[pjr710]

Originally Posted by Edris335i

i've heard that they're pretty much hit or miss kits and that their turbos can go out within a few hundred miles.

yea to me thats insane ... and single turbo seems like the way to go MAINLY because of the rattle fix. If i have to change my turbos .. I will never want to do it again

[Torgus]

Rattle repair kits are ok I guess. It's just massive labor to take the turbos in and out and still have old ass turbos at the end of the day.

speedtech N54 cast bottom mount ST $2,900 with turbo. Should sell like hot cakes: https://www.speedtech.com/bmw-n54

[b92]

Originally Posted by Torgus

Rattle repair kits are ok I guess. It's just massive labor to take the turbos in and out and still have old ass turbos at the end of the day.

speedtech N54 cast bottom mount ST $2,900 with turbo. Should sell like hot cakes: https://www.speedtech.com/bmw-n54

oh HOT DAMN. That's a hell of a price, I wonder if that price includes a Garrett or BW.

[Edris335i]

Originally Posted by pjr710

yea to me thats insane ... and single turbo seems like the way to go MAINLY because of the rattle fix. If i have to change my turbos .. I will never want to do it again

yeah that's the exact same reason why i went with a single instead of hybrid twins. i never wanted to hear that terrible rattle again

[Torgus]

Originally Posted by b92

oh HOT DAMN. That's a hell of a price, I wonder if that price includes a Garrett or BW.

A Decent Garret GTX is around $2,500 retail. Nothing wrong with the BW SX series. Plenty of cars use them and make great numbers. They are also affordable. If you want a larger or smaller turbo it hits the wallet a lot less under 1k. If I want a different precision I pay like 2k.

Originally Posted by Edris335i

yeah that's the exact same reason why i went with a single instead of hybrid twins. i never wanted to hear that terrible rattle again

Amen. Single also give you the most power on pump gas, by far.

[pjr710]

Originally Posted by Torgus

Rattle repair kits are ok I guess. It's just massive labor to take the turbos in and out and still have old ass turbos at the end of the day.

speedtech N54 cast bottom mount ST $2,900 with turbo. Should sell like hot cakes: https://www.speedtech.com/bmw-n54

and these will eliminate rattle?

I guess i'm confused at why the ST options do it .. but twins don't ... is it b/c all ST kits have external gates?

edit: this kit might be the tits btw! .... gotta do some research on it ... seems badass!

[Torgus]

Originally Posted by pjr710

and these will eliminate rattle?

I guess i'm confused at why the ST options do it .. but twins don't ... is it b/c all ST kits have external gates?

You got it.

[pjr710]

Originally Posted by Torgus

You got it.

I don’t understand tho. Can twins not have external WGS?

[Torgus]

Originally Posted by pjr710

I don’t understand tho. Can twins not have external WGS?

Twins can, just not easily on this platform. Not without an amazing amount of work which would not be worth the $$$. After all that work you could buy a single turbo and be better off.

[pjr710]

Originally Posted by Torgus

Twins can, just not easily on this platform. Not without an amazing amount of work which would not be worth the $$$. After all that work you could buy a single turbo and be better off.

gotcha

Originally Posted by Torgus

speedtech N54 cast bottom mount ST $2,900 with turbo. Should sell like hot cakes: https://www.speedtech.com/bmw-n54

That kit is so clean looking...certainly makes going single instead of upgrading twins much more appetizing.

With bottom mounts (and single conversions in general) are "burnt up" O2s still a thing? Or has that been corrected one way or another (aside from going with AGV or NTK O2s, etc.?)

What are you single turbo guys doing for boost control? JB4, BoostBox, some other form of EBC/MBC/etc.?

[Torgus]

Originally Posted by FCobra94

That kit is so clean looking...certainly makes going single instead of upgrading twins much more appetizing.

With bottom mounts (and single conversions in general) are "burnt up" O2s still a thing? Or has that been corrected one way or another (aside from going with AGV or NTK O2s, etc.?)

What are you single turbo guys doing for boost control? JB4, BoostBox, some other form of EBC/MBC/etc.?

Great questions. No more burned up 02s with either the ADV sensors(which I use) or the NTKs. People have 30k+ miles on both, no problems.


Boostbox, from Motiv, is the cheapest and easiest form of ST boost control imo. This lets you be 'flash only'. You can also get their ethanol fuel content sensor and let the tune self adjust based on your E85 content %. So no more loading different maps like a 93 map, E50 map E85 map. It adjusts your tune all on the fly based on your ethanol content.


A single makes the most sense for a variety of reasons on the N54. A single will also let you put down the most power/HP, and more importantly, the most power on pump gas for those of us(me) who has little to no E85 access.

[pjr710]

Originally Posted by Torgus

Great questions. No more burned up 02s with either the ADV sensors(which I use) or the NTKs. People have 30k+ miles on both, no problems.


Boostbox, from Motiv, is the cheapest and easiest form of ST boost control imo. This lets you be 'flash only'. You can also get their ethanol fuel content sensor and let the tune self adjust based on your E85 content %. So no more loading different maps like a 93 map, E50 map E85 map. It adjusts your tune all on the fly based on your ethanol content.


A single makes the most sense for a variety of reasons on the N54. A single will also let you put down the most power/HP, and more importantly, the most power on pump gas for those of us(me) who has little to no E85 access.

not to hijack or divert this question .. but how does more power actually get created on pump?

such as .. how could you make more power on pump from a ST than a twin? Is it because the twins would get too hot or something related to temps like that?

[Torgus]

Originally Posted by pjr710

not to hijack or divert this question .. but how does more power actually get created on pump?

such as .. how could you make more power on pump from a ST than a twin? Is it because the twins would get too hot or something related to temps like that?

Exactly.

The twins end up out of their efficiency range sooner and start to blow hot air than most of the single turbo set ups on this platform. The hotter the air the more likely to cause knock or predetonation.

Meth helps chemically cool the air and increases the octane rating so it allows for more boost. E85 is very resistant to knock. There are your solutions if you want to upgrade from pump 91/93. The only other solution is use a larger laggier turbo which will blow cooler air.

The larger sized turbo will not heat the air up as much as twins on this platform. So you will be able to make more HP than stock/upgraded twins if both are using pump fuel.

This is of course all assuming you are using a larger size single turbo. They make smaller single turbos as well which would heat the air up more. You pick the turbo based on your HP goal. If you just want say 500whp on 93 you pick a different sized turbo than it you want to make 800whp.

A 6466 is rated as a 900hp turbo and flows 90 lbs/min. Unfortunately no one gives compressor maps or flow ratings etc. for upgraded stock frame size turbos. So it's not as easy to compare them to a single on paper.

This is kind of the easy simple answer fwiw.

[pjr710]

Yea very good to know and glad i was on the right track.

I feel like I’m in a race against time w my car. I have 120k on it. All highway but I’m starting to wonder if upgrading is in the works or if the time has passed for me.

[teknic90]

Originally Posted by pjr710

Yea very good to know and glad i was on the right track.

I feel like I’m in a race against time w my car. I have 120k on it. All highway but I’m starting to wonder if upgrading is in the works or if the time has passed for me.

Been following this thread and I am in the same boat, about 120k and wondering if it's worth it at this point. Maybe someone in our shoes with higher mileage and ST can chime in.

[pjr710]

Originally Posted by teknic90

Been following this thread and I am in the same boat, about 120k and wondering if it's worth it at this point. Maybe someone in our shoes with higher mileage and ST can chime in.

yea for sure .. i was googling today and i saw someone on another forum say they had a 300k ST n54 and was fine lol.

people were saying it comes down to the health of the motor (oil changes, etc)

but I def wanna know! also FWIW Jake Spence on YT has his 135 .. and he blew a motor that had 120k (not sure why) and replaced it with a 100k one I think. And I believe the 120k was pretty abused and might have blown for a reason other than just normal failure.

[Torgus]

Mileage does not seem to affect the HP these motors can hold. You do the maintenance you are fine. Twins create TONS of low end tq. Low end TQ bends rods and is MUCH more stressful on the engine than a ST which creates power in the higher RPMs.

Jake was running twins FULLY maxed out. They were blowing hot ass air. He even touches on this in his YT video and is one of the reasons he switched to a single turbo. He felt it would be more reliable with his new used engine and be able to make more HP. Which I agree. Twins on the ragged edge of the compressor map(which does not exist) or a single well within it's power range and compressor map.

The only people who hit high numbers on twins are the vendors. No one has come close to VTTs numbers for instance.

[nissubaru]

Originally Posted by Torgus

Twins can, just not easily on this platform. Not without an amazing amount of work which would not be worth the $$$. After all that work you could buy a single turbo and be better off.

I can only imagine what would need to be done. On this platform it might even be impossible. To go externally gated you need a way to lock the stock wastegate closed and then add an external wastegate before the turbo but after the header. Since our exhaust manifolds consist of the turbo I'm not so sure how it could be done.

However, on Subarus you replace the "up pipe" with an external wastegate ready up pipe and either weld the internal wastegate shut or there are companies that sell brackets to hold it shut.

Its a little easier to picture on that platform, but yeah I would say it's probably not worth it if it's even possible to go EWG on twins

[pjr710]

Originally Posted by Torgus

Mileage does not seem to affect the HP these motors can hold. You do the maintenance you are fine. Twins create TONS of low end tq. Low end TQ bends rods and is MUCH more stressful on the engine than a ST which creates power in the higher RPMs.

Jake was running twins FULLY maxed out. They were blowing hot ass air. He even touches on this in his YT video and is one of the reasons he switched to a single turbo. He felt it would be more reliable with his new used engine and be able to make more HP. Which I agree. Twins on the ragged edge of the compressor map(which does not exist) or a single well within it's power range and compressor map.

The only people who hit high numbers on twins are the vendors. No one has come close to VTTs numbers for instance.

Excellent info. Didn’t realize that about twins but good to know and makes ST more attractive.

LOL at VTT. I may be saving for this speedtech then!

[Edris335i]

Originally Posted by pjr710

yea for sure .. i was googling today and i saw someone on another forum say they had a 300k ST n54 and was fine lol.

people were saying it comes down to the health of the motor (oil changes, etc)

but I def wanna know! also FWIW Jake Spence on YT has his 135 .. and he blew a motor that had 120k (not sure why) and replaced it with a 100k one I think. And I believe the 120k was pretty abused and might have blown for a reason other than just normal failure.

Iirc I remember that he was pushing a decent amount over 20psi of boost on the stock twins.

[teknic90]

Originally Posted by pjr710

yea for sure .. i was googling today and i saw someone on another forum say they had a 300k ST n54 and was fine lol.

people were saying it comes down to the health of the motor (oil changes, etc)

but I def wanna know! also FWIW Jake Spence on YT has his 135 .. and he blew a motor that had 120k (not sure why) and replaced it with a 100k one I think. And I believe the 120k was pretty abused and might have blown for a reason other than just normal failure.

Holy crap! 300k! That's insane!

OP, if you go ST I would be interested in hearing how the build goes. That speedtech kit looks VERY nice! I want to know how reliable and put together those kits are.