N52 Single Turbo Options

tom.gnade · 12-16-2016, 07:12 PM

So we now know the N52 can handle a turbo just fine. Would it be possible, then, to take a twin-scroll turbo from an N55 and make a relatively inexpensive upgrade for the N52 that pushes 300+/- whp at low boost without messing with the injectors or fuel pump? Used N55 low-mileage turbos and intercoolers are cheap on car-parts.

CobraMarty · 12-17-2016, 05:11 AM

Yes and no not without some mods.
I have a N52 head, complete engine on the stand and all the N55 turbo pieces.

-The N55 turbo manifold has a couple of bolt holes in different location than the N52 head. You could drill the N55 manifold on those couple of holes or move the studs on the N52 head.
-The exhaust ports are in the same location but the exhaust gaskets on the N55 are smaller than the N52. It should not be a problem but will require some spacer rings on the N55 exhaust so you can use the bigger N52 exhaust gaskets.
-The water jacket outlet on the N52 is right where the N55 turbo sits so it will need to have a 90* off it to snake around the turbo.
-A boost/wastegate controller, and maybe a blow off valve.
-You will need bigger injectors and a BPC tune or supplemental port injectors added. The fuel pump IDK, might need a booster pump.

Yep the parts off the N55 are very inexpensive and shouldn't be overlooked.

JuniorB · 12-17-2016, 07:06 AM

When you look at a lot of pictures, that only tells have the story. Cutting and making a factory turbo kit for a non turbo is worthless,it takes twice as much time to make it fit. No one discloses the countless hours it takes to fab these prices to make them fit right instead of barely. The hours of tinkering where and what to use to lube the turbos,let alone the intake and ic piping. Not an easy job by any means. Bpc's kit is at a coservitive numbers. For the time and money venders are selling single kits for,I would rather have the supercharger kit and tuned properly. That kit has hidden power,it just needs to be tuned properly. Just my 02

CobraMarty · 12-17-2016, 07:23 AM

The N55 will require drilling 4 holes in the mounting flange and 6 small machined rings to adapt the N52 exhaust gasket to the N55 turbo flange.
That's probably beyond most's capabilities.

Looking at pictures is not the same as looking at the actual pieces in hand. It's like Legos for adults.

The SC kit has a terrible boost curve. Take a look at that before you make your comparison and decision between the Turbo and SC. And look at parasitic loss, charge intake air temps.

CobraMarty · 12-17-2016, 08:47 AM

I had only looked briefly at the exhaust and exhaust gaskets before.

N55 exhaust tube OD=38.5mm=1.50", exhaust gasket ID=39.0mm OD=49.0mm
N52 exhaust tube OD=41.0mm=1.61", exhaust gasket ID=40.7mm OD=51.5mm

The plan could be to 'sleeve' the N55 exhaust tube with chrome moly 4130 tubing with 1.625" OD 0.083" wall = 1.459" ID. Could heat and install or minor machining to fit.

So that is not an issue or problem.
N55 exhaust manifold and turbo are cheap, used Ebay $375-550 to $1000. Stock N55 down pipes are also available which yet to be seen might bolt to stock exhaust.

JuniorB · 12-18-2016, 10:14 AM

The sc may haven't have a great curve,but it follows a stock curve just slightly. That kit only put out 60-70 rwh,which isn't much if your bolting it on a stock 325. That kit lacks a lot of hardware that a turbo has. It that kit had headers,injectors,a free flow exhaust,and the right fueling, and a n54 intake,it could very well make excellent numbers. The sc kits for an m3 makes substancial power. A stock n52 is restricted as we've seen You can't really compare the two,as the Bpc n52 has better na numbers to start with. I'm sure if someone was looking to spend some money,you could send n52 flanges to a n54 single manufacture and have them make hot parts,a turbo with just oil ports,and aftermarket cp,and ic.

CobraMarty · 12-22-2016, 03:54 PM

Today had some time to look closer at the N55 turbo exhaust manifold flange bolting to the N52 head.

-All 8 upper studs on the N52 head are just barely 1/16" off. BMW moved them just this slight amount to prevent the easy bolting of a N55 turbo on to a N52 head. So will need to drill the hole off center slightly to fit. 'Oval out' the hole.
-The middle 2 studs on the bottom that are raised are in the wrong location. Can either drill the N55 flange for these 4 higher studs but might not be able to get the nut on to tighten. Better to drill and thread the head to move the 4 studs lower.

Today I bought a used bad N52 head for $70 that I can drill where I need to and see if it hits a water jacket. There looks to be NO water in this area. But I will drill it and then drill even bigger just to be sure.

Last is the exhaust gasket size but that can be solved with sleeving the N55 exhaust slightly larger to fit the N52 exhaust gasket.

JuniorB · 12-22-2016, 05:50 PM

I think this topic came up before,I was looking at this route also about a year ago. Same conclusion with the bolt holes. I thought about enlarging the holes,as long as the ports with gaskets seats,you should be good. I believe rub turbo may have flanges with the ccorrectbolt pattern. Are you thinking of pulling this off????

CobraMarty · 12-22-2016, 07:51 PM

I have all the pieces needed to do it. Just gotta put all the 'LEGO' pieces together.
I have a N54 supplemental fuel rail for 6 axillary injectors and control with a AIC controller.
Probably at some point have BPC tune it.

CobraMarty · 12-25-2016, 11:17 AM

The upper N55 turbo exhaust manifold flange holes need to be moved about 1/16-2/32", all in slightly different directions. The easiest way to locate the correct position is it use a N52 header flange as a template and drill/mill the new holes. I've asked BPC if I can buy a flange from them or I can buy a used N52 exhaust and cut off the pipes/merge/cat off and leave just the flange and use that for the template.

I already have a RB N54/55 exhaust flange to use as the template for the bottom 4 holes that need to be drilled in the head.

I will probably use the N52 flange to use to template the RB N54/55 flange I have so it will be a N52/N54/N55 exhaust flange.
Then I will make a drill jig that will bolt on to the head for drilling the lower 4 holes in the head.

It sounds all mix-match jumble but it really is quite straight forward and simple.

JuniorB · 12-25-2016, 01:00 PM

I thought about the same thing when I fist saw the n55 coming out. So many ideas ran thru my head with this motor not knowing what I wanted out of it. Bpc ran a tread about fitting a n55 manifold on a n52. I was thinking of a rear turbo system with a comp turbo to lessen the complex of cooling. It's not my dd,so this wouldn't be an issue. I've settled on running the nitrous and seeing how far I can take it till I sell of all my awd parts to continue the n54 swap.

STR8-6IX · 12-25-2016, 03:25 PM

Quote:

Originally Posted by JJenE92

As I understand it the N52/N51's internals aren't reinforced enough to handle turbos, supercharging is the only way we're going to get forced induction on this platform and even that seems like a pipe dream.

thats bullshit - lots of people were convinced of this and its not true. We have someone on here with a 400hp turbo n52 and he has no issues with engine strength

dstrickland · 12-25-2016, 07:17 PM

Quote:

Originally Posted by 6IX-F10-N52

Quote:

Originally Posted by JJenE92

As I understand it the N52/N51's internals aren't reinforced enough to handle turbos, supercharging is the only way we're going to get forced induction on this platform and even that seems like a pipe dream.

thats bullshit - lots of people were convinced of this and its not true. We have someone on here with a 400hp turbo n52 and he has no issues with engine strength

Your replying to a post that was written nearly 5 years ago....

JuniorB · 12-25-2016, 09:23 PM

Sounds great,love to see the progress,I have pics of what I've done on my nitrous,but don't know how to load pics

EvilSideOfGood · 08-09-2018, 12:07 PM

Quote:

Originally Posted by CobraMarty

The upper N55 turbo exhaust manifold flange holes need to be moved about 1/16-2/32", all in slightly different directions. The easiest way to locate the correct position is it use a N52 header flange as a template and drill/mill the new holes. I've asked BPC if I can buy a flange from them or I can buy a used N52 exhaust and cut off the pipes/merge/cat off and leave just the flange and use that for the template.

I already have a RB N54/55 exhaust flange to use as the template for the bottom 4 holes that need to be drilled in the head.

I will probably use the N52 flange to use to template the RB N54/55 flange I have so it will be a N52/N54/N55 exhaust flange.
Then I will make a drill jig that will bolt on to the head for drilling the lower 4 holes in the head.

It sounds all mix-match jumble but it really is quite straight forward and simple.

How about cutting n55 flange off the manifold and welding the pipes on a n52 flange? That saves you all the hassle with drilling. And Were you able to finish the project?

CobraMarty · 08-24-2018, 05:32 PM

I got some renewed interest/effort/energy into this project.

I have a N52 engine sitting on an engine stand. So if the N55 'turbofold' is bolted to the N52 head, the compressor housing hits the n52 block, or at least one mounting boss that sticks out from the block. It looks like if the N55 Turbofold is spaced out 1" everything will clear. I ordered some longer 7mm 1.0 bolts and 1" HPDE to make the spacer. Will probably just use washers to space out 1" to measure everything.

I will drill out the holes in the N55 turbofold slightly where needed to fit the N52 bolt pattern/spacing.
The 1" spacer can accept the N55 gasket and on the head side just use a flat gasket.

The bolts shipped. Next week I will bolt it together and see where the next hurdle is.
IDK if moving the N55 turbofold out 1" will cause a 'new issue' and have the compressor hit the frame or something. One bridge at a time.

CobraMarty · 08-24-2018, 05:42 PM

Here you can see the 'boss' sticking out from the block just in front of the water pipe.
IDK what bolts to this boss if anything. Maybe could just cut it off but the 1" spacer will clear the boss and give more room for the water pipe to be modified and fit.

hassmaschine · 08-24-2018, 06:08 PM

I think you could remove it. Its not used for anything on most N52s.

cwlo · 08-24-2018, 06:35 PM

If you cut it, remember its magnesium.....i.e flammable.

hassmaschine · 08-24-2018, 06:52 PM

Ah, true. Not feasible with a grinder.

CobraMarty · 08-24-2018, 07:02 PM

Darn, the angle grinder is my tool of choice.

Another question- Just below that boss is a plug. It is held in with a bolt. What is it for? Is it oil supply or oil drain? Wish wish.

hassmaschine · 08-24-2018, 07:54 PM

Probably an oil passage. They drill holes where its not feasible to cast, then plug the openings.

12-16-2016, 07:12 PM	#67
tom.gnade Apex Forged 19", AA headers, MILVs, 3IM, Euro Intake, Swift Spec-R 87 Rep 255 Posts Drives: 2013 328i coupe Join Date: May 2016 Location: Forest Hill, MD iTrader: (1) Garage List 2013 BMW 328i [0.00]	So we now know the N52 can handle a turbo just fine. Would it be possible, then, to take a twin-scroll turbo from an N55 and make a relatively inexpensive upgrade for the N52 that pushes 300+/- whp at low boost without messing with the injectors or fuel pump? Used N55 low-mileage turbos and intercoolers are cheap on car-parts.
	Appreciate 0 Quote

12-17-2016, 05:11 AM	#68
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Yes and no not without some mods. I have a N52 head, complete engine on the stand and all the N55 turbo pieces. -The N55 turbo manifold has a couple of bolt holes in different location than the N52 head. You could drill the N55 manifold on those couple of holes or move the studs on the N52 head. -The exhaust ports are in the same location but the exhaust gaskets on the N55 are smaller than the N52. It should not be a problem but will require some spacer rings on the N55 exhaust so you can use the bigger N52 exhaust gaskets. -The water jacket outlet on the N52 is right where the N55 turbo sits so it will need to have a 90* off it to snake around the turbo. -A boost/wastegate controller, and maybe a blow off valve. -You will need bigger injectors and a BPC tune or supplemental port injectors added. The fuel pump IDK, might need a booster pump. Yep the parts off the N55 are very inexpensive and shouldn't be overlooked.
	Appreciate 0 Quote

12-17-2016, 07:06 AM	#69
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	When you look at a lot of pictures, that only tells have the story. Cutting and making a factory turbo kit for a non turbo is worthless,it takes twice as much time to make it fit. No one discloses the countless hours it takes to fab these prices to make them fit right instead of barely. The hours of tinkering where and what to use to lube the turbos,let alone the intake and ic piping. Not an easy job by any means. Bpc's kit is at a coservitive numbers. For the time and money venders are selling single kits for,I would rather have the supercharger kit and tuned properly. That kit has hidden power,it just needs to be tuned properly. Just my 02
	Appreciate 0 Quote

12-17-2016, 07:23 AM	#70
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	The N55 will require drilling 4 holes in the mounting flange and 6 small machined rings to adapt the N52 exhaust gasket to the N55 turbo flange. That's probably beyond most's capabilities. Looking at pictures is not the same as looking at the actual pieces in hand. It's like Legos for adults. The SC kit has a terrible boost curve. Take a look at that before you make your comparison and decision between the Turbo and SC. And look at parasitic loss, charge intake air temps.
	Appreciate 0 Quote

12-17-2016, 08:47 AM	#71
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	I had only looked briefly at the exhaust and exhaust gaskets before. N55 exhaust tube OD=38.5mm=1.50", exhaust gasket ID=39.0mm OD=49.0mm N52 exhaust tube OD=41.0mm=1.61", exhaust gasket ID=40.7mm OD=51.5mm The plan could be to 'sleeve' the N55 exhaust tube with chrome moly 4130 tubing with 1.625" OD 0.083" wall = 1.459" ID. Could heat and install or minor machining to fit. So that is not an issue or problem. N55 exhaust manifold and turbo are cheap, used Ebay $375-550 to $1000. Stock N55 down pipes are also available which yet to be seen might bolt to stock exhaust.
	Appreciate 0 Quote

12-18-2016, 10:14 AM	#72
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	The sc may haven't have a great curve,but it follows a stock curve just slightly. That kit only put out 60-70 rwh,which isn't much if your bolting it on a stock 325. That kit lacks a lot of hardware that a turbo has. It that kit had headers,injectors,a free flow exhaust,and the right fueling, and a n54 intake,it could very well make excellent numbers. The sc kits for an m3 makes substancial power. A stock n52 is restricted as we've seen You can't really compare the two,as the Bpc n52 has better na numbers to start with. I'm sure if someone was looking to spend some money,you could send n52 flanges to a n54 single manufacture and have them make hot parts,a turbo with just oil ports,and aftermarket cp,and ic.
	Appreciate 0 Quote

12-22-2016, 03:54 PM	#73
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Today had some time to look closer at the N55 turbo exhaust manifold flange bolting to the N52 head. -All 8 upper studs on the N52 head are just barely 1/16" off. BMW moved them just this slight amount to prevent the easy bolting of a N55 turbo on to a N52 head. So will need to drill the hole off center slightly to fit. 'Oval out' the hole. -The middle 2 studs on the bottom that are raised are in the wrong location. Can either drill the N55 flange for these 4 higher studs but might not be able to get the nut on to tighten. Better to drill and thread the head to move the 4 studs lower. Today I bought a used bad N52 head for $70 that I can drill where I need to and see if it hits a water jacket. There looks to be NO water in this area. But I will drill it and then drill even bigger just to be sure. Last is the exhaust gasket size but that can be solved with sleeving the N55 exhaust slightly larger to fit the N52 exhaust gasket.
	Appreciate 0 Quote

12-22-2016, 05:50 PM	#74
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	I think this topic came up before,I was looking at this route also about a year ago. Same conclusion with the bolt holes. I thought about enlarging the holes,as long as the ports with gaskets seats,you should be good. I believe rub turbo may have flanges with the ccorrectbolt pattern. Are you thinking of pulling this off????
	Appreciate 0 Quote

12-22-2016, 07:51 PM	#75
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	I have all the pieces needed to do it. Just gotta put all the 'LEGO' pieces together. I have a N54 supplemental fuel rail for 6 axillary injectors and control with a AIC controller. Probably at some point have BPC tune it.
	Appreciate 0 Quote

12-25-2016, 11:17 AM	#76
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	The upper N55 turbo exhaust manifold flange holes need to be moved about 1/16-2/32", all in slightly different directions. The easiest way to locate the correct position is it use a N52 header flange as a template and drill/mill the new holes. I've asked BPC if I can buy a flange from them or I can buy a used N52 exhaust and cut off the pipes/merge/cat off and leave just the flange and use that for the template. I already have a RB N54/55 exhaust flange to use as the template for the bottom 4 holes that need to be drilled in the head. I will probably use the N52 flange to use to template the RB N54/55 flange I have so it will be a N52/N54/N55 exhaust flange. Then I will make a drill jig that will bolt on to the head for drilling the lower 4 holes in the head. It sounds all mix-match jumble but it really is quite straight forward and simple.
	Appreciate 0 Quote

12-25-2016, 01:00 PM	#77
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	I thought about the same thing when I fist saw the n55 coming out. So many ideas ran thru my head with this motor not knowing what I wanted out of it. Bpc ran a tread about fitting a n55 manifold on a n52. I was thinking of a rear turbo system with a comp turbo to lessen the complex of cooling. It's not my dd,so this wouldn't be an issue. I've settled on running the nitrous and seeing how far I can take it till I sell of all my awd parts to continue the n54 swap.
	Appreciate 0 Quote

12-25-2016, 09:23 PM	#80
JuniorB Major 185 Rep 1,017 Posts Drives: 07 e60 525 N54 Join Date: Mar 2016 Location: Rhode Island iTrader: (0)	Sounds great,love to see the progress,I have pics of what I've done on my nitrous,but don't know how to load pics
	Appreciate 0 Quote

08-24-2018, 05:32 PM	#82
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	I got some renewed interest/effort/energy into this project. I have a N52 engine sitting on an engine stand. So if the N55 'turbofold' is bolted to the N52 head, the compressor housing hits the n52 block, or at least one mounting boss that sticks out from the block. It looks like if the N55 Turbofold is spaced out 1" everything will clear. I ordered some longer 7mm 1.0 bolts and 1" HPDE to make the spacer. Will probably just use washers to space out 1" to measure everything. I will drill out the holes in the N55 turbofold slightly where needed to fit the N52 bolt pattern/spacing. The 1" spacer can accept the N55 gasket and on the head side just use a flat gasket. The bolts shipped. Next week I will bolt it together and see where the next hurdle is. IDK if moving the N55 turbofold out 1" will cause a 'new issue' and have the compressor hit the frame or something. One bridge at a time.
	Appreciate 1 Phyrexia502.50 Quote

08-24-2018, 05:42 PM	#83
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Here you can see the 'boss' sticking out from the block just in front of the water pipe. IDK what bolts to this boss if anything. Maybe could just cut it off but the 1" spacer will clear the boss and give more room for the water pipe to be modified and fit.
	Appreciate 1 Phyrexia502.50 Quote

08-24-2018, 06:08 PM	#84
hassmaschine Major General 3966 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	I think you could remove it. Its not used for anything on most N52s.
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08-24-2018, 06:35 PM	#85
cwlo Private First Class 84 Rep 110 Posts Drives: 04 m3 Join Date: Dec 2017 Location: Chicago iTrader: (0)	If you cut it, remember its magnesium.....i.e flammable.
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08-24-2018, 06:52 PM	#86
hassmaschine Major General 3966 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	Ah, true. Not feasible with a grinder.
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08-24-2018, 07:02 PM	#87
CobraMarty Major 619 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Darn, the angle grinder is my tool of choice. Another question- Just below that boss is a plug. It is held in with a bolt. What is it for? Is it oil supply or oil drain? Wish wish.
	Appreciate 0 Quote

08-24-2018, 07:54 PM	#88
hassmaschine Major General 3966 Rep 7,215 Posts Drives: "NBO" 330i Join Date: Jun 2014 Location: earth iTrader: (0)	Probably an oil passage. They drill holes where its not feasible to cast, then plug the openings.
	Appreciate 0 Quote