[Zer0Cool92]

What kind of gains would one see in performance and sound if I installed the stock f10 m5 downpipes on my 550?

Are they any less restrictive than the stock 550 downpipes ?

[NJ550xi]

Looking for some info on this as well. Going to be installing the M5 exhaust, not sure if it's worth looking into adding M5 downpipes also.

Brian

Originally Posted by Zer0Cool92

What kind of gains would one see in performance and sound if I installed the stock f10 m5 downpipes on my 550?

Are they any less restrictive than the stock 550 downpipes ?

[Bmw doubles]

I don't think you'll see any gains. Grant it I have the n55, but I only saw an increase in the top end on mine with a VRSF because I already have a tune. I'm almost positive you would have to dial in a tune to take advantage of any DP.

Additionally, it didn't free up the spooling as much as I had hoped. What really free the spooling and gave better throttle response was the combination of DP and my new hi flow exhaust.

[747flyboy]

Check my post; http://f10.5post.com/forums/showthread.php?t=1169845

Bone Stock OEM 2011 550i Dyno 379 WHP. OEM M5 Down Pipes with NO TUNE 409 WHP a gain of 30WHP combined with a growling deep exhaust note. When combined with OEM M5 Down Pipes and OEM M5 Exhaust NO TUNE 424 WHP an additional gain of 15 WHP however lost the beautiful growling deep tone to an obnoxious loud raspy exhaust ( I hadd to add 4 additional resonators to regain the previous tone). The above hardware combination along with Burger Tuning JB Stage2 piggy back and pure 100 Octane+Torco 497 WHP an additional gain of 73 WHP.
I believe this setup is easily above 500 WHP if I were to eliminate the additional resonators but not a valid trade since I love the way this V8 engine deeply and graciously growls.

Good Luck

[Zer0Cool92]

Would you happen to have any sound clips ? Do you hear the turbos more ?

[747flyboy]

A very subtle turbo whine only audible during gear shifts. No sound clips since I am no more than 50Db. Maximum. It is a natural V8 quite tone at low to Mid RPM that gradually increases to sporty tone at higher RPM.

[Zer0Cool92]

Originally Posted by 747flyboy

A very subtle turbo whine that is only audible during gear shifts. No sound clips since I am no more than 50Db. Maximum. It is just a natural V8 quite tone at low to Mid RPM that gradually increases to a sporty tone at higher RPM.

So you're telling me these catted m5 downpipes make more or as much as catless downpipes ? Do they need any special modding to fit ?

[747flyboy]

I refrain from using custom shops to do anything on a car. They are full of Boloni when it comes to promises. BMW spends hours on engineering wind tunnels science and airflows to best manufacture effective components versus some welding shop with local ideas. Just think of the next better component an OEM has to offer if you were to ever upgrade. Short answer, YES and not to mention CEL and other complications. A perfect fit since Turbos exhaust outlets of both 550i and the M5 have the same 22mm outlet diameter. You may have to shave off a bit one of the mounting M5 DP's since it slightly protrudes on the area of the starter motor.

[550Reasons]

would the M5 DPs fit the 2011 550i's turbos without much modifications ?

[Zer0Cool92]

Originally Posted by 747flyboy

I refrain from using custom shops to do anything on a car. They are full of Bolony when it comes to promises. BMW spends hours of engineering wind tunnels science and airflows to best manufacture effective components versus some welding shop with local ideas. Just think of the next better component an OEM has to offer if you were to ever upgrade. Short answer, YES and not to mention CEL and other complications. A perfect fit since Turbos exhaust outlets of both 550i and the M5 have the same 22mm outlet diameter. You may have to shave off a bit one of the mounting M5 DP's since it slightly protrudes on the area of the starter motor.

Honestly I'm content with the power the 550 makes now. I'm looking for a increase in sound mainly.

Do the m5 DP hiss like catless downpipes, how would you compare the two ?

What other changes in the exhaust did you do ?

[FenixMike]

Originally Posted by 747flyboy

I refrain from using custom shops to do anything on a car. They are full of Bolony when it comes to promises. BMW spends hours of engineering wind tunnels science and airflows to best manufacture effective components versus some welding shop with local ideas. Just think of the next better component an OEM has to offer if you were to ever upgrade. Short answer, YES and not to mention CEL and other complications. A perfect fit since Turbos exhaust outlets of both 550i and the M5 have the same 22mm outlet diameter. You may have to shave off a bit one of the mounting M5 DP's since it slightly protrudes on the area of the starter motor.

This would be ideal logic IF BMWs engineering goals were the same as a performance shops... however performance and horsepower is at the BOTTOM of the list with automotive manufacturers especially with new CAFE standards and the even harsher Euro standards for emissions and economy.

So in short, if you want clean emissions, then yes, chances are there isnt much improvement available over stock, however if youre after power, then there is a TON of room for improvement on EVERY part of that car, ESPECIALLY in the computer.

[747flyboy]

Attached a diagram of both 550i (left side of diagram) and M5 exhaust manifolds and a diagram of the Down Pipes. Down Pipes are a perfect fit as you may see the identical diameter of both Down Pipe Inlets (however the body of 550i Down Pipes are more restricted due to 600 CPI or Cell of Ceramics per Inch versus the M5 200 CPI, M5 Down Pipes Tubing/Ducts are wider and more of a free flow) since Garrett/BMW opted to use identical Turbine and Turbine Housing section for both 550i and M5 Turbos but totally different Compressors and Compressors Housing section. Meaning M5 Turbos and 550i Turbos are not cross compatible unless the Exhaust Manifold is also changed. M5 Exhaust Manifold is cross banked (Cylinder 1,4,6,7 feed rightTurbo and Cylinder 2,3,5,8 feed leftTurbo) a genius BMW concept maximizing on firing sequence and the four cycle of a combustion engine at mid to high RPM the Turbos are in a continuous spool. The M5 Turbo Compressors rotate counter clockwise in opposing direction to meet the cross banked Exhaust Cycle. 550i left exhaust manifold feed left Turbo and right to right. Turbos rotate in the same direction. Sound is more apparent and aggressive, however no hissing. I hope this helps.

On a separate Note; Alpina B7 Turbos share same Turbo housing as 550i but have different internals such as Compressor Exducer and turbine wheel. They are rated at 507 HP vs. 402HP on Garrett Honeywell website and are a perfect match for 550i. About to install on my 550i. I will keep you all posted.

[Zer0Cool92]

Originally Posted by 747flyboy

Attached a diagram of both 550i (left side of diagram) and M5 exhaust manifolds and a diagram of the Down Pipes. Down Pipes are a perfect fit as you may see the identical diameter of both Down Pipe Inlets (however the body of 550i Down Pipes are more restricted due to 600 CPI or Cell of Ceramics per Inch versus the M5 200 CPI, M5 Down Pipes Tubing/Ducts are wider and more of a free flow) since Garrett/BMW opted to use identical Turbine and Turbine Housing section for both 550i and M5 Turbos but totally different Compressors and Compressors Housing section. Meaning M5 Turbos and 550i Turbos are not cross compatible unless the Exhaust Manifold is also changed. M5 Exhaust Manifold is cross banked (Cylinder 1,4,6,7 feed rightTurbo and Cylinder 2,3,5,8 feed leftTurbo) a genius BMW concept maximizing on firing sequence and the four cycle of a combustion engine at mid to high RPM the Turbos are in a continuous spool. The M5 Turbo Compressors rotate counter clockwise in opposing direction to meet the cross banked Exhaust Cycle. 550i left exhaust manifold feed left Turbo and right to right. Turbos rotate in the same direction. Sound is more apparent and aggressive, however no hissing. I hope this helps.

On a separate Note; Alpina B7 Turbos share same Turbo housing as 550i but have different internals such as Compressor Exducer and turbine wheel. They are rated at 507 HP vs. 402HP on Garrett Honeywell website and are a perfect match for 550i. About to install on my 550i. I will keep you all posted.

Yes definitely keep us posted about the alpina turbos..

Also, if the stock f10 m5 downpipes fit on the 550, would aftermarket m5 downpipes fit as well? Thanks for your responses .

[peter91118]

I wonder if the M5 exhaust manifolds would fit...

[Simple5]

Originally Posted by peter91118

I wonder if the M5 exhaust manifolds would fit...

AFAIK they do. The down pipes and manifolds.. it all boils down to tuning to maximize. A guy on the bms forums has secured a set and he was bugging Terry about the tuning. Not sure what came of that.

[550Reasons]

after searching around, 2010 - 03/2011 built date is flange style

04/2011 + is slip fit

Sadly I am 12/2010, so M5 DPs would not fit, was really hoping to do this swap too ...

[FenixMike]

Originally Posted by 550Reasons

after searching around, 2010 - 03/2011 built date is flange style

04/2011 + is slip fit

Sadly I am 12/2010, so M5 DPs would not fit, was really hoping to do this swap too ...

nothing an exhaust shop can't fix.

[peter91118]

Originally Posted by 550Reasons

after searching around, 2010 - 03/2011 built date is flange style

04/2011 + is slip fit

Sadly I am 12/2010, so M5 DPs would not fit, was really hoping to do this swap too ...

That just means you must do a complete M5 exhaust.

[550Reasons]

Originally Posted by peter91118

That just means you must do a complete M5 exhaust.

oh ? does it refer to the end side or the turbo side ? I thought it meant the turbo side, if its the end side then yes a shop can probably work with it

[VinoFiveFiddy]

Originally Posted by 550Reasons

after searching around, 2010 - 03/2011 built date is flange style

04/2011 + is slip fit

Sadly I am 12/2010, so M5 DPs would not fit, was really hoping to do this swap too ...

Mine is a 12/10 build date as well. but if we go with M5 downpipes and a full M5 exhaust, from what I'm reading that all will be well. I'm seriously considering this full swap. I just wonder what havoc it'll cause at the dealership if I have a warranty issue.

[747flyboy]

Just to clarify. I am 2011/1 Perfect fit Turbo side M5 downpipes coupled to full M5 Exhaust with minor exhaust shop modifications.

[VinoFiveFiddy]

Originally Posted by 747flyboy

Just to clarify. I am 2011/1 Perfect fit Turbo side M5 downpipes coupled to full M5 Exhaust with minor exhaust shop modifications.

How's that setup sounding?