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HI just wondering if anybody can help me does a e34 m5 3.6 need the air pump on the engine or can it be done away with. and if it does need it what is it purpose have already done away with the air con anyway thank would be great if anyone:) could help.
 

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Air pump is not required in UK.

It pumps air into the exhaust stream at cold start to dilute the burnt charge prior to entering catalyst.

It was a requirment for US market only.

It adds weight.

It adds rotational inertia.

It adds FEAD load.

It spoils the exhasut gas flow in the exhaust manifold due to two pipes sticking into the gas flow.

It carries the alternator / AC belt tensioner assembly which is a pain.

Place in bin and smile!
 

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Search air pump as there are several discussions about removal and air pump function. The pump is primarily there to have faster cat warmup for emissions. If you are required to have emissions testing it is a required funtional part.
 

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We have done away with air pump and a/c on Sebring Sienna .......... noticable improvement in performance .

Gets bloody warm in mid July though !

D
 

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Why do you need it if you have emissions testing? Cant you just make sure the car is properly warmed up before taking it through the sniff test?
 

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Depends on location. In California you would fail the visual inspection if it was missing
 

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Here's a youtube video showing what one owner did to make up for removal of the air pump on his M5:
E34 M5 air pump delete - YouTube
I had mine replaced after my stroker build and tried to use the 33" belt that was suggested in the video but this was too long for my setup. I ended up using a 31" belt. Because the actual belt tension adjustment for the shared A/C and air pump was on the air pump mount, I had to loosen the bolt on the AC compressor mount and "wiggle" it to make the belt fit. It was a little tight but I figured there will be some "stretch" to the new belt after some use.
If you can, I'd suggest buying a few belts in various lengths to test fit the best belt size. My local auto parts dealer got to know me really well after I kept buying and returning various belt sizes...:biggrin:

Hope this helps.
 

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That was me in that video :byee55amg

I ran the car with the belt only with no problems for about 2 months until I came across an M30 bracket and tensioner which I modified to fit.

The removal of the bracket air pump/condesner wasn't too difficult, but there are 2 bolts tucked behind the harmonic balancer that were a pain to get out. Be sure to have a tiny ratchet or be prepared to remove the harmonic balancer.


First off, here is the M30 A/c bracket and tensioner.




Now, here is the M30 bracket next to the S38 bracket. (M30 on right)






First thing you would notice, is the S38 bracket looks huge next to the M30 bracket. Next thing is overall weight...The M30 bracket is aluminum. The S38 bracket is much heavier to apparently support the air pump. The difference in weight is substantial...


M30 bracket (In pounds):





S38 bracket:





Most importantly, the M30 bracket is a direct bolt on to the S38 block. However, the ac compressor [COLOR=blue !important][COLOR=blue !important][/color][/color]mounts on the M30 bracket are higher up and inset more than the S38 bracket. It is possible you could mount the AC compressor using the M30 bracket alone, but the ac lines would have to be re-bent. Not worth it IMO.


I began work on making a new upper mount for the AC compressor. About an hour later, I had the mounts ready, and bolted on the compressor.






The compressor sits a little lower than it originally did. The tensioning bracket is at an ideal angle either, but it does it's job.



Fortunately, the plastic under-shield still fits.

After a full day of work, my s38 is completely air pump-less, and I managed to clean up the engine bay, potentially gain some power from less parasitic drag, and shed some weight.

How much does the entire air pump system weigh? (Missing a couple hoses etc.)




Not that much. However, for a days work it was worth it!

If you plan to take on this project, be prepared for a full days work. Upper compressor mounts will need to be fabricated, but it is nothing someone with basic mechanical skills cannot fab up rather quickly. I've been the setup above since August or so with great effects!


:cheers:
 

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I am planning this project as well, and have the M30 bracket, blockoff plates for the air injection nozzles, little gaskets , new copper plated nuts and M30 AC lines (hope they work as they are bent to fit an M30) so I don't need to fabricate a spacer for the top mount of the AC compressor.
 

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I tried to use search, but I didnt find answer.

What should i do, if i delete the air pump and also the manual ac? What belt should i use, or do i need any belt if both deleted? Any other things to keep ind mind? I'm trying to lose weight from my -89 M5, because i'm preparing car for track. And the ac doesn't work anyway, so its same to take it of too. Im just a rookie with cars (as you can see) and I would appreciate any advice :)


Antero
 
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