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Discussion Starter #1
I'm researching the idea of boosting the 2012+ Duratec engines and need more data. I know, I know, get an ST. I'm not. I want to boost mine.
For background, I'm a mechanic and an engineering student. I can plan it and build it, I just don't have the experience that this community does.

First, how much power have you all put through "stock" D20, D23, Zetec engines?
To be clear, by stock I mostly refer to the head and block. I would hope you replaced the intake and exhaust when boosting a naturally aspirated car...
How much horsepower and torque have been made without moving to forged internals? I need to know what exactly the breaking points are in the D20 specifically.

While I'm talking to the people who know this stuff, I want to address the compression ratio and my thoughts on it.
From 2011 to 2012 there were several changes, but here's why that's not an issue.
10.8:1 compression ratio in 2011
12:1 compression in 2012
Mathematically, 2012 had 11% more cylinder pressure at compression than 2011. 2011 had 90% the cylinder pressure of 2012. So whatever boost figure is safe for 2011, 90% of that would make nearly the same internal cylinder pressure inside the 2012. This means a 2011 engine running 10lbs with the FSWerks turbo kit, the 2012 would be running nearly the same internal cylinder pressure with 9lbs. Clearly compression won't be an issue there.
Now for pre-detonation, the other reason people don't put boost on high compression engines. The 2012 introduced direct injection, in which the gas is injected near the peak of the compression stroke, essentially eliminating the possibility of pre-det entirely. Not to mention the 2012 has oil squirters to keep the pistons cool, further reducing the already low pre-det chances. Also, it should be a given, but 93oct is all I have and will ever run in this car, so I'm sure that will help.

So pre-det is a non issue and over-boosting the internals shouldn't happen so long as already established safe boost levels are followed and Ford didn't make the engine weaker from 11 to 12.
Thoughts? Thanks in advance for any information.
 

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I'm not too sure on the mk2 or mk3 duratecs but I know that 12 psi is the "safe upper limit" for boost on a mk1 D23 or D20. Now, the power that comes from that boost depends on the turbo being used as well. I've seen forum members push 280 whp on a stock block with no issues but I wouldn't suggest doing that for a daily driver. The weak point for mk1 duratecs are the rods and pistons. Unless Ford went with an even weaker rod (to save money or whatever), I think you would be just fine with 9-10 psi with the right turbo; even with the higher compression. It really comes down to the tuning. Direct injection is also interesting; Idk too much about it except that the MZR guys haven't had any issues. I'm curious to see what focus tuners have to say about the matter.

I just finished my turbo build and I'm only running 7 psi but that's because I'm using a holset hx35 turbo. Big turbo, late spool. No peer pressure here but definitely do it haha boost is awesome
 

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I would have to manually check it for sure when I have more time, but I don't believe the math works in the way you're illustrating. Cylinder pressure increases exponentially with higher compression ratios, so that additional compression should correlate to similar cylinder pressures at a lower boost pressure-not just 90% of what a D20 would see.

Hopefully that makes sense when read. Basically, math could show similar cylinder pressures at max boost with 12:1 at 5 psi as it does 10.8:1 with 10 psi (random numbers, not correct). That's why OEM usually drops cr when boosting-it creates a less-drastic rise in pressure which is easier to deal with for fueling/ignition requirements and is safer overall in the long-run.
 

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You may want to go back and redo some of your thinking , you put boost on the MK3 even 3-4psi you will have detonation , just because the MK3 is direct injections does not eliminate the chance of detonation , there were some stock MK3 that first came out that had detonation

Your thinking on the compression is also a little off , and I feel if you cannot run a least 10-14 psi then adding a turbo kit isnt worth doing in my opinion

Tom
 

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He's not exactly wrong in what he's saying about detonation, just not acknowledging (aware?) the fact that it's a function of the tune. You can make any vehicle donate with a bad tune regardless of the presence of boost, but theoretically someone investing in boosting a Mk3 would also incest in a competent tuner as well.
 

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Discussion Starter #6
I realize tuning plays a huge role in this whole process, I think I just thought it to be a given when I typed that out. Not to mention starting at the lowest boost level possible and moving gradually up from there.
Like I said, I'm still fairly new to the performance world, but I really don't think this is unachievable.
With the compression ratio, I get what you're saying about the cylinder pressure being higher exponentially higher, I'm just thinking the difference can't be that much.
Something to back up my thoughts on the compression though,
These figures were all taken from the FSWerks website, for the sake of consistency.
I think it could be fair to say measured torque is directly related to how much pressure the engine can handle. First and second gen D20 has a baseline torque of about 120, baseline for the third gen is about 135. That's a little better than a 10% gain, reflective of the 11% increase in compression ratio. That may be coincidence, but the point is the FSWerks turbo kit increases the torque to 230. That's nearly double. I'm sure the cylinder pressure responsible for 230lbft of torque is rather high, significantly higher than the pressure responsible for 135lbft. Does that mean 230 is the reasonable maximum torque I should put through a third gen D20? If I stayed in the neighborhood of 200lbft or so, would it be reasonable to assume the cylinder pressure is less than if it were 230lbft?
I could be totally wrong here, all I have is these numbers, no real experience making it happen, but I've yet to see anyone address these facts with real math instead of intuition and guesses.
Thanks for your time discussing this with me, guys. I really want to figure this out.
 

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Hit up Tri-Point engineering.
 
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