov 14, 2008)

Modified air box with panel filter.
Unless its a sealed induction kit
Warm air from an engine bay will not increase power imo, n
Always used panel filters in my cars


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## possul (Nov 14, 2008)

Jem said:


> I swear my RX-8 was faster after I removed the K&N panel filter, decat and full stainless system just before I sold it.


I've driven a couple of rx8's with induction kits and exhaust, they had even less torque than before, probs to lack of back pressure by exhaust system


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## hoikey (Mar 9, 2011)

possul said:


> Modified air box with panel filter.
> Unless its a sealed induction kit
> Warm air from an engine bay will not increase power imo, n
> Always used panel filters in my cars


Noone said warm air will increase power :S.

I DO NOT HAVE A PROBLEM WITH HEAT SOAK!!!!!!


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## nick.s (Dec 21, 2009)

Get some cold air feeds from the front bumper to the cone filter, would probably get a better flow of air to it, making it a smidge more effective up front


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## BoostJunky86 (Oct 25, 2012)

B17BLG said:


> incoorect, the fans on dynos do not provide the same airflow as out on the open roads!
> 
> Heat soak is only a matter for n/a engines which in this case it is.
> 
> ...


Heat is only a matter for N/A engines?

Unless I've read how you've written that, it's complete rubbish! Turbos produce ridiculous amounts of heat!

I couldn't comment on supercharges as I truthfully don't know. But being belt driven forced induction not being reliant on exhaust gases I wouldn't have thought they were to bad :dunno:


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## BoostJunky86 (Oct 25, 2012)

Adding air filters exhausts etc etc may get the odd few horses freed up but it's making more difference to the feel rather than actual power, 

Out of interest what extra power did it add?

I'm torn with the dyno temps. As once the cars warned up and say the first run I'd imagine the temps are good, but any after that the rolling roads are normally Warner than outside driving conditions. People forget Dynos are far from real life performance! Close but having your car live mapped would be better!!

Proof of this would be my first scooby, on rollers produced 261bhp and about 320ft/lb torque at 1.5 bar on the rollers,
Started driving home and saw 1.6 bar and could hear the turbo over boosting! 
Colder denser air on the road, actual load on the car etc,


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## BoostJunky86 (Oct 25, 2012)

Hoikey. 

Your best bet would be fit all the bits you want, exhaust air filter etc,

Air filter wise fit either panel or cone, just keep as much heat as possible away from it and allow it access to cold air it'll be fine! 

But once it's all fitted have the car mapped. As changing air filters etc on newer cars with intelligent(although annoying) ecu's are very good at stopping the car from releasing full potential as they are designed to run within strict parameters. 


That's just my thoughts. Although I could be wrong


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## TubbyTwo (Apr 14, 2011)

Box the filter and run cold air feeds into the box.

Simples.


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## Jem (Aug 10, 2007)

BoostJunky86 said:


> Heat is only a matter for N/A engines?
> 
> Unless I've read how you've written that, it's complete rubbish! Turbos produce ridiculous amounts of heat!


It's not complete rubbish at all. The intercooler makes intake temperatures at the filter largely irrelevant.


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## TubbyTwo (Apr 14, 2011)

Lets be honest no one fits an induction kit to an NA and expects a noticable increase, fit, run some cold feeds and enjoy the noise.

I had an K&N filter and hard pipe intake ont he Supra, have now swapped to the OEM airboxes and its far better to drive. Low down torque has improved as well.

Great for noise, but no noticable gains, despite what the makes tell you.


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## BoostJunky86 (Oct 25, 2012)

Jem said:


> It's not complete rubbish at all. The intercooler makes intake temperatures at the filter largely irrelevant.


If your serious about performance, why make the intercooler work harder? 
Colder temps at the air filter less work for the intercooler to reduce temps down or reduce temps even further, surely you want the temps hitting the combustion chamber to be as cold as physically possible?


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## BoostJunky86 (Oct 25, 2012)

TubbyTwo said:


> Lets be honest no one fits an induction kit to an NA and expects a noticable increase, fit, run some cold feeds and enjoy the noise.
> 
> I had an K&N filter and hard pipe intake ont he Supra, have now swapped to the OEM airboxes and its far better to drive. Low down torque has improved as well.
> 
> Great for noise, but no noticable gains, despite what the makes tell you.


Couldn't agree more


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## vroomtshh (Nov 23, 2009)

BoostJunky86 said:


> If your serious about performance, why make the intercooler work harder?
> Colder temps at the air filter less work for the intercooler to reduce temps down or reduce temps even further, surely you want the temps hitting the combustion chamber to be as cold as physically possible?


You think 10 degrees at the filter will matter once its been through a turbo at 900+ degrees?

Quantity of air is far more important than temperature on a turbo car, unless your working in F1 where every single .1 of an HP matters.


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## BoostJunky86 (Oct 25, 2012)

No I'm just saying for something as simple as "trying" where you can to keep temperatures as low as possible will help?! Every little bit helps surely? Why the hell would you try to do everything you can to make it perform its best, if your going to do a job might aswell do it right!

Anyway my original comment was temperatures aren't only an issue on N/A cars?!


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## TubbyTwo (Apr 14, 2011)

As long as it doesnt end up looking like this you will be fine:


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## BoostJunky86 (Oct 25, 2012)

Is that top one a focus?

Gotta love the zip ties lol


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## Jem (Aug 10, 2007)

BoostJunky86 said:


> If your serious about performance, why make the intercooler work harder?
> Colder temps at the air filter less work for the intercooler to reduce temps down or reduce temps even further, surely you want the temps hitting the combustion chamber to be as cold as physically possible?


Indeed, which is why I said 'largely irrelevant'.


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## msb (Dec 20, 2009)

I've had plenty of cars with induction kits and all made above manufacters figures when dynoed and were noticeably quicker on the road, biggest problem with induction kits usually is the person who's fitted them, poorly fitted ones with crap or no cold air feeds will obviously lose power!


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## TubbyTwo (Apr 14, 2011)

same here, and all moved the torque higher up the rev range. different story on a forced induction car, but on a little 1.5 for the sake of £70 and 5bhp i wouldnt bother.

Bearing in mind that an NA engine will only suck in as much air as it needs at any given RPM, no amount of ducting, cold air feeds or air rams are going to make much of a difference.

Has anyone actually measured the increase in WHEEL bhp before and after fitting an induction kit? Thats where it counts, flywheel bhp figure isnt an exact number (but it sounds great in the pub).

My MR2 turbo with ducting, and filter positioned right over the rear air intake for the engine bay made a whole 6hp gain over the stock boxes and lost some low down torque from removeing the stock system (with various air tanks). For over £100 is it really worth it? sure it sounded great, but real world in my experience hasn't made any difference.

panel filter in the stock box and leave it be.


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## B17BLG (Jun 26, 2012)

BoostJunky86 said:


> Heat is only a matter for N/A engines?
> 
> Unless I've read how you've written that, it's complete rubbish! Turbos produce ridiculous amounts of heat!
> 
> I couldn't comment on supercharges as I truthfully don't know. But being belt driven forced induction not being reliant on exhaust gases I wouldn't have thought they were to bad :dunno:


Right, it's pretty simple in fairness. Engine temps are no way near as hot as a spinning turbo.

So you could have the coldest air feed on a turbo car but it still travels through a red hot turbo. After its through the turbo its down to the intercooler to cool the air and how effective that is.

Hence my comment N/A engines only suffer from heat soak.

Inlets temps on my cone filter are identical to with a airbox due the intercooler i have 

Hope this makes sense now


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## TubbyTwo (Apr 14, 2011)

Chargecooling is where its at


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## Bero (Mar 9, 2008)

Yes/no. You're effectively creating a plenum (iirc), it will help absorb the instantaneous air requirements of each cylinder as it's intake valve opens. This will have a limit of effectiveness tho and if your air sensor is upstream of your 'large volume tank' your A/F ratio if do funny things on throttle application/lift off (i think)


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## tones61 (Aug 21, 2011)

on my standard mk2 golf gti 8v,,,fitted k+n panel filter and drilled holes in lower airbox case,
back to back rolling road test gained 4bhp at wheels, :driver:


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## B17BLG (Jun 26, 2012)

tones61 said:


> on my standard mk2 golf gti 8v,,,fitted k+n panel filter and drilled holes in lower airbox case,
> back to back rolling road test gained 4bhp at wheels, :driver:


Not a bad gain at the wheels! More air available at the engines use i suppose


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## TRN Ent (Nov 16, 2008)

With my Mk1 MR2 the stock air intake was quite restrictive, so I stuck on an enclosed air filter with a tube down in front of the engine, it made a huge difference in sound, when the T-VIS kicked in you could really hear the change of tune.
Tom.


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## cbr6fs (Aug 15, 2011)

Problem here is people are talking in such generalisations that's it's pretty much pointless.

98% of CAI's and intake kits are a waste of time.

Add to that the fact that the vast vast majority of users do not clean or maintain their new filter and it starts getting to be a waste of money as well.


Intake kits do work better on some engines than others though.
On some like my MX5 the stock intake is extremely well designed so there is absolutely no gain to be had, in fact your likely to loose power.

Now add into that inconsistent Dyno figures and it really does start to get into the realms of BS.


The thing is, if your running 140bhp and you gain 4 bhp from a intake kit then not even Schumacer would notice that small a gain.
If your racing and challenging for the title then fair enough every bhp counts.

On the road though it's absolutely pointless.

It's also worth mentioning that BHP is also very limited in communicating across a cars power.
I can tune a car and gain say 10bhp at peak rpm, but i'll guarantee the car will lap faster if i can dial in more mid range.

Disagree?

Ok next time your driving on a pubic road add up how many seconds your at the last 5% before the redline, then calculate how that corresponds to the total driving time.
If your over 0.01% then either you need to stop driving like a **** on public roads or you need to trade in your 2CV for something with a bit more power.

What's more accurate for gauging a cars power is the "area under torque" or the total mass of the area under the torque curve throughout the entire rev range.
THIS is the only thing that tells the entire story.


As for the intercooled comment, again what a load of rubbish.
AGAIN it's to general to be of any use to anyone.
Some cars struggle with their stock intercooler size, others are well spec'd PLUS the colder the air in before the FI device the less the temperature delta.


My advice is:
If you want more power look elsewhere
If you want your car to sound faster then by all means go for it
If your bored and want to faff with the intake then it's your car your choice, but if your expecting to notice any difference your deluded or just plain wrong.

Don't get me wrong, we all faff about and do pointless stuff to or on our cars, i'm not saying it's a bad thing, just don't delude yourself that you will notice any difference.


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## tones61 (Aug 21, 2011)

generally known that anything less than 5bhp cannot be felt on the road,

similar to the feel between a cold day and hot day powerwise,:driver:


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## B17BLG (Jun 26, 2012)

cbr6fs said:


> Problem here is people are talking in such generalisations that's it's pretty much pointless.
> 
> 98% of CAI's and intake kits are a waste of time.
> 
> ...


Incorrect, You could have 5 degree air coming through the AFM and 15 degree, they both have to travel through the red hot turbo? Then your intercooler size or efficiency will affect the delta inlet temp!


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## cbr6fs (Aug 15, 2011)

tones61 said:


> generally known that anything less than 5bhp cannot be felt on the road,
> 
> similar to the feel between a cold day and hot day powerwise,:driver:


Again to general to be any use.

A 5bhp gain on a 2CV will will great, a 5bhp gain a GTR is nothing.



B17BLG said:


> Incorrect, You could have 5 degree air coming through the AFM and 15 degree, they both have to travel through the red hot turbo? Then your intercooler size or efficiency will affect the delta inlet temp!


Yes they will but the turbo will only heat the air a certain amount.
If you have a 5C intake temp and the turbo runs around 200C flat out then that's going to give you 205C.
If on the other hand you have 15C intake temp then that's going to give 215C.

The intake temp is the delta.

I'm not saying a CAI will negate a intercooler, BUT even in FI'd application the intake temp STILL makes a difference.


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## hoikey (Mar 9, 2011)

cbr6fs said:


> Again to general to be any use.
> 
> A 5bhp gain on a 2CV will will great, a 5bhp gain a GTR is nothing.
> 
> ...


That maths is completely wrong, if the turbo is 200 then the air will not get above this


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## cbr6fs (Aug 15, 2011)

hoikey said:


> That maths is completely wrong, if the turbo is 200 then the air will not get above this


Your opinion and your welcome to it :thumb:

I'm not going to say anymore as it's not really helping to op with all this offtopic chat.

All i will say is, do some reading up on air friction, compression and temperature :thumb:


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## Mark Chandler (Nov 7, 2011)

What an odd thread, some people know what they are saying while others are asserting a load of tosh.

A well designed OEM system will be better than a poor aftermarket fitment.

Cars need cool air to gain maximum performance, so duct from the outside if possible, most OEM,s will try and draw air from in front of the radiator, junk the standard box and put on a cone filter and you have the potential to draw in heated air, the ECU,s knock sensors will then retard the ignition to compensate and you lose power. 

Think of an engine as a pump, if you restrict the inlet you will waste power pulling fresh air in, by removing or lessening any restriction you will gain power when everything is optimised, this is why some race series the regulations call for inlet restrictors to pull down ultimate power gains, usually on turbo cars.

Intercoolers negate the need to worry about this.... What rubbish intercoolers introduce restriction, if you use and air to air intercooler then a fantastic one may be able to bring the temperature down to ambient, it can never achieve this although may do a very good job. The better it is cooling air then in general it will need to be larger so you are carrying more weight, also the air to be cooled will have to pass by more fins = more restriction so you have to waste power pushing it though. Go read Corky Bells book on forced induction.

To spin a turbo you may be taking up to 1/3 of the engines power to double the output at full chat, this will be drastically heating the air charge as you compress, so shove air at 50 degrees through an intercooler and it my come out 5 or 10 degrees above ambient. Put on a supercharger and you will also be pulling power to spin, it will also produce lots of heat compressing the air, on a vane supercharger the tips of the vanes go supersonic flat out! 

So plan what you are doing and you should see some gains in most cases as an OEM will probably draw in cold air, however to maintain noise levels will also probably be restrictive at some point.

Note, the water to air intercooler on my DB7 is rubbish, very small and cannot lose the heat generated at load as the water side heats up, on what you would expect to be a good system, 3.2 litre car producing 340bhp it is only good for a few seconds before it all starts to cook. OEM does not always mean it is any good, although nicely ducted to the front.


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## Bod42 (Jun 4, 2009)

B17BLG said:


> incoorect, the fans on dynos do not provide the same airflow as out on the open roads!
> 
> Heat soak is only a matter for n/a engines which in this case it is.
> 
> ...


I never mentioned air flow I am talking about engine bay temperature.

I agree that Dyno fans are not as good as the open road but on the dyno your doing a run that doesn't even last a few mins compared with fast driving racing which is prolonged periods. An engine bay will heat up no matter what during racing so op for a fully enclosed carbon fibre kit and im certain you would see zero results.

I have experienced the hotter engine bay 1st hand. After racing the car was so hot the manifold was glowing red and the engine bay temp was unreal. Never had anything glowing on a dyno


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## Maggi200 (Aug 21, 2009)

Don't monster sport Europe develop and make proper kits for your car? I'm sure their kits would be an improvement over anything you could make yourself


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## apmaman (Jun 8, 2010)

I done my college HND Engineering Systems graded unit on my car and induction kits...

Conclusion was that it did add extra bhp to my car, and lower the air intake temperatures throughout the rev range. I had a few designs on how the indction kit was layed out inside the engine bay.

I took readings via OBD2 port while the car was on a Dyno, average of 3 runs showed that the mk1 intake gained 5bhp but didnt reduce air intake temps. mk2 gave fractionally larger increases (half a bhp) but also lower air intake temperatures which is always good. Colder air = Denser = bigger bang!

OEM air intake set up..









Best pic of my "mk1" induction set up, filter is placed right up where the cold air feed from the bumper is, but the filter is located right beisde the turbo charger, so heat soak was an issue










"mk2 setup with flexy aluminium pipe"









Fibreglassed 









"mk2" intake









Since then I have gotten rid of the Pipercross filter for a fully carbon fibre race ITG Maxogen kit


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## hoikey (Mar 9, 2011)

maggi133 said:


> Don't monster sport Europe develop and make proper kits for your car? I'm sure their kits would be an improvement over anything you could make yourself


The mse intake is very very expensive


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## Edstrung (Apr 6, 2009)

One big difference, after having my K&N cone filter on my diesel for 75k miles, was cleaning it for the second time last night.

Got a bit bored, decided it wasn't as pink as it used to be so just used the cleaning kit I got at the same time (6/7 years ago), let it dry out, reapply oil and dab off excess and let that soak in a bit. Re-install cone and went for a drive. Much better 

Moral of the story, doesn't matter what filter/kit you have, the element must be cleaned every 10k or so for best effect. The K&N filters say they get better with time/use as the oil catches the particles, and the particles then trap more particles. While I'm sure thats right, when there is a complete layer of dirt/dust on the outside, air flow must be restricted


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