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This has been mentioned before in various threads but I felt it deserved it's own thread to make the information easier for members to find. Recently, BMW upgraded the design of the recirc/DV. Gone is the rubber diaphragm which has been prone to tearing causing all manner of boost related issues.
The new diverter valve P/N is 11658636606 and is available from several of our outstanding forum vendors for approximately $65.00.
As you can see its not hiding any diaphragm up its sleeve.
Note the holes in the piston assembly.
This allows pressure to build on the back side of the valve seal, allowing it to expand and seal better than would be the case with a simple o-ring.
I will try and verify if the Alta stiffy spring is compatible with this unit this evening.
Yes it will fit all MCS and JCW turbos to include the Owens, JMTC and other Mini Cooper KO4 hybrids.
Note: Just in case anyone is wondering it will not fit other BorgWarner turbos such as the EFR 6258. The piston is about an 1/8 of an inch too short and the bolt pattern is different.
Tigger, what would you recomend for diverter valves, the oem or the forge recirculated valve, for a stock car or let say someone who is running manic stage 2.
The Forge unit while a very nice design uses a pneumatically actuated piston. Over time the piston gets dirty and can bind. When this happens you have to remove the valve, disassemble and clean it. The factory valve never had this problem but didn't hold up well in heavy boost applications for long before the diaphragm would cry uncle.
This new unit eliminates that problem, doesn't need periodic cleaning, is inexpensive and retains ECU control of the valve unlike the Alta BOV that works solely on pneumatics and only works on the N14.
Sorry for the delay, Vlad needed a new timing chain and water pump. Now that that's out of the way lets get back to the subject at hand. It would appear as if the Alta stiffy spring will fit the new valve. I didn't feel like taking Vlad back apart and removing the Alta spring but luckily I had a couple of extra turbos floating around.
Here's the 273 and 606 valves.
Here's a close up of the springs. The 606 is on the right.
Here's the 273 spring.
And the newer 606 spring.
The diameters appear identical and I opened up another bov which had a spring length in between these two. So there appears to be a small amount of variation in the springs. After I upgrade Vlad's valve and drive it for a bit I'll install the Alta spring.
So yesterday between installing tunes I had an extra 15 minutes and swapped out Vlad's 273 valve w/Alta spring for the new 606 and thought I'd follow up.
1st When holding both units and pressing the piston plunger assembly the newer valve appears to need slightly more pressure to open but once open moves more freely.
2nd When releasing the plunger assembly the newer valve closes much more rapidly than the older valve even with the Alta spring. It would appear that the rubber diaphragm slows the movement due to the rolling of the rubber.
3rd The Alta spring is slightly smaller in diameter and doesn't fit as well in the machined recess on the piston assembly of the newer valve. It should not interfere with it's operation however.
Driving impressions:
1st The new valve with stock spring holds 22+ lbs of boost with zero issues.
2nd The sound produced when the recirc valve opens is different from the older valve. Not in a bad way just slightly different. Kinda hard to describe.
3rd The older valve would sometimes make a staccato sound when snapping the throttle closed in high boost situations. The newer valve simply opens and closes, no muss no fuss, as you get on down the road.
Overall I'd give the new valve two thumbs way up and would highly recommend it to anyone looking for a replacement for the older factory valve. Pelican, ECS and Way all have great prices of at least $30 less than the dealer on the new and improved valve so please support our forum vendors and save some money at the same time.
So yesterday between installing tunes I had an extra 15 minutes and swapped out Vlad's 273 valve w/Alta spring for the new 606 and thought I'd follow up.
1st When holding both units and pressing the piston plunger assembly the newer valve appears to need slightly more pressure to open but once open moves more freely.
2nd When releasing the plunger assembly the newer valve closes much more rapidly than the older valve even with the Alta spring. It would appear that the rubber diaphragm slows the movement due to the rolling of the rubber.
3rd The Alta spring is slightly smaller in diameter and doesn't fit as well in the machined recess on the piston assembly of the newer valve. It should not interfere with it's operation however.
Driving impressions:
1st The new valve with stock spring holds 22+ lbs of boost with zero issues.
2nd The sound produced when the recirc valve opens is different from the older valve. Not in a bad way just slightly different. Kinda hard to describe.
3rd The older valve would sometimes make a staccato sound when snapping the throttle closed in high boost situations. The newer valve simply opens and closes, no muss no fuss, as you get on down the road.
Overall I'd give the new valve two thumbs way up and would highly recommend it to anyone looking for a replacement for the older factory valve. Pelican, ECS and Way all have great prices of at least $30 less than the dealer on the new and improved valve so please support our forum vendors and save some money at the same time.
Great feedback and analysis. Might have to pick one up sooner than later...
Glad to pass the information along. Thanks should really go to one of my customers that originally brought the new part to my attention in early April (Thanks GS) and to BMW for finally addressing the problem.
Sending some more thanks for posting this info as well. I've recently had the 28AA code (divert air solenoid plausibility / ECU seeing to much boost) show up and throw the car into limp mode twice. Both times at track events while running Manic stage 2, map A & B. I haven't been able to get the car to throw the code while off track. As you can imagine, it's been a frustrating situation. Thankfully, in both instances I was able to switch my tune back to stock and the cel didn't reappear. So fortunately, the weekends weren't wasted. The fun dial was just down a little ;-P
I had the Alta spring in... I've since read that the spring isn't any good for automatics. Anyhow, when I came home from this last event, I pulled the DV and replaced the stock spring back in. The diaphragm looked in fine shape and clean. I've since attempted some spirited street driving, lol, keeping the RPM's high and getting the temps up. The code hasn't reappeared. I'm going to leave it alone at this point. If the code reappears, I'm guessing I'll try loosening the waste gate adjustment next. After that, I'll try swapping out to this new stock DV valve. next, i figure I'll look at the pressure converter... 1 potential fix at a time.. Regardless though, this new DV seems like it will be going in sooner than later, judging by what all I've read about the old ones failing.
Anyhow, thanks again Tigger. Side note: has anyone else had any experience remedying the 28AA code?
We just blocked mine off during some fault analysis (we were seeking reasons for loss of boost) and it hasn't been in use since. I'd personally not be spending any money on one and just block it off. So far, so good running "lots of boost and lots of power" in mini terms anyway, with no issue.
So, it's been five months since the first post. How are these new valves holding up for folks? Any issues?
Vlad routinely hits 22 to 23 psi with no issues so far. None of my customers have had issues with theirs either. More time will tell for sure but so far it's looking good.
Vlad routinely hits 22 to 23 psi with no issues so far. None of my customers have had issues with theirs either. More time will tell for sure but so far it's looking good.
Awesome! I had already bought my Forge recirc valve before you posted this thread (a year ago or more) but it sounds like this revised OEM part would have been a great choice instead.
Glad to pass the information along. Thanks should really go to one of my customers that originally brought the new part to my attention in early April (Thanks GS) and to BMW for finally addressing the problem.
Hi and thank you for a great feed back.did you have a chance to drive the car with the new DV but with Alta spring or just the test with it in there and pressing it.
Thank you.
Ben
Hi Ben. No I drove it for a while with the Alta spring and didn't see any issues even at 25 psi. It just works like its supposed to. I'm currently running a Turbosmart Kompact 50/50 valve and am very pleased with it as well. I didn't need the TS yet but I wanted to gain a better familiarity with it before boost levels climb north of 30. I just have difficulty trusting a piece of plastic under that much pressure.