1M to use twin turbo N54 - or so tell these pictures

[JB135MDCT]

Originally Posted by gxanthop

I wonder what are they gonna call it (engine)...It should start with an S.

S54.497706 4 cats, 2 turbos, N55 head, M1 SW and some "is" parts.

[MinusS50]

I will rather think they will take the complete fuel system from the N55 for sure (more rail pressure and for sure better injector) for the hybrid part.

After they may do some change on the exhaust system (like a two new manifold) and possibly some new turbocharger with the VNT system (same as Porsche).

And for sure the engine name will be branded with a S but for sure not a carry over of the performance pack (they still need to keep the M identity)

Just my 2 cents (of euros ...)

[sparoz]

Originally Posted by ///Mangler

So how are you going to handle the transients with one scroll getting twice the exhaust gas of the other that feed the same turbine?

T

Good point and I never thought about potential issues. Now you got me searching for answers, but I am sure the BMW engineers can work that out.

Originally Posted by madfast

that setup makes no sense. no matter how many scrolls you have, you still have only 1 turbine being fed by 3 cylinders. you cant evenly divide 3 into 2. unless you have some super trick valve that actively diverts gas into alternating scrolls, it cant be done... and even then it probably wont be worth it...

Apart from issues with transient operations as mentioned above, you don't need it to evenly distribute the cylinders as the point of the twin scroll is the separation of the charge pulse to reduce interference. The fact that the current setups involve an even split doesn't mean it is a requirement. Two drives from one scroll and one from another on the same turbine, with tuning of the length and size of the runners of the manifold would further optimise the back pressure even if it's not "paired" compare to a single twinscroll setting.

[sparoz]

Originally Posted by ///Mangler

So how are you going to handle the transients with one scroll getting twice the exhaust gas of the other that feed the same turbine?

T

Just did a quick search - it housing only have one waste gate. Anything beyond that it's too complex for my little brain . Someone else who have better technical knowledge than my limited knowledge can tell me why it won't work rather than just "it needs to be divided in pairs". .

[E82tt6]

Originally Posted by Evan135

I think the line about " but it is not a straightforward transplant" could also mean no "is" engine. If you put an "is" engine in the 1M it would be a direct transplant from an "is". If this is true it could be a further advanced N54 than the "is" engine.

BMW would scrap the project before they put out an inferior M product. They are trying to use this car as a way to introduce the M brand to a new audience and M knows they would hurt the M brand for these new buyers if the motor was not a M quality engine. I can see where development of the new M3 motor was not ready yet and M has done something special with the N54.

Very wishful thinking... but S65? Only 7kg/15lb weight gain. The issue then is that the car would be superior to the M3 in all regards other than seating space, but then again the Z4 M was superior to the M3 in all regards other than seating space.

I can't think of any other engine that would qualify as "hybrid" using the old-school definition.

His statement seems to suggest more than N54 with bigger snails.

Better N53 (DI version of N52)? I imagine they could milk 350hp out of that engine quite easily. It also weights nearly 80lbs less than the N54. They could realistically get more than 400hp out of it with a 8000 rpm redline.

[MinusS50]

Originally Posted by MinusS50

I will rather think they will take the complete fuel system from the N55 for sure (more rail pressure and for sure better injector) for the hybrid part.

After they may do some change on the exhaust system (like a two new manifold) and possibly some new turbocharger with the VNT system (same as Porsche).

And for sure the engine name will be branded with a S but for sure not a carry over of the performance pack (they still need to keep the M identity)

Just my 2 cents (of euros ...)

Just another guess maybe to fit aswell the N55 turbocharger (that will improve the weight of 20kg) and adding a CCManifold (a la S63). I'm still keeping my idea for the fuel system

[Alext]

Well let's assume BMW do use the N54.

What i think is that BMW are unlikely to make it much faster than the current M3.

What do we know about BMW N54 tunes currently?

There is the standard 300HP tune, the 335is 320HP tune and...well this would limit them to around 340HP/250kw as per Z4 35is N54 level of tune which is as fast as a manual M3 already. Considering the M1 will be lighter but with a manual instead of the slighter quicker DCT, it puts it in about the ballpark. They may even take it to around 350HP but I don't see them going much more than that as they have to maintain model distinction.

I think it would be simple and efficient for BMW to implement this. A car that does 0-60 in around 4.7 sec, great handling, 2 door, relatively lightweight. Easy. 1M problem solved.

[bryce]

Originally Posted by sparoz

Just did a quick search - it housing only have one waste gate. Anything beyond that it's too complex for my little brain . Someone else who have better technical knowledge than my limited knowledge can tell me why it won't work rather than just "it needs to be divided in pairs". .

you cannot have a dual twin scroll manifold on a 6 cylinder engine, period. you'll get eratic boost response if one scroll has 2 cylinders feeding it and the other only has 1. think about that for a minute.

furthermore, a twin scroll turbo is designed to be more efficient than a traditional turbo. if you're getting eratic boost response from uneven cylinder pairing, how is that more efficient? it's not.

i don't really know why some mis-informed members on this website are hoping for a dual twin scroll setup. it's ricer talk and reminds me of people wanting "titanium valve springs" after the fast and furious came out.

[Xaeryan]

Originally Posted by bryce

i don't really know why some mis-informed members on this website are hoping for a dual twin scroll setup. it's ricer talk and reminds me of people wanting "titanium valve springs" after the fast and furious came out.

2F2F Yo! ;-)

My $.02 based on Scott's "hybrid" remarks are that this will be the well-established N54 engine with an N55 turbo setup (i.e. a single twin-scroll turbo) modified to suit an M car's required characteristics. Date it. I'll be back to collect my prize if I win. ;-)

[southlight]

Originally Posted by bryce

i don't really know why some mis-informed members on this website are hoping for a dual twin scroll setup. it's ricer talk and reminds me of people wanting "titanium valve springs" after the fast and furious came out.

Your point is well taken, the way you present it not so much. Having a master degree in mechanical engineering isn't a prerequisite for posting here, so please cut 'us' a slack.

Originally Posted by Xaeryan

My $.02 based on Scott's "hybrid" remarks are that this will be the well-established N54 engine with an N55 turbo setup (i.e. a single twin-scroll turbo) modified to suit an M car's required characteristics. Date it. I'll be back to collect my prize if I win. ;-)

I think the presence of mid cats rules out a N55 turbo setup.


Best regards,
south

[bryce]

Originally Posted by southlight

Your point is well taken, the way you present it not so much. Having a master degree in mechanical engineering isn't a prerequisite for posting here, so please cut 'us' a slack.


I think the presence of mid cats rules out a N55 turbo setup.


Best regards,
south

i don't have a degree in engineering, it's just simple forced induction concepts. this isn't my first turbocharged vehicle, unlike many members here. i've tried explaining how dual twin scroll setups are impossible on an inline 6 engine for a few weeks, when they start arguing about it and saying it is too possible, patience runs thin.

in regards to mid cats signifying twin or single turbo's, i don't think that's accurate or based on facts. yes, the n54 uses mid cats and the n55 doesn't, but that doesn't mean bmw will only use mid cat's on a twin turbo. perhaps there's a better downpipe/primary cat in place (when compared with the n55) so bmw deemed secondary cat's necessary. it makes sense for the m division to use a more efficient downpipe design than the n55, if the 1 series m coupe is in fact an n54 w/ a single turbo.

Originally Posted by Xaeryan

2F2F Yo! ;-)

My $.02 based on Scott's "hybrid" remarks are that this will be the well-established N54 engine with an N55 turbo setup (i.e. a single twin-scroll turbo) modified to suit an M car's required characteristics. Date it. I'll be back to collect my prize if I win. ;-)

i agree, and i've said the same thing here a week ago in the sticky thread

[southlight]

Originally Posted by bryce

in regards to mid cats signifying twin or single turbo's, i don't think that's accurate or based on facts. yes, the n54 uses mid cats and the n55 doesn't, but that doesn't mean bmw will only use mid cat's on a twin turbo. perhaps there's a better downpipe/primary cat in place (when compared with the n55) so bmw deemed secondary cat's necessary. it makes sense for the m division to use a more efficient downpipe design than the n55, if the 1 series m coupe is in fact an n54 w/ a single turbo.

I think it's the other way round. If possible, they'd want to lower the back pressure by getting rid of the mid cats. That's the way Alpina went with the (N54) B3 S.


Best regards,
south

[crzy4135i]

Originally Posted by bryce

i don't have a degree in engineering, it's just simple forced induction concepts. this isn't my first turbocharged vehicle, unlike many members here. i've tried explaining how dual twin scroll setups are impossible on an inline 6 engine for a few weeks, when they start arguing about it and saying it is too possible, patience runs thin.

in regards to mid cats signifying twin or single turbo's, i don't think that's accurate or based on facts. yes, the n54 uses mid cats and the n55 doesn't, but that doesn't mean bmw will only use mid cat's on a twin turbo. perhaps there's a better downpipe/primary cat in place (when compared with the n55) so bmw deemed secondary cat's necessary. it makes sense for the m division to use a more efficient downpipe design than the n55, if the 1 series m coupe is in fact an n54 w/ a single turbo.



i agree, and i've said the same thing here a week ago in the sticky thread

Haha.. I do have a degree in engineering but the only detail I care about is they do whatever it takes to provide 370+hp and good torque from idle.

[sparoz]

Originally Posted by bryce

you cannot have a dual twin scroll manifold on a 6 cylinder engine, period. you'll get eratic boost response if one scroll has 2 cylinders feeding it and the other only has 1. think about that for a minute.

furthermore, a twin scroll turbo is designed to be more efficient than a traditional turbo. if you're getting eratic boost response from uneven cylinder pairing, how is that more efficient? it's not.

Why would it give an eratic boost if it's timed correctly? I admit my ignorance, but I cannot see why you need a even split still. Call me dumb, but I don't think anyone had really explained why. Or you can point to the threads that you have a more detailed explaination.

Your second argument is based on your first premise so... really the critical part is why it will have eratic boost. May be someone else can chip in so we can kill this topic once and for all.

[crzy4135i]

Originally Posted by sparoz

Why would it give an eratic boost if it's timed correctly? I admit my ignorance, but I cannot see why you need a even split still. Call me dumb, but I don't think anyone had really explained why. Or you can point to the threads that you have a more detailed explaination.

Your second argument is based on your first premise so... really the critical part is why it will have eratic boost. May be someone else can chip in so we can kill this topic once and for all.

You guys have me confused. I thought "twin scroll" was the turbine housing having a divider wall in it. Doesn't the housing still only have one inlet connection, so exhaust piping from the three cylinders would merge together before the turbo? After the merge, the combined gas enters the turbo as one exhaust stream?

[///Mangler]

Originally Posted by crzy4135i

You guys have me confused. I thought "twin scroll" was the turbine housing having a divider wall in it. Doesn't the housing still only have one inlet connection, so exhaust piping from the three cylinders would merge together before the turbo? After the merge, the combined gas enters the turbo as one exhaust stream?

[Source- "Maximum Boost" by Corky Bell]

Twin scroll turbine housing. The TST housing derives its name from the geometry of the exhaust gas inlet into the turbine. Two different-sized scrolls are generally used, a primary and a secondary. Typically, the primary is open for low-speed operation, and both for high-speed use. This creates the ability of the TST to be a small A/R housing at low speeds and a large A/R at higher speeds.
TST designs are of merit in that they offer a better combination of low-speed response and high-end power. It would be difficult to configure the unit to control boost by effectively varying A/R. A wastegate is therefore still necessary to control boost pressure. Simplicity of the twin scroll turbine housing is its big selling point.

in my opinion ,predoinantly twin scroll housing is used n diesel turbocharging systems on the engines having more than 4 cylinders to reduce pulsasation of these engines .
Additonaly , output of some cyliders will go one scroll and remaining in other to cut down pulsastations

[madfast]

Originally Posted by sparoz

Why would it give an eratic boost if it's timed correctly? I admit my ignorance, but I cannot see why you need a even split still. Call me dumb, but I don't think anyone had really explained why. Or you can point to the threads that you have a more detailed explaination.

Your second argument is based on your first premise so... really the critical part is why it will have eratic boost. May be someone else can chip in so we can kill this topic once and for all.

well first of all, you have 3 exhaust gas pulses that ultimately get divided between 2 scrolls. how on earth can you alternate them such that they dont "run into each other"? you will have to eventually have one scroll being fed by 2 pulses consecutively. the math just doesnt work

ok so we "time" these pulses right? "time"? how do you "time" it without slowing down the exhaust gas velocity which is vital to spool? custom tubular manifolds have LAG for this very reason. at high rpm its great due to better flow but its lower velocity hurts spool.

im no engineer, but the simple fact that you cant divide 3 into 2 is very important. you will have to design a very complicated system that in the end probably wont be worth the trouble...

[Evan135]

The terminology causes the problems with everyones ideas. You can have a "twin Scroll" on an inline 6 and it should work quiet well. I have explained one way twice and read the threads and PM me with questions. I do not think they will do that though. It could be like some of their deisel projects where they use a small turbo(even it could be a twin scroll) in 3 cylinders and a larger(it could be a larger twin scroll too on the other 3. Before you say it will be imbalaced it can have a passover connection to equalise the pressure. I wish I knew how to put a sketch to these ideas so we could all see this.

There are at least 2 ways to skin a twin turbo, twin scroll design on an inline 6 that I know of if they want to do it. I am sure M can come up with even more. Most might be complicated and/or expensive so I am doubtful we will get one. My best hope is they apply the intake system off of the next M3 that is intended for the N55 but use it on a N54.

[///Mangler]

Why not the tri-turbo design from the new diesel? Oh, and this could be your "hybrid" that Scott mentioned.......

T

[southlight]

Some have presented quite good ideas...for the coming M3 engine.

As to the 1M, I still don't expect any significant changes to its engine. It will be an N54, maybe with a different oil cooler or different pistons, but the bi-turbo layout is there to stay.


Best regards,
south

[sparoz]

Originally Posted by madfast

well first of all, you have 3 exhaust gas pulses that ultimately get divided between 2 scrolls. how on earth can you alternate them such that they dont "run into each other"? you will have to eventually have one scroll being fed by 2 pulses consecutively. the math just doesnt work

ok so we "time" these pulses right? "time"? how do you "time" it without slowing down the exhaust gas velocity which is vital to spool? custom tubular manifolds have LAG for this very reason. at high rpm its great due to better flow but its lower velocity hurts spool.

im no engineer, but the simple fact that you cant divide 3 into 2 is very important. you will have to design a very complicated system that in the end probably wont be worth the trouble...

Imagine you are spinning the spool with your left hand and right hand. You do it once with your left and twice with your right - it works (I know it is over simplistic).

The way I see it is that having two pulse on one scroll is definitely better that three on one scroll. If you look at firing sequence 1 2 3 4 5 6 (not cylinders), where Turbo A connects to 1 3 5 and Turbo B connects to 2 4 6; Scroll A1 connects to 1, 5, and A2 connects to 3, Scroll B1 connects to 2, 6 and B2 connects to 4. The volume and pulses feed to the charger is the same - 3 by volume of air, and they would be evenly spaced out regardless of the uneven scrolls as the two scrolls feeds to one charger. The continuous feeding of the charger should create the back pressure require on the two scrolls, while the separation of the two cylinders on one scroll and the isolation of the one cylinder on the other should reduce interference. Timing, as far as I know is done by the size and length of the runners in the manifold - CCM is the latest BMW technology. As the key to this set up is in the manifold, I believe BMW, who is renowned for this would be able to come up with a solution.

I am no engineer but that's why I can't see why it is a problem, and of course due to my limited knowledge and understanding. However, I think I am guilty of getting this OT. Let's go back to the N54.

Originally Posted by Evan135

There are at least 2 ways to skin a twin turbo, twin scroll design on an inline 6 that I know of if they want to do it. I am sure M can come up with even more. Most might be complicated and/or expensive so I am doubtful we will get one. My best hope is they apply the intake system off of the next M3 that is intended for the N55 but use it on a N54.

+1 - I would be happy with that if it delivers better response from the engine. The Cylinder-bank Comprehensive Manifold so they called it seems to be the key to the S63.

[Future M1 owner]

Originally Posted by Alext

Well let's assume BMW do use the N54.
There is the standard 300HP tune, the 335is 320HP tune and...well this would limit them to around 340HP/250kw as per Z4 35is N54 level of tune which is as fast as a manual M3 already. A car that does 0-60 in around 4.7 sec, great handling, 2 door, relatively lightweight. Easy. 1M problem solved.

Which amounts to the admission that M-Division engine gurus and magicians were kindly asked to sit this one out......