M5 airbox to plenum/tube fit issues

Specific conversations and info for the BMW E28 M5 and M535i.
pas
Posts: 30
Joined: Aug 30, 2010 11:55 PM
Location: MD

M5 airbox to plenum/tube fit issues

Post by pas »

Working on changing out my air filter and removed the air box on my M5, but before I did, I noticed the very poor fit between the plenum/tube from behind the left headlight to the hole in the airbox. See pics at

http://www.flickr.com/photos/89905286@N ... 172739453/

I can't see any easy way to adjust anything that would make the tube seat properly in the inlet. I also understand that the foam gasket (falling apart on mine) is the same as that on the E30 and that part is still available.

Any hints or comments to fix this in an elegant way or reasonable manner?

Also, has anyone ever made a plastic replacement for the roughly 8lb or so large metal air box?

TIA[/url]
Mab1957
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Joined: May 14, 2010 1:33 PM
Location: Northern Virginia, USA

Post by Mab1957 »

The donut or washer-gasket is available from Blunttech.com. PN 13711312695 It will cover that gap.

There are a few discussions about the M5 airbox on this forum. Give it a search. Your research will reveal that others have determined the guys in white coats in Bavaria built a box that maximized the airflow. After market systems don't help a whit. The airbox and those pieces are very hard to find. If you do decide to go another way do not discard them. Pull it off, prepare the surfaces and apply a coat of paint to it. You might even find a reproduction of the sticker with a bit of research.

Where are you located? I'm in No. VA.
pas
Posts: 30
Joined: Aug 30, 2010 11:55 PM
Location: MD

Post by pas »

Thanks.

I'll leave it stock; it is just the fact that it has so much mass for an airbox and it is hanging out up front. Different era and I actually appreciate the sheer solidity of the approach.

I'm in the Frederick, MD area.

thanks

pas
Mab1957
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Joined: May 14, 2010 1:33 PM
Location: Northern Virginia, USA

Post by Mab1957 »

Good deal. There are some nice roads up there. Perhaps I'll see you on a drive someday.

Matt
pas
Posts: 30
Joined: Aug 30, 2010 11:55 PM
Location: MD

Post by pas »

Yep. Roads north up towards Gettysburg and Mount St. Mary's are great.

Are you sure about the PN (PN 13711312695) - it isn't showing up at blunttech or realoem.

About 10 years ago I was looking at an M5 and had it tech inspected by the guys at Intersport in McClean, VA. They had a BMW master tech even though Intersport is a Porsche specialty shop - really good work (I'm a card carrying PCA member for various reasons including the E500 I used to own). Didn't buy that one since it had two cylinders down from the others on the leakdown test.

pas
M5BB
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Location: Peachtree Corners, Georgia

Post by M5BB »

IIRC there is a "foot" on the bottom of the airbox that has to fit in the proper place or the box will not go down far enough.
Also check the plastic cover that the intake of the airbox matches up to so it is in the proper position? I should have a locating pin that twist locks into place.
HTH
Gary
Mab1957
Posts: 2244
Joined: May 14, 2010 1:33 PM
Location: Northern Virginia, USA

Post by Mab1957 »

pas wrote:Yep. Roads north up towards Gettysburg and Mount St. Mary's are great.

Are you sure about the PN (PN 13711312695) - it isn't showing up at blunttech or realoem.

About 10 years ago I was looking at an M5 and had it tech inspected by the guys at Intersport in McClean, VA. They had a BMW master tech even though Intersport is a Porsche specialty shop - really good work (I'm a card carrying PCA member for various reasons including the E500 I used to own). Didn't buy that one since it had two cylinders down from the others on the leakdown test.

pas
Hmmm, I have two in a bag fresh from Steve at Blunttech. I pulled that # off the bag. I'll check my order to Blunttech and see if there was a different RealOEM number used. I'm not at home now so can't confirm.

Good points by Gary ^^ here. There is a positioning "foot" that could hold the box up/inboard if not in its shoe.
pas
Posts: 30
Joined: Aug 30, 2010 11:55 PM
Location: MD

Post by pas »

Thanks, Gary. It appeared properly seated on the rubber buffer though I'll check it more carefully when I reinstall it.

The plastic thumbscrew for the intake piece connection to the headlight frame is positioned correctly.
Karl Grau
Posts: 9708
Joined: Mar 10, 2006 7:34 PM
Location: Sandy Eggo

Post by Karl Grau »

I got tired of the sorry state of my foam doughnut. It never sealed correctly and was always getting mangled. I tried to use double sided tape to make a better seal but I still always ended up with warm air coming in around all the gaps.

I bought some foam pipe insulation that is the same stuff as the factory foam (had to buy six feet though). So I cut a test piece which turned out to be a little wide but I tweaked it a little and now I FINALLY have a good seal.

The OEM ring.

Image

Bulk

Image

Test piece, looks just like the stock material.

Image
ahab
Posts: 6174
Joined: Jun 11, 2006 9:12 AM
Location: Chalfont, PA

Post by ahab »

Karl Grau wrote:Image
Dude, are those JVC GB-1E speakers in that photo?
Karl Grau
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Post by Karl Grau »

ahab wrote: Dude, are those JVC GB-1E speakers in that photo?
You have an eye for detail ;) .
1st 5er
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Post by 1st 5er »

Karl Grau wrote:
ahab wrote: Dude, are those JVC GB-1E speakers in that photo?
You have an eye for detail ;) .
All I see are couple of drunk flamingos. :oops:
Karl Grau
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Location: Sandy Eggo

Post by Karl Grau »

1st 5er wrote:All I see are couple of drunk flamingos.
Well, obviously you don't have an eye for detail. :)
(and the flamingos are just napping)

Image
1st 5er
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Post by 1st 5er »

I know what the next purchase with my Home Depot gift card will be.
That is unless you're willing to turn your purchase into a group buy. :D
To make it easy, what's the ID of that piece?
igotbank
Posts: 911
Joined: Aug 06, 2007 10:15 PM
Location: NY

Post by igotbank »

Karl,

I would've never thought to have used that. Which diameter did you get. I'm at work and will be making a Home Depot run after lunch today. I love this forum! Thanks and Happy motoring.
Karl Grau
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Post by Karl Grau »

The ID is 3-1/8 and it was $12.46 for 6' at McMaster-Carr. I don't think Home Depot carries anything that large but I could be wrong. Mcmaster-Carr ships it it a long box with a cardboard tube in the center. shipping was $17.00 but that was with a bunch of other stuff.

I'd be happy to send a piece to anyone that wants one for shipping cost. I figure a 6"- 8" piece would be enough for a lifetime of doughnuts.

If anyone wants to buy from McMaster, it's item #4463K145
Ultra-Flexible Foam Rubber Pipe Insulation
.
Last edited by Karl Grau on Jun 05, 2013 8:08 PM, edited 1 time in total.
1st 5er
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Post by 1st 5er »

PM incoming.
ahab
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Post by ahab »

PMing
1st 5er
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Post by 1st 5er »

PP sent. :beer:
Karl Grau
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Post by Karl Grau »

Sherman & Aaron,
Your packages will go out tomorrow. Thanks for the overpayments, beer will bought and drunk (drank?:?) in your honor.
ahab
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Post by ahab »

Thanks for blazing the trail!
1st 5er
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Post by 1st 5er »

Karl Grau wrote:Sherman & Aaron,
Your packages will go out tomorrow. Thanks for the overpayments, beer will bought and drunk (drank?:?) in your honor.
Headed to the store... :D
igotbank
Posts: 911
Joined: Aug 06, 2007 10:15 PM
Location: NY

Post by igotbank »

You're right again Home Depot didn't have it. Pm coming
1st 5er
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Post by 1st 5er »

Got my box today. Pleasantly surprised; Christmas in June.

Chas, you shouldn't have... :shock: :oops: :D
Last edited by 1st 5er on Jun 09, 2013 8:40 PM, edited 1 time in total.
Karl Grau
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Post by Karl Grau »

I haven't heard anything more from igotbank so it looks like I may have one piece left (i'll give him until tomorrow in case he's having a wild weekend). All other pieces have shipped or will go out tomorrow. I hope it's all you dreamed it would be and more. :)
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