Fitting a E60 M5 MAF to a C230K, any comments or experiences?

[John Jones Jr.]

Guys,

As per the thread title.

Anybody done it or know of anybody who has?

Any idea what I should expect or is it even worth doing in the first place?


I've now relocated my MAF up closer to the throttle body, haven't noticed any differences except the slight 'flat spot' that was there before between 3000-4000 RPM is now more pronounced. I'm wondering will a M5 MAF cure this or is my current MAF on it's way out?

[KrumB]

Hi J,

I'm using exactly the same MAF (Bosch 0280218062) and the car runs perfectly even without moving it closer to the throttle body. I changed it myself and after a few days went to a MB dealer to adopt it and they said it's not needed.
It's a perfect solution.
Cheers
Krum

[dokotela]

dont know if its gonna sort out your troubles...check what error codes are thrown....if its O2 upstream..then its most probably MAF.

just did this mod literally 2 hours ago.
anyway, heres what i found on an untuned C230K with a kleemann crank pulley and 63mm(2.5")exhaust.
with my stock MAF overfuelling like crazy on idle and on part throttle, i dyno'd the car and the air fuel ratio was between 14.5 and 12.9 at WOT. on switching to the E60 M5 MAF, at WOT the air fuel ratios were lower, more like between 14.0 and 11.5.....but no more overfuelling at idle and part throttle. so i figured i could live with this until my SC mod is complete...and got the bosch 4bar regulator on back order from germany....very cheap...approx $60-$70.
as well, the MAF is about $90-$100 for the M5 and more like $250 for the C230K directly from bosch.
also i believe that the MAF will go through some adaptation over the next 2 days or so, so i'm excited about the power prospect cos prior to the change i got 170-180kw at the fly and 330-350nm working on a 20-25% drive train loss.
post MAF change, i instantly hit lower which i sneered at initially and then asked my mech to run it again. to my surprise the power was up and even higher on the 3rd run.
i'm currently at the same power but the torque had now jumped to 350-375nm depending on the drive train loss. that's exciting

[John Jones Jr.]

All good & positive news, cheers guys.

Two questions.

1. Can I buy just the M5 MAF on it's own without the MAF housing?

2. Do I need to change to a 4bar pressure reg, as I'm only fitting an over size crank pulley?

[dokotela]

yes the hot wire is available without housing...thats how the original bosch is sold these days
and no u dont need to change to 4 bar regulator with crank pulley only

[dokotela]

yes the hot wire is available without housing...thats how the original bosch is sold these days
and no u dont need to change to 4 bar regulator with crank pulley only

[John Jones Jr.]

Thanks Doc.

I think I'll take the plunge and order one now.

[KrumB]

Try this one:
http://stores.ebay.co.uk/Ralf-Luecke...=p4634.c0.m322

[KrumB]

Try this one:
http://stores.ebay.co.uk/Ralf-Luecke...=p4634.c0.m322

[John Jones Jr.]

Thanks K-B. I did order one, pity I didn't see your post first as the one I ordered, a Bosch one also, was a €31 more expensive. Life!

[John Jones Jr.]

Thanks K-B. I did order one, pity I didn't see your post first as the one I ordered, a Bosch one also, was a €31 more expensive. Life!

[John Jones Jr.]

Here's a possible point of interest.

I decided this morning to refit the MAF fliter/gauze that I had removed while relocating the MAF, as in the back of my mind it might have some bearing on the air flow in relation to the MAF itself. I just gave the car a quick blast and the 3000-4000rpm 'flat spot' wasn't present, nor any other flat sport for that matter? I suppose it's very possible the MAF is designed inconjunction with the filter/gauze present and it has an effect on the air flow passing the MAF?

I will do another longer drive soon just to double check.

[dokotela]

It's probably the dirt that was affecting it. Use some MAF cleaner and u should be good

[John Jones Jr.]

From what I can tell Dok, I checked it twice and on both occasions it was spotless, no even the slightest smear of oil either.

[John Jones Jr.]

Went out for another drive just now and got the engine up to fully working temp, did about 20 miles, no 'flat spot' ! Happy days. Wonder will I notice any difference with new M5 MAF? Doubt it but, there might be a better AFR across the rev range? What do you think Dok?

[KrumB]

It'll be great if you can measure the AFR before and after. I'm very curious.

[John Jones Jr.]

K-B, I'm curious too. I'll see what I can arrange. Wonder would the local Merc specialist (don't really know the guy) be able too, then again he's no rolling road.

Another thing on reflection of this evenings drive, after refitting the filter/gauze along with the MAF relocation I'd almost swear that there's an improvement in throttle response. Now that could just me wishing for an improvement but for sure there's no 'flat spot' now.

[Mike51809]

The gauze and screen is there to stabilize the air so the sensor can get an accurate reading and that could defenitly be why you had a flatspot

[John Jones Jr.]

Howdo Mike.

Yes, I was thinking that alright that's why I replaced it and so far it has done the job. I'll be taking the car for a long run on Saturday, I should know for sure if it's solved the problem, at present all is good.

[dokotela]

Went out for another drive just now and got the engine up to fully working temp, did about 20 miles, no 'flat spot' ! Happy days. Wonder will I notice any difference with new M5 MAF? Doubt it but, there might be a better AFR across the rev range? What do you think Dok?

if your fuel quality is up to standard, then i doubt that there will be an increase in power. you will have lower air fuel ratios for sure which is actually more of a guarantee than anything at this stage, u need to test cruising a/f ratios to see whether the car will actually be heavier on fuel or not. i'm currently doing the longer experiment, just filled the tank and checking what mileage i get out of it.

glad your problems are sorted though. i personally think you should maybe test a/f ratios before and after crank pulley install cos chances are u might not need the new MAF. but if u did the sc mod as well, then it would probably be a different story

[John Jones Jr.]

You're right about testing AFR before & after but I don't have an AFR gauge, so it's all seat of the pants testing (which generally means I ain't really got a clue of what's happening!). Will do a couple of MPG checks (tank to tank) now that you've mentioned it.

[John Jones Jr.]

Dok, a few question for you if you don't mind.

I fitting my new over sized next week, should I fit the M5 MAF too?
What I'm concerned about is the engine running too lean ( I've no way of checking the AFR) and I've have read some horror stories on one or two SLK sites (of course among positive stories also) about just fitting the over size pulley.

Are you fairly sure I don't need to up the fuel pressure and run cooler plugs?

Also, how necessary is it to have the engine remapped?

Thanks in advance.

[KrumB]

I did exactly that.
Don't worry. The increase in pressure should be about 0.3 Bar and the ECU is retarding to compensate to the lean mixture so harm happens to the engine. ( the anty knock sensors come into play)
Cheers

[John Jones Jr.]

Great to hear K-B. Would you expect the M5 MAF worthwhile with the over sized pulley?

[KrumB]

J
Never compared but no complains from the BMW MAF from me so far. In fact I think it works better with the ECU than the OEM one in cases like ours.