[sixpot]

I love the noise my 335i makes, but would like to be reminded it is turbocharged once in a while!
What is the best route for hearing a bit more spool-up noise, maybe even (dare I say it) a whoosh from the DV?
Any particular induction systems etc....?
Your opinions appreciated.

[superdrive320]

I think downpipes (especially catless) probably open the sound up a lot.

[Kerr]

More boost!

[doughboy]

Open type air filter kits are great for whooshy noise.

BMS DC (dual cone) intake kit is best VFM.

try http://www.juiceduptuning.co.uk/shop_intakes.asp

Give neil a shout there, good bloke.

[zltm089]

I think the Gruppe M intake should give you a nice sound....all I know is that, its bloody expensive!...

[kaishang]

Replace the OEM engine with a gas turbine.

[Mike in Hampshire]

Originally Posted by doughboy

Open type air filter kits are great for whooshy noise.
BMS DC (dual cone) intake kit is best VFM.
try http://www.juiceduptuning.co.uk/shop_intakes.asp
Give neil a shout there, good bloke.

This. For less than £100 you'll get a lovely intake whoosh, as doughboy says; fitting is pretty simple too. Recommended. Also easily reversible if you need to return to stock.

Mike.

[phil200tdi]

Originally Posted by superdrive320

I think downpipes (especially catless) probably open the sound up a lot.

Yep. Big time...

[DavS1]

Note your standard airbox will be best for performance, but a cone filter will give you the most noise, whilst sooking in warm/hot air and slowing your car down

[seanblee]

I agree for an NA car, but it's not really noticeable on a turbo car - an extra couple of degrees at the start is peanuts compared to the heat gained as the air passes through the turbo... The intercooler will knock the temperature back to more or less the same by the time it gets to the cylinder anyway.

[DavS1]

absolute bollocks.

it's by far more important on a turbocharged car, for the rise in temperature delivered by compressed air. your intercooler wont be 100% efficient...the cooler the air going in, the cooler it will come out the turbo and the cooler it will be going through the IC. as a rule of thumb, 1degree c is equal to 1bhp.

Why do you think BMW design cold air feeds on their intake systems if "the intercooler will cool it back down anyway"

trust me, I work on a dyno all day, rolling roading, testing intercoolers, turbo's and mapping cars.

[seanblee]

How polite. I completely agree that cold dense air is better than hot sparse air, but I don't believe the change from the stock box to a DCI setup is really going to make a noticeable difference to performance purely because of the change in the charge temperature.

What do you reckon the temperature difference is going to be between the stock setup and the DCI once the car is moving? I'd be surprised if it's more than a few degrees given the amount of air passing through the grille into the engine bay. So, supposing 1 degree C makes a 1bhp difference, 1 degree C at the inlet translates to 1 degree C at the cylinder (which seems unlikely) and the stock intake isn't saturated at full load and restricting airflow - that means 5 degree hotter air will make 5bhp less. That's much less than the difference between regular and premium unleaded, for instance, so I don't really think is anything to worry about. Obviously my opinion, take it or leave it (or call it 'absolute bollocks').

[DavS1]

Sorry, I just felt very strongly about you're reply

well having tested a car with std cone and stock airbox, on a mild day the difference was 16c, tested on the rolling road, with a pretty huge fan so say for talking sake it was 10c on the road, thats 10 horses...

wether you care about those 10 horses or not, is another matter.

the other thing i'd throw into the equation is, cone filters fuck airflow meters - fact, it's the oil they are coated in coupled with poor filtration, IMO a loss of power, and potentially fucked airflow meter just completely rule it out for me.

[JJD]

Originally Posted by DavS1

absolute bollocks.
trust me, I work on a dyno all day, rolling roading, testing intercoolers, turbo's and mapping cars.

DavS1 I'm thinking of having my car dyno'd sometime soon, which rolling road do you work at?

[DavS1]

AVA down beside the airport in Glasgow mate

[onebadmofo]

All jokes aside the loudest thing I did on intake side was Vishnu charge pipe. I had Forge DV, intercooler and intake but the most difference was with the CP.

[doughboy]

Originally Posted by DavS1

Sorry, I just felt very strongly about you're reply

well having tested a car with std cone and stock airbox, on a mild day the difference was 16c, tested on the rolling road, with a pretty huge fan so say for talking sake it was 10c on the road, thats 10 horses...

wether you care about those 10 horses or not, is another matter.

the other thing i'd throw into the equation is, cone filters fuck airflow meters - fact, it's the oil they are coated in coupled with poor filtration, IMO a loss of power, and potentially fucked airflow meter just completely rule it out for me.

DavS1,

I think the theory is right, but it doesn't take into account the fact that with open cones the compressor has work less hard to draw in the air, so there is a lower pressure increase across it, thus the air is heated LESS as it is compressed.

I'm sure the US forum has various N54 dyno graphs showing actual manifold air temp being the same or lower with open cones even with higher atmosphere intake temp due to the above.

It's also worse on a dyno as the fans only simulate 30mph road speed at max, out on the open road the engine bay is filled with cooler air which no dyno cell fans could ever match.

My 335i was quicker at the top end with open cones, it pulled right to 6.5k, picking up at 5.5k where the standard airbox starts to make the car a bit wheezy.

PS: Re MAF issues, N54's are not mass air flow contolled, they have no MAF.

[Mike in Hampshire]

Originally Posted by DavS1

Note your standard airbox will be best for performance, but a cone filter will give you the most noise, whilst sooking in warm/hot air and slowing your car down

DavS1, this is not really comparing like with like, is it?

• The DCI cone is less restrictive than the factory airbox, so the flow levels differ, as Doughboy points out
• The DCI is made of different material than the OEM paper filter
• Chances are that folks running a DCI will be remapped to higher boost levels than stock, and may well have upgraded their intercooler too - the point being that the intercooler on a tuned car may mitigate any difference in intake temperatures inside the engine bay

I see dyno charts (on the US section) that totally contradict your assertion here, although some that support it too! Perhaps there are just too many variables here to make sweeping statements?

Bottom line for me is that the DCI costs very little, and makes a lovely noise, to my ears at least. Performance is probably little different from stock airbox in everyday use.

Mike.

[Boz335i]

I have the BMS dual cones and notice the car is more responsive.

Also, the noise sounds a bit like a tornado in the glove box when you push the loud pedal. It will put a smile on your face

[doughboy]

Ha! it does indeed.

Just watch you don't open the glovebox under full throttle, or else passengers / small children might get sucked in....

[DavS1]

The fan we use is probably nothing like the fan's you regularly see on a rolling road setup, it's probably more close to a 60mph wind simulation!

when testing std airbox against cone filter, the car had the bonnet open, we then fitted a seperate cold air feed enclosing the cone filter and the difference between bonnet up/normal fan on full speed and bonnet up/sepperate cold air feed and RR fan on full the difference was 16bhp....

I realise i'm not going to convince the masses, but having saw the difference with my own eyes having tested hundreds of cars rather than just theorized, I know for sure what works and what doesnt.

take the EP3 civic typeR (yes non-turbo but still same theory)...pre-facelift with std airbox car's make 9bhp less than post-facelift cars, and the only difference with the two engine wise is the post-facelift car has a piece of plastic that take a cold air feed from infront of the radiator, whereas the pre-facelift cars suck warmer air from behind the rad.

Anyway, I just thought i'd point out my findings with cone filters and why I wouldnt use one over a standard airbox

[doughboy]

Fair play mate, I think the gains are minimal if any, but it definitely freed up the top end on my car. I took it off because the noise put me off initially but when I did it felt like a pillow had been stuffed in the intake!
But I've bought a used on of these now, which has a heat shield and still gets a part feed off the standard cold air feed duct.

Worth a read http://www.n54tech.com/forums/showth...dci+iat+graphs

Re RR fans, the Car Planet Racing DynoDynamics 4WD 1000bhp dyno cell I last used has 2 giant fan modules in front and a full wall of extraction behind (they build and run 1000bhp+ Time Attack Evo's), fans on full was monstrous, almost blew your ear-defenders off and made more noise than the car, but the operator said it was still only equivalent to a 30mph road speed as far as the engine bay was concerned.