induction kit

[innes]

is it worth me putting an induction kit on my auto 325i, if so cheapest way of doing this and what benefits willi gain?

cheers guys

[M5pilot]

Can give you some feedback on this based on my own experience and that of customers.

K&N - makes loud noise and loses you bottom end torque

BMC CDA - No difference felt until about 4000rpm +, makes a fantastic noise though!

ITG Kit - definate difference felt in the midrange and over. Makes subtle induction noise.

Pipercross Viper - no difference anywhere and costs £250!

[massive]

Drill a 30-35mm diameter hole in your standard airbox. Happy Days!!

[Rosc0PColtrane]

Induction kits certainly can make a difference, however you will need to isolate the filetr from the heated air from the engine as this is less dense and will make the induction kit worse than the standard method of induction.

Personally, I had a K&N on mine, the engine heat caused the cheap universal air flow meter bracket to become brittle and snap. K&N were impossible to deal with and refused to replace it (the bracket, I had the filter still, wedged in my engine bay) without me providing a receipt for the item. I didn't notice a difference in performance when it snapped off.

So I replaced it with a pipercross unit. Made out of machined aluminium, it felt a better quality and being machined aluminium, felt more like a bespoke item, instead of K&N's universal "guess" at what would fit. Noticed a difference in performace when fitted and a lovely induction growl. Am going to fabricate a piece to isolate it from the engine heat at some point... Was a picture of a zone car with a very professional looking cover on floating about somewhere..

Hope it helps..

[innes]

'Drill a 30-35mm diameter hole in your standard airbox. Happy Days!!'

seriously??? got a pic to show me?

[M5pilot]

Heat soak is not an issue unessl you want full power in in town driving conditions.

I've taken readings whilst driving the car with one probe insude the stock airbox and one outside it. When the car is stationary there is a big difference between the air temp inside and outside the box. It takes about 2-3 minuites for this differnce to build to its peak though which is about 37 degree difference.

However, once the car starts moving there is no difference at all. Literally takes a few seconds for the air temp difference to become zero.

[cliffybabe]

After reading this thread i bought the itg cone filter form taxidriver today

Ill let ya know what i think

Thanks

Neil

[massive]

'Drill a 30-35mm diameter hole in your standard airbox. Happy Days!!'

seriously??? got a pic to show me?

EDIT: Double Post

[massive]

'Drill a 30-35mm diameter hole in your standard airbox. Happy Days!!'

seriously??? got a pic to show me?

Yeah a few E30's on here have drilled airboxes - I'll take a piccy of mine when I can, and add to this thread.

[taxidriver]

Ive had both in the past, drilled airbox and itg

trust me, drilling the airbox adds nothing to the power, just makes more noise!

ITG is definately the one to go for, well worth it, adds to midrange and top end grunt

[M5pilot]

Drilling the air box was actually shown to lose power on a dyno run. Why? Because you don't have a smooth flow of air.

[ric325i]

i was told the main feature of the standard air bow is the directional pipe before the air flow meter!

so i have used a large cone filter on a 4inch tube for directional air into the box, with the big cone allowing lots more air into the flow meter.

the next thing to do is just get more air to the filter. either make some sort of panel to block the heat from the engine (seen this done very well on a subaru legacy turbo with a curved piece of carbon fibre sheet) and or a tube to direct more fresh, cold air to the filter.

performance and sound. best of both.

[delphini]

could you please be more specific on the hole and what location to drill at ???
i understand on a dyno it might not jjive out but if one is planning an intake kit or a K&N setup at a later date i see no harm in attempting this low cost temporary adjustment.

[M5pilot]

notice inside the Airbox there is a trumpet (which some people remove). This is for directing the air and creating a smooth flow.

The K&N/Pipercross designs do away with this trumpet and you inevitably lose torque.

The ITG Maxogen filters all come with an inbuilt trumpet for this very reason.

I will get some foto's up to illustrate.

[bottlecapE30]

Heat soak is not an issue unessl you want full power in in town driving conditions.

I've taken readings whilst driving the car with one probe insude the stock airbox and one outside it. When the car is stationary there is a big difference between the air temp inside and outside the box. It takes about 2-3 minuites for this differnce to build to its peak though which is about 37 degree difference.

However, once the car starts moving there is no difference at all. Literally takes a few seconds for the air temp difference to become zero.

That is what i have been saying....at last some tech to back it up

[Rosc0PColtrane]

Heat soak is not an issue unessl you want full power in in town driving conditions.

I've taken readings whilst driving the car with one probe insude the stock airbox and one outside it. When the car is stationary there is a big difference between the air temp inside and outside the box. It takes about 2-3 minuites for this differnce to build to its peak though which is about 37 degree difference.

However, once the car starts moving there is no difference at all. Literally takes a few seconds for the air temp difference to become zero.

That is what i have been saying....at last some tech to back it up

Which is great for standard set ups, but for those who chose to go with an aftermarket option, surely the heat would become an issue without the protection the box offers?

Also when I took mine off, there was a plastic piece which looked like a "kissing gate" type arrangement, looked highly restrictive.

[M5pilot]

Leave that plastic piece where it is, its there to direct the airflow. Remove it and you'll lose power and torque.