VTT GC's 847WHP/726WTQ

[Velocity26]

I pulled up a log and can see where Fuel pressure requested is right at 3,000 psi during a pull. That is with Cobb stage 2. Pretty sure that going to 4,000 would only be a 33% increase. Not sure how much Cobb has messed with the fuel pressure tables, but I doubt they did much considering that this tune was developed years ago and this was not even a topic then.

[Traf]

Well in that case, stock boost is 7 psi, 14 psi CAN'T be good. You know its almost double the stock boost levels. Your logic of it being twice factory levels, makes little sense. Who's talking Diesels here? Yes they run as much 15K psi at time in the cummins. Were talking GDI motors, 3600 psi not high, but like I said, let people think it is. Its fine with me...

Thats really not the same thing, and even if it was, you have to have supportive mods to safely run twice the boost right ? Like CP upgrades because the stock ones tend to explode, fmic and dp's...
On the other hand our fuel system is already well known for being really unreliable, and you just stress it even more. Aren't your afraid of injector failures or leaks ?
But whatever i'll be the first to buy a barrel from you once we get good independent results.

I pulled up a log and can see where Fuel pressure requested is right at 3,000 psi during a pull. That is with Cobb stage 2. Pretty sure that going to 4,000 would only be a 33% increase. Not sure how much Cobb has messed with the fuel pressure tables, but I doubt they did much considering that this tune was developed years ago and this was not even a topic then.

Well that's high, but i'd prefer it a little bit to high than too low. My flash is targeting very very low high pressure, don't know why.

[Tony@VargasTurboTech]

I pulled up a log and can see where Fuel pressure requested is right at 3,000 psi during a pull. That is with Cobb stage 2. Pretty sure that going to 4,000 would only be a 33% increase. Not sure how much Cobb has messed with the fuel pressure tables, but I doubt they did much considering that this tune was developed years ago and this was not even a topic then.

Ssssshhhh. Let him think 3600 is much too high of rail pressure to run. He is right, its WAY too high, no one should ever run over factory rail pressure levels.

[Traf]

Ssssshhhh. Let him think 3600 is much too high of rail pressure to run. He is right, its WAY to high, no one should ever run over factory rail pressure levels.

Lol you're a child dude it's like impossible to have a real discussion with you.

[j_hynson]

From what I've seen, they come REALLY rough with a ridiculous amount of meat left to remove. Even the "stage 3" seems conservatively modified.

VAC just recently redid the program for their stage 3 head. I had the old program and now I have the new program machoned Big difference

[AWSAWS]

How much power did you make with your GC's?

I pick my car up this morning after a full motor rebuild, forged bottom etc and can't want to see what the GC's do after run in.

I've not really gone too mad yet. According to virtual dyno I'm on about 530whp at 22 psi. I'm not wanting to go too much higher on the stock DCT clutches for now.

Just recently I've been getting the M3 control arms put on and had to replace the siezed tie rods so the car hasn't been drivable for a few weeks. Before that I had issues with a sticky caliper meaning even normal driving was cooking my rear right brake. I've replaced that as well.

[AWSAWS]

Lol you're a child dude it's like impossible to have a real discussion with you.

In cases like this Tony just needs to point out that he's run higher than stock figures and seen no adverse effects rather than coming across as so aggressive and confrontational.

Forum chat is devoid of body language, intonation etc. It's very easy to be perceived as being a dick when you don't mean to be.

[Tony@VargasTurboTech]

In cases like this Tony just needs to point out that he's run higher than stock figures and seen no adverse effects rather than coming across as so aggressive and confrontational.

Forum chat is devoid of body language, intonation etc. It's very easy to be perceived as being a dick when you don't mean to be.

I am not being a dick at all. People are entitled to their own opinion. Like I said, honestly let people think running these pressures is detrimental. Those people will continue to struggle to extract consistent big power from these motors. I am not here to convince anyone to run 3600+psi rail pressure. Even with the shotgun you can still set your pressure in the flash. Run it at 1800psi if it makes you feel more comfortable.

[Velocity26]

Tony,

What are "Stock" rail pressures?

I assumed that mine were "stock" since there was no need to do anything to support the power levels that my tune makes. I know that I have seen targets and pressures of 3,000 psi on my logs, but am too lazy to flash back to stock just to run a log and see what the BMW targets are.

[Tony@VargasTurboTech]

These are the stock HPFP targets.

[shushikiary]

Note that's in mega pascals, so 17 is about 2500 psi.

I remember when we were looking at the data sheet on the stock injectors they had a chart that showed they were tested all the way up to 4500 PSI I thought, though I dont remember seeing a "max pressure" rating.

Knowing BMW, and how dangerous those pressures are if they leak (think water jet cutting), I wouldnt at all be surprised if the stock HPFP rail and injectors were designed to have a peak pressure rating 2-5 times the max the HPFP can put out. Also given how long MANY aftermarket tunes have pushed 3600 PSI at mid range RPM high boost (like 3-3.5k RPM) and we havent seen any failures, I'm confident its fine.

[Traf]

Note that's in mega pascals, so 17 is about 2500 psi.

I remember when we were looking at the data sheet on the stock injectors they had a chart that showed they were tested all the way up to 4500 PSI I thought, though I dont remember seeing a "max pressure" rating.

Knowing BMW, and how dangerous those pressures are if they leak (think water jet cutting), I wouldnt at all be surprised if the stock HPFP rail and injectors were designed to have a peak pressure rating 2-5 times the max the HPFP can put out. Also given how long MANY aftermarket tunes have pushed 3600 PSI at mid range RPM high boost (like 3-3.5k RPM) and we havent seen any failures, I'm confident its fine.

Thats what i'm talking about! Thanks for the info.
Why isn't this coming from Tony himself is another story.

[Tony@VargasTurboTech]

Thats what i'm talking about! Thanks for the info.
Why isn't this coming from Tony himself is another story.

Why this is not coming from me? Can you please show me one place where I recommend people run 3600PSI. I will say it again for reading comprehension sake. EVEN running a shotgun, you set your OWN pressures in the flash tables, run whatever you want. The shotgun does NOT raise the pressure capability of a single component on the N54 engine. It simply allows you to flow more fuel supply to meet demand. We are not tuners, nor do we consult on tuning. Rail pressure is set in the tune, so again why would tuning info come from a hardware manufacture? Also the paper he is talking about, is readily available for anyone who wants to read it.

[Sticky]

VAC just recently redid the program for their stage 3 head. I had the old program and now I have the new program machoned Big difference

Do they have the flow charts for both?

[j_hynson]

Do they have the flow charts for both?

Idk but i can tell the difference just by looking at it. Seems like they took a lot more meat on this program

[Sticky]

Idk but i can tell the difference just by looking at it. Seems like they took a lot more meat on this program

Would you mind posting pics? A new thread on this would be greatly helpful.

[j_hynson]

Would you mind posting pics? A new thread on this would be greatly helpful.

Ugh I thought about doing that.

When I swap in studs for intake manifold I'll pull it and take pictures. I have pictures of the old VAC head program in my build thread but the old VAC head I had hand smoothed so don't know exactly how much justice comparing the two will do

[Sticky]

Ugh I thought about doing that.

When I swap in studs for intake manifold I'll pull it and take pictures. I have pictures of the old VAC head program in my build thread but the old VAC head I had hand smoothed so don't know exactly how much justice comparing the two will do

So no pics of the new ones right now?

[j_hynson]

So no pics of the new ones right now?

Soon. Going to bigger injectors so when I pull that I'll take tjem

[Ericbh77]

My head is being refinished as we speak. Should have some pics for you in a few days. The block looks great tho.

[Sticky]

My head is being refinished as we speak. Should have some pics for you in a few days. The block looks great tho.

VAC head as well?

[Ericbh77]

Of course. And custom block work too.

[Sticky]

Of course. And custom block work too.

Oooohhh that's pretty.

[maxnix]

Of course. And custom block work too.

Dayum! I wonder if that cools a little better?

One thing BMW realized when they did the N55 update is that the N54 cooling passages in the head could have been larger. This might mitigate that N54 design shortcoming which has to be exacerbated by most closed deck solutions for the N54 seen to date.