M60B40 Folks - what intake/filter?

[TheGreenOx]

My car came with $20 autozone (not to knock autozone) ricer special air filter. Was maybe 2" thick. Replaced it with a $30 ricer special that was about "4 thick (or high, depending on how you look at it) and did notice a difference. But it still sucks. No airbox, no heat shield, just zipties dangling right above the

Given that a replacement stock airbox is either going to be hard to source (junkyard/here) or crazy expensive (OEM replacement) it just makes sense to put a performance bit in there. I have read (perhaps unreliably) that the stock airbox flows just fine with a K&N or similar in it. So if that's the better option I'll take it.

I have seen a shot of a 540 engine bay that had a beautiful dual-cone side-by-side elements in a heat shield. Elements were blue.

Low end would be my higher priority (that's why i bought a V8!) and the more I think about it the more I like the idea of DIYing something into the fender well.

Thoughts, options opinions?

[me78569]

I would just see if someone is parting a 540 and get the airbox. I am sure someone would be willing to part with it for cheap, I would have sent you the one I had in the corner of the garage for the price of shipping if I still had it.

I am curious about the 3.46 lsd you have though........ how do you like it? where did you source it? when does the 3-4 shift fall when you're on the loud pedal?

[bubba966]

You want good performance? Put the factory air box back in it. Get one off of someone here in the classifieds section. I'm sure someone has one sitting around. Make sure it's a B40 box and not a B30 box as the B30 box is smaller. The factory box is very, very well designed and all other aftermarket or diy designs make it sound meaner but don't add any (sometimes even take away like it sounds your current setup is doing) performance at all.

[T444E]

My car came with $20 autozone (not to knock autozone) ricer special air filter. Was maybe 2" thick. Replaced it with a $30 ricer special that was about "4 thick (or high, depending on how you look at it) and did notice a difference. But it still sucks. No airbox, no heat shield, just zipties dangling right above the




Killer pun bro.

[Sneezy]

It won't be that hard to source. There are several guys here who break these things regularly enough.

Just get the OEM bits.

[TheGreenOx]

I like it, thanks. Would it be worth constructing some kind of runner to suck outside air or is there already one in place factory?

3.46 came with when I bought it. I'm told its a big case and that it came from a 7. Haven't looked into that as much as I shoulda yet. Car spins up amazingly, its almost like the car is accelerating too fast for the engine to really work hard. Having never driven a stock diff, I can't speak to differences. The biggest crapper of it is that at 70MPH i'm around 3K RPM. Cruising in the power band is not great for mileage, and it takes attention to maintain a legal speed - especially since the thing is just as smooth at 110 as it as at 65. Also makes for great fun to be able to break traction in almost any gear. It does make for a lot of work shifting to keep it in a optimal RPM range, but the flipside is you can put it in third and just not shift from 20-65mph. Gears are high enough that I can drop in 6th and do 45-50mph and get around 25mpg around 2k rpm - which I figure is where the stock diff would put it at highway speeds. I'm thinking having the higher rear end might be handy when I get it sorted well enough for autocross. But having a non-stock LSD might put me in some crazy ass unlimited class.

3-4 shift at full tilt near redline would put me around 80+... so it doesn't happen much. When I go to work at 7am most mornings, the highlight of my whole day is often going 25-80 without shifting. I do wanna know exactly though, will report.


Killer pun bro.


so glad someone saw that.

[T444E]

A 3.46? That would mean it's a medium case diff, you car takes a large case. Unless you mean 3.64 which were open diffs in later 750iL.

[TheGreenOx]

it is very likely I am mistaken about the case itself. Is a medium case a bummer?

[T444E]

No it's just what other E34s had.

[MazDuh]

a stock B40 box is your best bet. I cut the snorkel off of the front of it and built a small shield to keep engine bay air out of there. Sounds good, works well and i used an AFE panel filter. Can't say if it made it any faster, but it seemed like it.

-Eric

[K Fox]

Again, another vote for the stock box. I bought my 94 540 with one of those cones on it, and thankfully I got the stock box with it. Yes, it sounded 'louder' with the cone, but it was noticeably quicker with the stock box back in and a normal paper filter. BMW spent a lot of time/money designing this car, and several areas are very hard to improve on - one of them is the intake. I encourage you to search it and read the many threads, all of which seem to come to the same point I just made.

Also, paper filters work fine - there's plenty of surface area on the filter to supply all the air the engine needs - but it's a well known fact that the paper filters are much better filters, and keep more crap out of the engine, which I say is very good for longevity. My $.02

Fox

P.S. Another way to think about the intake is just like the exhaust on these: you cam make it louder and you can make it lighter, but you can't make it 'better'. This is where the engineering then was better than the aftermarket stuff is now.

[jehu]

If its of any interest I have been using an aFe Pro Dry S filter in the stock box and have had several Used Oil analyses done which show no evidence the filter is failing to filter properly. Liking the idea of a longer life , less restrictive than paper but not oiled I gave it a shot. Haven't found a strong reason to revert to the OE paper

[Shoomakan]

http://img684.imageshack.us/img684/1981/20120828181751.jpg


Because raceTouring. :P

I've personally tried several combinations here. Sticking a K&N filter in place of the stock box INSIDE the engine bay made it feel a bit stronger down low, and weaker everywhere else. Sticking it out of the high beam has been good so far. It sounds great, looks very aggressive, but requires more maintenance on your part. I'm aware of the extra particulates that seep in, and that a filter that exposed requires more regular cleaning. I change my oil every 2500 miles, and clean the filter once every 2 weeks.

The butt dyno might lie, but I did a few runs before and after and there was a measurable improvement. So I'm happy with it. Required a little modification, though. I want to cover it with a cloth mesh to help keep it clean and do away with the red parts.

And for those wondering.. It's faster. Much faster. :devillook

[Cheche]

I say try to get the OEM box, as many pointed out above, BMW spend a lot of money developing these cars and that shows, I am stuck with a K&N filter since I swapped the B30 for a B40 and I am not able to find the top part of the OEM box.

PS: if anyone here has one handy or know someone who does, send me a PM, I have paypal ready and just need it shipped to Miami