2015 M5's to feature electronic wastegates

[brainblade]

My 2013 Bmw m5 has been a great car but has had a series of issues that require fixes. One has been the suspension clunk which has been updated with progressive springs. The second has been squealing brakes which initially were described as "normal" for M cars but later were fixed with updated pads and rotors to only warp now after 700 miles of driving. Ive also had low frequency cricket sound coming from dashboard which was first described as "high pressure fuel injectors" to now being pinpointed as a wastegate issue. Apparently on N54 engines, there was a common wastegate rattle. Im not sure what is causing the low frequency chirp-whine or cricket sound only when gas is pressed but it appears something in wastegates such as the solenoids, actuators, or something else. Its in the shop now so should know soon. So it appears that beginning with 7/2014, m5s will have electornic wastegates. What is the benefit of e-wastegates other than making after tuning difficult?

[Netwon]

In a normal turbo charged gasoline engine the crankcase is not under vacuum when when under boost. In our cars with valvetronic lift with double vanos (2012 F10 M5+) the engine is using valve lift instead of a conventional throttle plate to control engine speed thus with the throttle plate normal position 100% open therefore is no manifold vacuum to draw off of like a NA engine. To combat this there is a vacuum pump under the hood to make up for this.

As the electronic-over-pneumatic (I/P) waste-gates are always adjusting when the engine is under load you require ample of vacuum to control them. As the brake booster, exhaust flaps and other systems require vacuum to function a accumulator tank is located under the engine. The reserve vacuum is stored there for periods of peak demand. This helps to keep the vacuum pump small and manage extra engine load.

Fully electronic valves will result in less load for the vacuum system, less vacuum lines and hopefully a more reliable faster responding system boost pressure control.

When you control a system via I/P there is a delay in electronic signal from the DME to solenoid on the pneumatic actuator to final control element the waste gates.

All of this means you need a safe margin of error with all of this to keep the engine boost in the safe range. This margin of error is a loss of power.

So in a nut shell you get...

Better boost control, less mechanical parts and a simpler system that can keep finer control of engine boost!

Worse is that the DME is directly controlling the waste gates making it harder to play with boost pressures without cracking the DME.

Hope this helps!

[brainblade]

Wow thank you for the thorough answer. So the subtle noise i am getting when the throttle is depressed? it sounds like a high frequency cricket/grinding noise only when throttle is depressed albeit subtle. At first , i thought it was the speedo( like a gear spinning in cluster) but when we opened the hood it is pretty clear its from engine. I have heard the wastagte rattle from n54 engines and its not to that degree. Any specualtion appreciated.

[avlnch]

Originally Posted by brainblade

Wow thank you for the thorough answer. So the subtle noise i am getting when the throttle is depressed? it sounds like a high frequency cricket/grinding noise only when throttle is depressed albeit subtle. At first , i thought it was the speedo( like a gear spinning in cluster) but when we opened the hood it is pretty clear its from engine. I have heard the wastagte rattle from n54 engines and its not to that degree. Any specualtion appreciated.

Some people who upgrade their downpipes get a waste gate flutter noise when you let off the throttle.

How do you know 2015 models are getting electronic waste gates? Haven't been reading on BP lately, did I miss something or is it a rumor / possibility?

[Boss330]

AFAIK the M5 allready has electrically operated wastegates, beginning with the 07.2014 production.

For instance Dinan's piggyback isn't available for these later M5/M6 models due to the new wastegate design.

http://dinancars.com/product/d440-16...ries&mid=1163/

[PetrolFumes]

Originally Posted by brainblade

Wow thank you for the thorough answer. So the subtle noise i am getting when the throttle is depressed? it sounds like a high frequency cricket/grinding noise only when throttle is depressed albeit subtle. At first , i thought it was the speedo( like a gear spinning in cluster) but when we opened the hood it is pretty clear its from engine. I have heard the wastagte rattle from n54 engines and its not to that degree. Any specualtion appreciated.

I hear a similar noise but more of a buzzing coming from the engine and can only hear it when on the throttle when the windows are down....is this what you are hearing?

[mpower3330]

How much better is the electronic wastegate? Is it a game changer?

[variable229]

Originally Posted by mpower3330

How much better is the electronic wastegate? Is it a game changer?

Yup with less moving parts to increase reliability and a electronic wastegates hold the boost to offer more discrete control over a traditional mechanical one. Think better tunes and boost control.

I believe the 2014 F10 were last engines using mechanical wastegates and now every BMW turbo model going forward will use electronic now.

[brainblade]

Originally Posted by MPowerrF10

I hear a similar noise but more of a buzzing coming from the engine and can only hear it when on the throttle when the windows are down....is this what you are hearing?

I hear it in the cabin...you can check yourself although once you try and listen for it you may always hear so it its up to you to try---turn off all climate control and radio and with windows up keep throttle at idle then slowly increae throttle to 3 or 4ooo rpm and you should hear it if you actually have it. Releasing the throttle should stop it. so it only comes on when throttle is engaged. Mine is in the shop and they said its wastegates although i have not heard back since monday.

[saflang]

They told me it is due to the new injector type as it now is much larger and only has a plastic housing.
It's a very annoying sound.

[Fantasm]

Originally Posted by variable229

Yup with less moving parts to increase reliability and a electronic wastegates hold the boost to offer more discrete control over a traditional mechanical one. Think better tunes and boost control.

I believe the 2014 F10 were last engines using mechanical wastegates and now every BMW turbo model going forward will use electronic now.

Too bad we have no tunes available cause no one has cracked the ECU yet.

I think no one is really trying hard enough on the M5 ECU.

New M3/M4 is already at 530WHP with just piggyback and E85.

[PetrolFumes]

Originally Posted by brainblade

I hear it in the cabin...you can check yourself although once you try and listen for it you may always hear so it its up to you to try---turn off all climate control and radio and with windows up keep throttle at idle then slowly increae throttle to 3 or 4ooo rpm and you should hear it if you actually have it. Releasing the throttle should stop it. so it only comes on when throttle is engaged. Mine is in the shop and they said its wastegates although i have not heard back since monday.

Any news from the shop?