N55 Head N54 Bottom End... Possible?

slick_dipstick · 04-23-2019, 02:23 PM

I have an n55 and want to do a single turbo upgrade but the issue is that n55 internals are pretty week. Cant make anything over 550hp until the crank goes kaput. Is it possible to do a bottom end swap with the n54 and install all the forged internals as well? Kinda like a 1.5jz. Has anyone done this? I would like some input.

Crazy idea but would like to try.

Kevin39 · 04-23-2019, 03:32 PM

There's plenty of N55s with over 550hp and plenty over 550whp.

Pladi · 04-23-2019, 03:34 PM

Off the top of my head the cooling and oiling galleries would probably not match ?

Ozzie335i · 04-23-2019, 03:49 PM

Why not just get stronger N55 rods? I have not heard of a broken crank or pistons on a properly running N55 on these threads. I recall mention of bent rods. Maybe tune related. Anyhow, what are your power aspirations sd? 600, 700, stupidity power? Anything > 600 is good for being among the cool N54 guys here, on a video racing a Vette, or blowing the engine up on a dyno. I am a few over 530 right now and feel that anything more will only be good for spinning the wheels in 4th gear. If that works, have at it.

slick_dipstick · 04-23-2019, 03:58 PM

Quote:

Originally Posted by Kevin39

There's plenty of N55s with over 550hp and plenty over 550whp.

Im sure there are. Just wondering if which avenue to take. I guess I could go with forged internal upgrade, but how much would that cost me and what would I need to change specifically?

slick_dipstick · 04-23-2019, 04:01 PM

Quote:

Originally Posted by Ozzie335i

Why not just get stronger N55 rods? I have not heard of a broken crank or pistons on a properly running N55 on these threads. I recall mention of bent rods. Maybe tune related. Anyhow, what are your power aspirations sd? 600, 700, stupidity power? Anything > 600 is good for being among the cool N54 guys here, on a video racing a Vette, or blowing the engine up on a dyno. I am a few over 530 right now and feel that anything more will only be good for spinning the wheels in 4th gear. If that works, have at it.

Well, I have a N55 x6 that I would love to push 600-ish on. I am currently FBO stage 2 pushing 400 hp on MHD. I love this beast and with its x-drive this thing would be a rocket. Just I heard that the cast internals are a weak link for these engines. I just aspire to make something like the SRT Jeeps out there.

Also, would you know any cheaper single turbo kits for n55?

E92n55slo · 04-23-2019, 04:12 PM

Quote:

Originally Posted by slick_dipstick

Quote:

Originally Posted by Ozzie335i

Why not just get stronger N55 rods? I have not heard of a broken crank or pistons on a properly running N55 on these threads. I recall mention of bent rods. Maybe tune related. Anyhow, what are your power aspirations sd? 600, 700, stupidity power? Anything > 600 is good for being among the cool N54 guys here, on a video racing a Vette, or blowing the engine up on a dyno. I am a few over 530 right now and feel that anything more will only be good for spinning the wheels in 4th gear. If that works, have at it.

Well, I have a N55 x6 that I would love to push 600-ish on. I am currently FBO stage 2 pushing 400 hp on MHD. I love this beast and with its x-drive this thing would be a rocket. Just I heard that the cast internals are a weak link for these engines. I just aspire to make something like the SRT Jeeps out there.

Also, would you know any cheaper single turbo kits for n55?

Mhd stage 2 derive making 400hp lmao more like 340hp

weehe126 · 04-23-2019, 04:18 PM

They have the same internals, so there would be no point.

slick_dipstick · 04-23-2019, 04:19 PM

Quote:

Originally Posted by E92n55slo

Mhd stage 2 derive making 400hp lmao more like 340hp

Well as advertised lol. 400 to the crank

slick_dipstick · 04-23-2019, 04:20 PM

Quote:

Originally Posted by weehe126

They have the same internals, so there would be no point.

But n54 has stronger forged internals. Correct?

slick_dipstick · 04-23-2019, 04:23 PM

Also, wondering if a n54 st bottom mount kit would fit on the n55

Kevin39 · 04-23-2019, 04:37 PM

Quote:

Originally Posted by slick_dipstick

Also, would you know any cheaper single turbo kits for n55?

Every N55 turbo kit is a single turbo kit so I guess a cheap one would be a Pure Stage 1 but it's not going to get you anywhere near 600hp. I don't even know what all is compatible with an X6. Almost everyone here has an E9X or a 1 series.

Honestly, that car is so heavy that I don't think it's ever going to be the rocket you want it to be. Just a heads up that I would think twice before dumping a ton of money in to it.

I would just throw a pure stage 2 on it and enjoy it. What are your tuning options for that car? MHD, BM3, just a JB4?

slick_dipstick · 04-23-2019, 04:57 PM

Quote:

Originally Posted by Kevin39

Every N55 turbo kit is a single turbo kit so I guess a cheap one would be a Pure Stage 1 but it's not going to get you anywhere near 600hp. I don't even know what all is compatible with an X6. Almost everyone here has an E9X or a 1 series.

Honestly, that car is so heavy that I don't think it's ever going to be the rocket you want it to be. Just a heads up that I would think twice before dumping a ton of money in to it.

I would just throw a pure stage 2 on it and enjoy it. What are your tuning options for that car? MHD, BM3, just a JB4?

So just go the pure turbo route? Probably would be the most economical route. Do they offer anything above stage 2?

Its pretty quick now! I mean keep up with stage one MHD 335is. On a straight line this thing beats STI's no problem. I currently run stage 2 mhd so that answers your last question

biz77 · 04-23-2019, 05:53 PM

Trade it in for a XDrive50i... Ethanol blend tune, downpipes and be done. It will run well into the 11's and rip to 60 in just over 3 seconds. You will be spending way more money to get an N55 to put up the same numbers.

Turbod · 04-23-2019, 06:50 PM

Quote:

Originally Posted by slick_dipstick

So just go the pure turbo route? Probably would be the most economical route. Do they offer anything above stage 2?

Its pretty quick now! I mean keep up with stage one MHD 335is. On a straight line this thing beats STI's no problem. I currently run stage 2 mhd so that answers your last question

If you want to keep the car go PS2 and be happy that it is faster than stock.

Quote:

Originally Posted by biz77

Trade it in for a XDrive50i... Ethanol blend tune, downpipes and be done. It will run well into the 11's and rip to 60 in just over 3 seconds. You will be spending way more money to get an N55 to put up the same numbers.

I would go for the X3M. 2015 X6 is pretty expensive so the X3M isn't that much of a stretch.

weehe126 · 04-23-2019, 06:54 PM

Quote:

Originally Posted by slick_dipstick

But n54 has stronger forged internals. Correct?

No, they have the same rods and pistons which are the failure points. Crank maybe forged but no one is breaking N55 cranks.

biz77 · 04-23-2019, 07:05 PM

Quote:

Originally Posted by Turbod

If you want to keep the car go PS2 and be happy that it is faster than stock.

I would go for the X3M. 2015 X6 is pretty expensive so the X3M isn't that much of a stretch.

2015 - 2016 X6 Xdrive 50i goes for around $40K
2020 X3M will start at $71K

Seems like quite a stretch to me

slick_dipstick · 04-23-2019, 07:39 PM

Quote:

Originally Posted by biz77

Quote:

Originally Posted by Turbod

If you want to keep the car go PS2 and be happy that it is faster than stock.

I would go for the X3M. 2015 X6 is pretty expensive so the X3M isn't that much of a stretch.

2015 - 2016 X6 Xdrive 50i goes for around $40K
2020 X3M will start at $71K

Seems like quite a stretch to me

Lol I know right. Plus I heard bad things about the 4.4 in the 50i models. Heard it was problematic.

I don't want to have to go through selling my car and finding and buying a 50i model. Just doesn't make sense in my books.

biz77 · 04-23-2019, 08:05 PM

Quote:

Originally Posted by slick_dipstick

Lol I know right. Plus I heard bad things about the 4.4 in the 50i models. Heard it was problematic.

I don't want to have to go through selling my car and finding and buying a 50i model. Just doesn't make sense in my books.

Original N63 was very problematic. N63TU seems to have fewer issues than the N55.

You don't want to go through the trouble of selling your car, but you are willing to pull out a functioning engine so you can Frankenstein two different halves of an engine together and then put on a large turbo and supporting modifications? I get it.

Stage 1 (reflash only) N63TUs are putting out 525 WHP and around 600 LBS. FT. Torque on 93 octane. That is N55 with Pure Stage 2 on E50 numbers.

bbnks2 · 04-23-2019, 09:07 PM

No, you cannot put an n55 head on an n54 bottom end and there would be 0 reason to do so.

You can just put an n54 crank into the n55 if you want to. The n54 pistons and rods are pretty much the same as n55 and you're not breaking a crank at 600whp. Just slap a stage 3 turbo onto the n55 you have and swap in a used motor if it blows. Forged internals is a waste of money for 600whp.

Turbod · 04-24-2019, 12:55 PM

Quote:

Originally Posted by biz77

2015 - 2016 X6 Xdrive 50i goes for around $40K
2020 X3M will start at $71K

Seems like quite a stretch to me

I ran with the assumption of his join date being in 2016 and his car being a 2015 that he bought either new or almost new. The base model was $56k.

TheGoodTheBadTheUgly · 04-25-2019, 05:18 PM

I don't see how a crank would break at arround 550Hp with a proper tune. Unless you are planning on running the car with a bunch of cylinder corrections!

Switching the bottom end is too complicated and would require machining which probably is more painful then trying to stick a s55 in there.

04-23-2019, 02:23 PM	#1
slick_dipstick New Member 34 Rep 25 Posts Drives: 2015 X6 35i Join Date: Aug 2016 Location: Asheville, NC iTrader: (0)	N55 Head N54 Bottom End... Possible? I have an n55 and want to do a single turbo upgrade but the issue is that n55 internals are pretty week. Cant make anything over 550hp until the crank goes kaput. Is it possible to do a bottom end swap with the n54 and install all the forged internals as well? Kinda like a 1.5jz. Has anyone done this? I would like some input. Crazy idea but would like to try. Last edited by slick_dipstick; 04-23-2019 at 02:30 PM..
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04-23-2019, 03:32 PM	#2
Kevin39 Lieutenant 164 Rep 411 Posts Drives: 2011 E90 N55 Join Date: Feb 2016 Location: Indiana iTrader: (0)	There's plenty of N55s with over 550hp and plenty over 550whp.
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04-23-2019, 03:34 PM	#3
Pladi Lieutenant Colonel 723 Rep 1,753 Posts Drives: 2011 335i xdrive Join Date: Nov 2017 Location: Waterloo, ON Canada iTrader: (0)	Off the top of my head the cooling and oiling galleries would probably not match ?
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04-23-2019, 03:49 PM	#4
Ozzie335i Lieutenant Colonel 662 Rep 1,532 Posts Drives: 2011 335i Join Date: Aug 2014 Location: DFW iTrader: (1)	Why not just get stronger N55 rods? I have not heard of a broken crank or pistons on a properly running N55 on these threads. I recall mention of bent rods. Maybe tune related. Anyhow, what are your power aspirations sd? 600, 700, stupidity power? Anything > 600 is good for being among the cool N54 guys here, on a video racing a Vette, or blowing the engine up on a dyno. I am a few over 530 right now and feel that anything more will only be good for spinning the wheels in 4th gear. If that works, have at it.
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04-23-2019, 04:18 PM	#8
weehe126 Brigadier General 1195 Rep 3,234 Posts Drives: 2017 340i Join Date: Apr 2014 Location: San Antonio iTrader: (2)	They have the same internals, so there would be no point.
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04-23-2019, 04:23 PM	#11
slick_dipstick New Member 34 Rep 25 Posts Drives: 2015 X6 35i Join Date: Aug 2016 Location: Asheville, NC iTrader: (0)	Also, wondering if a n54 st bottom mount kit would fit on the n55
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04-23-2019, 05:53 PM	#14
biz77 Captain 216 Rep 633 Posts Drives: 2021 X3 M40i Join Date: Aug 2010 Location: Spokane, WA iTrader: (4)	Trade it in for a XDrive50i... Ethanol blend tune, downpipes and be done. It will run well into the 11's and rip to 60 in just over 3 seconds. You will be spending way more money to get an N55 to put up the same numbers.
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04-23-2019, 09:07 PM	#20
bbnks2 Colonel 1228 Rep 2,030 Posts Drives: 135i N55 Join Date: Jan 2017 Location: NY iTrader: (0)	No, you cannot put an n55 head on an n54 bottom end and there would be 0 reason to do so. You can just put an n54 crank into the n55 if you want to. The n54 pistons and rods are pretty much the same as n55 and you're not breaking a crank at 600whp. Just slap a stage 3 turbo onto the n55 you have and swap in a used motor if it blows. Forged internals is a waste of money for 600whp.
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04-25-2019, 05:18 PM	#22
TheGoodTheBadTheUgly Captain 288 Rep 698 Posts Drives: 2011 E90 335i xDrive Join Date: Feb 2018 Location: Gatineau iTrader: (0)	I don't see how a crank would break at arround 550Hp with a proper tune. Unless you are planning on running the car with a bunch of cylinder corrections! Switching the bottom end is too complicated and would require machining which probably is more painful then trying to stick a s55 in there. __________________ TOTALED \| 2011 E90 335i xDrive - BMS Cold Air Intake - ETS Charge Pipe - ETS 7" FMIC - MHD Stage 2+ - GFB DV+ - PE Mod - VRSF Catless Downpipe - xDelete - xHP Stage 3 2015 E84 X1 35i M-Sport
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