[The_Bear_Yid]

The 'Dave F' kits are/were popular on E36's. The kit looks like yours but with a heat shield an the results always seemed good.

I think a re-seller of JB4 did a test on open filters (with heat shields I think) and showed the was no loss of power due to hear soak I think. I'll have a look.

It may feel different to drive. Sometimes what you gain at the top, you lost at the bottom.

Lastly, you may need a remap for that mod or to get the best gains from it. Your car would have been mapped to your previous spec and you've just changed a variant.

[NJ 1161]

Originally Posted by DavS1

My bet's are (if you are feeling a lack in power) that it's definately heat related...1degree celcius is equel to 1bhp!

BMW probably spent a few thousand designing that airbox so it worked, it would have had a cold air feed as standard, I doubt there will be any way it can be improved upon UNLESS it was designed to restrict power, so that it didn't make as much as the model above perhaps? but I doubt it if im honest.
easiest way to test is refit standard box and see what you think!

Is that bit about 1bhp & 1 degree a joke? I read somewhere that diesels and turbos didn't suffer as much in terms of the temperature of the air given the turbo set up and the temp they already run at? I appreciate with a traditional naturally aspirated set up the cooler the temps the more the power.

Now, a couple of people are mentioning the remap and differing air amounts.

Surely, the air flow meter would adjust fuel/ air ratio making this irrelevant.

The remap was a 'evolve' @ Luton one, which is not custom, just a generic upload, so pretty sure filters would be irrelevant. Might mail Imran and ask ?

May refit air box to compare and also build heat shield as well. Presumably shielding the engine side would suffice ?

[mobilejo]

The remap you already have will be fine if it's just a new filter you have. The ECU sees the extra airflow and adjusts accordingly, that's why its not running lean.

If the car needed a remap every time there was more air coming in, you'd need one when you change your dirty OEM filter for a fresh one!

[dxb335d]

I do think it will draw hot air in, personally.

On a motorway it's no issue.

[Statler]

Just reading through and had a thought, may be wrong, but surely all the turbo'd cars run air-air intercoolers to reduce the temperature of the inlet charge to an acceptable level?

Admittedly if you're starting with a higher temp then it might not get to down to the right level, but it's certainly not going to be as high as an open normally aspirated engine that the DaveF/CAI kits were designed for.

On the dirty filter front, my old e36 318iS always benefitted from having the battery disconnected when the air filter changed. The car had the ability to learn and adjust to the airflow available. Resetting the ECU remove the custom part and improved the drive no end...

Maybe the newer tech doesn't do this but I'm look at 40k out of an original filter if I go by BMW service intervals. Can the car go that length without adjusting to the decreased airflow from the dirty filter?

[NJ 1161]

Seems that some have strong views that I could be down on low end but some not!

Well regardless, I've decided I like the noise, and fearing maybe I'm just imagining the loss of power. I will change the air box back to compare at a later stage, but for now think I may build a heat shield.

Drove it today and I like the whoosh/ pshhhh ( I know some won't) but the bit I love is the rumble. It sounds like a v8 burbling at low revs. Difficult to describe but sounds great!

So, a heat shield. My initial thoughts were aluminium, but now I'm thinking 3-4mm plastic similar to the orig air box. Being new to this heat shield building thing anyone got any thoughts/ guidance. I'm thinking of putting the extra pipe ( using original pipe and cutting) from the centre vents at the front of the bonnet to vent air into the box at speed and putting a pipe from the front rhd fog to feed air direct from the bottom.

I figure two sides on the shield to protect from turbos and back, should suffice basically an upside down 'L' or a '7' but straighter, as you look from the front?

[dxb335d]

Where are you based mate?

[NJ 1161]

Just outside Ipswich, suffolk.

(oh, and will try and get a thread up sometime soon, just need some decent pics)

[dxb335d]

My office is in Ipswich mate. I live near Cambs though.


We should hook up.

Does your car have genuine M3 panels?

[NJ 1161]

Sounds good. I Work in Stevenage so drive your way every day but not in the Bm.

Where do you work?

Some genuine. Would of done all oem if I had done conversion and considering changing some bits, but may just be my OCD as all looks good!

[DavS1]

No 1c does equal 1bhp! I work with rolling roads a lot in my job and monitor temp's of all sorts of cars, petrol, diesel, turbo, supercharged, N/A. It matters a huge amount on boosted engines as the temps are so much hotter it's more important to bring them down to ambient. If you start with a hotter inlet temp it's harder to bring it down to ambient so will be worse entering the throtle than it would be if you had a cooler inlet temp to start with.
Often find as well aftermarket IC's aren't as good as OEM IC's even if they are bigger in size (a lot of OEM IC's have V.good cores as they are usually limited for space so make the most of it!).

[NJ 1161]

So, 1 degree equals 1 hp. It feels very hot under my bonnet after a good run, so that's a worry.

Best try this heat shield. Do you think the heat shield will work as well as the original set up in maintaining ambient temp?

Anyone any views on best material to make the heat shield of of?

[DavS1]

Tbh I doubt it, as said before the E92's under bonnet is well sealed to keep heat in so the under bonnet air will be hot regardless, it might help but won't ever be as good as std airbox as it is fully enclosed and has it's own cold air feed from infront of the rad. You just need to look at the effort to get cold air to realise it has to be worthwhile.

[NJ 1161]

Originally Posted by DavS1

Tbh I doubt it, as said before the E92's under bonnet is well sealed to keep heat in so the under bonnet air will be hot regardless, it might help but won't ever be as good as std airbox as it is fully enclosed and has it's own cold air feed from infront of the rad. You just need to look at the effort to get cold air to realise it has to be worthwhile.

I've considered the cold air feed from the centre vent and decided that by cutting the original feed pipe in half I can pipe this into the 'to be sealed' are of the heat shield, thus keeping this feed of air.

Anyone got any opinions on best easily available, most effective, easy to shape, material to build shield from?

[e90-dave]

What do you really really expect to get when you strap that little halfords filter on to your german engineered machine? Seriously? 5BHP? You would notice nothing thats for sure.

I havent had time to read all the posts but I noticed 1 or 2 people who have sense and have mentioned that all of the hot air in the bay will get sucked straight up in to your intake. I would suggest a heat shield, and it would need to be a decent designed one too to.

Alternativly, you could save yourself the hassle of worrying about wether you have made 5BHP or lost 5BHP and buy a Gruppe M from a reputable tuning company and be done with it.

And fyi the Dave F was a very popular induction kit for the E36's, I have one on my 328i Sport and it is nothing like this halfords special. It is quite and oversized K&N filter with a well made heat shield, it gives you a good 10BHP (again its not day and night difference so you wont even notice it) I have this with an M50 inlet and BBTB's which helps.

Its all to do with Airflow thats measured in CFM, the stock box restricts a certain amount of airflow so using a cone like this will fre it up.

But it doesnt matter how big the cone is, or wether you had no cone on there at all the CFM flowing through the inlet can only be so much due to the diameter of the intake hose, Throttle bodys and inlet manifold etc.

So if you wanting more horses I would look in those places also.

Also, you talk about making your own heatshield using plastic. Have you ever thought of googling what materials reflect heat the best? Carbon fiber ring a bell for one?

And lastly, I dont want to sound patronising but comparing certain modifications over a range of different cars and engines really isnt the way to look at it, remember BMW really do know what they are doing (most of the time) I have dabbled with BMW lumps for years to come across that spending money on some parts really isnt worth it.

My 2 pence.

[NJ 1161]

Well, try reading the thread before commenting maybe?! (prick)

Just an experiment, looking for input as I've noted (some) people have an interest in this.

And, show me a gruppe m induction kit for the 335d and I will buy one?! (know your subject before commenting )

But, thanks for the input!

[e90-dave]

Originally Posted by NJ 1161

Well, try reading the thread before commenting maybe?! (prick)

Just an experiment, looking for input as I've noted (some) people have an interest in this.

And, show me a gruppe m induction kit for the 335d and I will buy one?! (know your subject before commenting )

But, thanks for the input!

Wow I get called a prick for trying to help.

I knew I should haven't tried to help someone with a 335D with M3 styling who gets a boner over the sound of a BOV.

[NJ 1161]

Trying to help? Which bit? Once again. Thanks for the input.

[Alex.Devol]

Originally Posted by NJ 1161

Drove it today and I like the whoosh/ pshhhh ( I know some won't) but the bit I love is the rumble. It sounds like a v8 burbling at low revs. Difficult to describe but sounds great!

I've been looking at doing something like this since i bought my 325d. I'm aware there will be no performance benefit to my car but am purely hoping to improve the engine sound. I've not had the car long and its the first 325 i've driven so i'm not sure if all 325 engines are like this but it has an annoying groaning sound when in low gear up to 2k revs. In start-stop city traffic its like there's a wheezing old man stowed in the engine bay.
I had been hoping for a few weeks now that the filter rumble you mentioned would be a good way of masking this noise?

I've looked at induction options but short of the 335 there doesn't look to be anything at all for the e92 diesels.. do you know if this is an option for my car?

ps. as some have already mentioned i'm also looking forward to a thread on your cosmetic mods if one goes up.

[NJ 1161]

Thought I'd update this. Ran filter for month and a half, no problems, but decided to re fit oem box just to see. Couldn't really tell any difference in terms of performance just very quiet again.

Ran like this but missed the burble, despite removing rear exhaust box the car is so so quiet.

So decided to re fit filter. Pondered making a heat shield, and when re fitting cone thought I may be able to use oem box and build on it.

So took some bits off and ended up with this. A semi heat shield! Also keeps original air feed in place.







So my thoughts now are get some 4mm aluminium or abs ( any hints appreciated) and use the base of the orig box and build up, using a rubber seal at the top. Looks fairly easy. Filter will move to middle if take a little nibble out if bottom part.

Ive also found a k&n filter for a Audi 4.2v8 ( should handle enough bhp) with a 92mm neck ( normal filter have 100mm neck and are a tad big, 92mm is exact for 335d) for £45 delivered so going to swop my filter. Not sure if this makes any difference but I took objection to it being called a halfauds filter!,,

It's not, it's a simota ( no I havn't heard of them either).

So, that's the plan. Car sounds great again. I know I'm not getting massive power gains but it keeps me out of mischief!!

[yeti racing]

Originally Posted by NJ 1161

Sounds good. I Work in Stevenage so drive your way every day but not in the Bm.

Where do you work?

Some genuine. Would of done all oem if I had done conversion and considering changing some bits, but may just be my OCD as all looks good!

Where abouts?

[xs2man]

I wouldn't worry about making power with a filter, its just unlikely to happen. Have a look at these 2 videos:

Ok. Its almost 20 mins of your time, but you will realise that its ALL for the noise, and maybe a small reduction in power.