Thanks for the tip! I will be using a ReFlex for port injection, will look at using it to provide the PWM signal.
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Custom Big Single Turbo To Custom Twin (S55) Turbo upgrade
- Thread starter Dumaurier7
- Start date
To be honest, I think the best route for you here would be to pick up an S55 DME out of a wrecked one (MEVD 17.2.G) and have someone like Levan @ BimECU clone your vehicle's ISN to it.
ReFlex can provide a PWM signal indeed, but it will not be able to provide one to match the boost curve that the DME is commanding / controlling for the other bank.
Additionally, you will have a big fueling issue, as the closed loop lambda feedback will only be from 3 cyl. Even if you merge both downpipes in as short of a distance as possible, it will still be a bit far for accurate control.
I would get the S55 DME, clone your ISN, and then have your tuner code out / disable the S55 related things you aren't using (2nd hpfp, w2a items, etc)
ReFlex can provide a PWM signal indeed, but it will not be able to provide one to match the boost curve that the DME is commanding / controlling for the other bank.
Additionally, you will have a big fueling issue, as the closed loop lambda feedback will only be from 3 cyl. Even if you merge both downpipes in as short of a distance as possible, it will still be a bit far for accurate control.
I would get the S55 DME, clone your ISN, and then have your tuner code out / disable the S55 related things you aren't using (2nd hpfp, w2a items, etc)
Great tip and advice once again! In the past I had bent the ignition output pin for cylinder #5 which caused some headache as expected, I eventually found it and straightened it back out, but it felt kinda flimsy like it was about to break so I always intended to just change the DME instead of opening it up and replacing the pin. This rebuild will give me the opportunity to kill more than one birds with one stone! thanks! Only question though would be the engine harnesses and the electric water pump?!
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Soooo, @Bimecu said he/they cannot help 
, any other suggestions? I am sure there is someone out there who can assist but if this solution proves to be impossible, the only other solution I can think of is to use two of the controllers! In that configuration the DME will talk to the Reflex and the reflex will talk to each controller.
, any other suggestions? I am sure there is someone out there who can assist but if this solution proves to be impossible, the only other solution I can think of is to use two of the controllers! In that configuration the DME will talk to the Reflex and the reflex will talk to each controller.
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I just spoke with Levan, he replied no to your email because you were requiring too much on his end. I had said they would clone the ISN from your DME to the S55 DME. That is all BimECU will handle.Soooo, @Bimecu said he/they cannot help
The rest of the process (coding out / turning off 2nd hpfp, W2A items, etc) needs to be done by your tuner, so make sure you are working with one that also knows what they are doing.
If the ReFlex is mirroring exactly what the DME is doing why wouldn't it be able to match the boost curve? can you explain
I already considered this; I may have to switch tuning platforms (SORRY!) as you guys don't allow for additional inputs to the DME yet.
ReFlex: mirroring will likely not work (even though ReFlex receives final WGDC over CAN from the DME, and then can output it on Aux1 as square wave PWM).... because.... that WGDC is derived from the DME internal electronic waste gate control model, through many tables. There is absolutely no way that will match what the DCCDPro controller is doing for converting PWM Duty Cycle to Electronic gate control.
For example, its usage range is 5-95% PWM DC input. The DME (calculating things the other way....wgdc -> gate position control) uses 0 to 100%.
And for switching platforms... sorry to disappoint but there is no other platform that will give you closed loop lambda control on the bank 2 cylinders, separately from the bank 1 cylinders, on a single bank (N55) DME. I don't care how many extra I/O they offer. I'm assuming you're talking about EcuTek here. They don't even have S55 / S58 single bank figured out yet. We (MHD) do.
No offense, but you are clearly out of your depth here on getting this project to actually work. I've told you what I would do to guarantee it work. You can take my advise or not, up to you
Thank you for sharing!
Jake@MHD
And for switching platforms... sorry to disappoint but there is no other platform that will give you closed loop lambda control on the bank 2 cylinders, separately from the bank 1 cylinders, on a single bank (N55) DME. I don't care how many extra I/O they offer. I'm assuming you're talking about EcuTek here. They don't even have S55 / S58 single bank figured out yet. We (MHD) do.
Thanks again for sharing, the average layman like me will not know these things, thats part of the reason why I am here, to learn new things.
None taken by me, and yes, I am no way in "my depth" when it comes to knowing the possibilities with these cars and knowing what may or may not be possible with coding. I did take your advice; this is why I can report that the person you recommended declined to help.
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Like I said earlier, he declined because you asked him to also perform all the duties that your tuner would need to do. BimECU would clone ISN only.
...... Again, I cannot and would not know this, I don't do this sort of thing every day, he could have simply told me what you just did. So are you saying that that my tuner will (should be able to!) take care of everything else thats required? your assistance is greatly appreciated.
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New block arrived from Germany at my friends house couple days ago, next it's off to CSS!
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looks like at this point, this is more or less trying to make an N55 into the S55. If you need to use an S55 DME, why not just get an actual S55? pretty sure it will be cheaper than doing all the machine work to the N55 plus hardware upgrades necessary to take full advantage of these 2 turbos. And you won't have to disable second hpfp, which is probably good. Your manifolds probably should bolt up to S55, shouldn't they?
Thanks for your response, what I’m doing is in no way trying to make my N55 into an S55! But with that mode of thinking I can understand why the N55 platform never saw its true potential.
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Jake@MHD I think you’ll be pleased to know that i DID take your advise and have since secured an S55 main engine harness and DME!
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Been thinking about how the engine water pump could or would b controlled, one possibility is to hijack the control signal to the turbo auxiliary water pump, is anyone aware of the control scheme for this pump?
The block got to CSS successfully, they then informed me that they will not touch the block unless it's being honed after the closed deck modification so I would need oversized (84.5mm) pistons. I immediately checked the slugs I bought before 'cause I know I bought standard sized ones (84mm) as I did not know honing would be necessary with a new block.........only to see this!!!
Honing to 84.5mm is always necessary after every Closed Deck Conversion. During installation under pressure you are changing the cylindricity of the cylinder. To get it in working shape again, you go half a mill bigger or whatever is available for the specific engine. On N54 84 --> 84.5
Not sure if you can resleeve the block after Closed Deck Conversion. But this may be another option to stay with the OEM bore.
Not sure if you can resleeve the block after Closed Deck Conversion. But this may be another option to stay with the OEM bore.
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This is an essential fact that CSS failed to mention on their web site, luckily the vendor is exchanging the pistons so I'll get the oversized (84.5mm) ones required.
