ec17pse said:

your 14B in these comment dont belong here

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ec17pse said:

the 14B fuek setup on a 1G is more aggressive then a 2G ecu

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Disagree, and stay mad I guess.

Stapl3 said:

Disagree, and stay mad I guess.

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Im not mad i dont get why you mentioned a 14B when the OP came from a T25, i know where your coming from but its an invalid point as the 1G ecu is different then a 2G ecu fuel map wise, a 14B in a 2G will be better suited as it dont have as much top end a 16G does even being a small 16G.

ec17pse said:

i know where your coming from but its an invalid point as the 1G ecu is different then a 2G ecu fuel map wise

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It's like I'm making invincible posts to a person that's never attempted to calibrate a ecu.

The target a/f ratio of the 1g and 2g ecu has zero affect on a stock setup successfully pulling off a stock turbo at wg boost pressure.

Op is asking about 12psi. 12psi.

Stapl3 said:

It's like I'm making invincible posts to a person that's never attempted to calibrate a ecu.

The target a/f ratio of the 1g and 2g ecu has zero affect on a stock setup successfully pulling off a stock turbo at wg boost pressure.

Op is asking about 12psi. 12psi.

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Listen or read, the OP dont have this abikity to do so yet so your replys are invalid again, read what the OP has and dont have and reoly back with helpful replys that he CAN actually do! This is not about me and i know what to do but the OP is the one needing help NOT me,

So forget about the 14B and concentrate on his small 16G with stock ecu and stock fuel etc etc, keep it simple for others to follow aswel, i did my part is saying its fine for now and works ok and safe as a daily use car

Damn you guys really got into it, nonetheless thanks all for the info!! From all the info, i see that a 16g will be fine with a stock fuel system(evo9 pump soon), injectors when i can get a tune. I guess ill find out when i finish the install whether ill have problems or not. To give you guys a bit more input, my current setup is basically a close to stock 2g.
-aftermarket bov
-downpipe no cat, 3inch exhaust straight pipe till muffler.
-tube header
-injen intake

Also, out if topic. But i hear 2gs bug out when running atmo bovs? Running rich and stalling out and such. Mine doesnt seem to do any of that and my bov is atmo

ec17pse said:

Listen or read, the OP dont have this abikity to do so yet so your replys are invalid again, read what the OP has and dont have and reoly back with helpful replys that he CAN actually do!

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ec17pse said:

its an invalid point as the 1G ecu is different then a 2G ecu fuel map wise

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They both target mid 9's afratio stock, so I don't even know why you brought it up yet again. Even if they were different as you suggest, it wouldn't matter.

12psi on a t25, 14b, 16g is all the same thing. Run either one you want on a bone stock car, at 12psi if there's an issue, it's not the turbo.

Stapl3 said:

They both target mid 9's afratio stock, so I don't even know why you brought it up yet again. Even if they were different as you suggest, it wouldn't matter.

12psi on a t25, 14b, 16g is all the same thing. Run either one you want on a bone stock car, at 12psi if there's an issue, it's not the turbo.

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as stated above 12 psi is not 12 psi on all turbos, well it is but its not. it gets confusing here, 12psi with one turbos means it flows X amount of air, 12 psi on another turbos flows a different X amount of air causing its to act differently and need different fueling requirments, while ll can be used on a stock 2G ecu they react differently, the 14b might not fuel cut were a 16g likely will, its been proven many times here that its an issue so please go search it if you dont believe me

Amazing.

Stapl3 said:

Amazing.

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what ever. Have a nice day

I think the bigger thing to take into account here, when comparing the T25 to a 16G, is the fact that at the time the T25 peaks maximum airflow (per given psi), the 16G will go even further. On mine the T25 really stops doing anything at and past 5000 RPM. It's just hot air at that point. The 16G should technically keep providing the target 12 psi at and above 5000 RPM, like ec17pse said. Then the problem becomes whether the stock 2G fuel map has enough leeway to safely add more fuel to keep the AFR stable at and above 5000 RPM at 12 psi pressure.

That said, running the 16G with everything else stock (even sidemount) should still increase engine power slightly even if both turbos are ran at 12 psi. Again, if the T25 peaks at 5k @ 210 HP, the 16G should make slightly more peak power at 5500-6000 RPM, I'd guess anywhere between 250-260 HP. At least that's what I've seen. But of course, add a proper cooler, exhaust, some porting and polishing and you'll easily break 300 at the crank. From then on it's how good of a tune you can get and how much you're willing to crank up the boost (to the moon I say !)

Kryndon said:

I think the bigger thing to take into account here, when comparing the T25 to a 16G, is the fact that at the time the T25 peaks maximum airflow (per given psi), the 16G will go even further. On mine the T25 really stops doing anything at and past 5000 RPM. It's just hot air at that point. The 16G should technically keep providing the target 12 psi at and above 5000 RPM, like ec17pse said. Then the problem becomes whether the stock 2G fuel map has enough leeway to safely add more fuel to keep the AFR stable at and above 5000 RPM at 12 psi pressure.

That said, running the 16G with everything else stock (even sidemount) should still increase engine power slightly even if both turbos are ran at 12 psi. Again, if the T25 peaks at 5k @ 210 HP, the 16G should make slightly more peak power at 5500-6000 RPM, I'd guess anywhere between 250-260 HP. At least that's what I've seen. But of course, add a proper cooler, exhaust, some porting and polishing and you'll easily break 300 at the crank. From then on it's how good of a tune you can get and how much you're willing to crank up the boost (to the moon I say !)

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to the moon! i got to put into consideration that the car has 150k miles but still has good compression. max boost ill probably, when i get the evo 9 fuel pump is 15 to play it safe

Kryndon said:

Then the problem becomes whether the stock 2G fuel map has enough leeway to safely add more fuel to keep the AFR stable at and above 5000 RPM at 12 psi pressure.

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The stock 'map' has absolutely nothing to do with getting enough fuel.

These are the 1g and 2g target afratio tables. As you can see, they are nice and fat in the mid 9's while at max tilt. You could run a 42r at 60psi on these and it would be fine. Aside of leaning it out to the desired target while at max boost, these aren't really even messed with that much.

Allen2g said:

Damn you guys really got into it, nonetheless thanks all for the info!! From all the info, i see that a 16g will be fine with a stock fuel system(evo9 pump soon), injectors when i can get a tune. I guess ill find out when i finish the install whether ill have problems or not. To give you guys a bit more input, my current setup is basically a close to stock 2g.
-aftermarket bov
-downpipe no cat, 3inch exhaust straight pipe till muffler.
-tube header
-injen intake

Also, out if topic. But i hear 2gs bug out when running atmo bovs? Running rich and stalling out and such. Mine doesnt seem to do any of that and my bov is atmo

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The evo 9 pump or even a walbro 190 should do a great job on your Dsm without having to mess with the air fuel pressure regulator. That small 16g and some slightly larger low resistance injectors can get you what your looking for out of the car. That's awesome you can vent your bov on a maf without any issues! Fortunately I was able to do the same back when I was near stock with no problems but now I'm on speed density. You may want to consider looking for ecmlink or a flash depending on how large of injectors you go. Just don't waste money on a cheap alternative they never work correctly!

my understanding fuel cut has nothing to do with AFR, it is based on how much air the maf is reading. If airflow passes the factory programmed safe level it cuts fuel. When at WOT the ecu does not monitor AFR and relays on the maf to tell it how much air is coming in and uses a X amount of fuel for X amount of air. Reading through this thread there is a lot of talk about about AFR that's seems inaccurate for the topic of fuel cut. As for running 12psi from turbo A vs turbo B, the Psi is the same but the CFM is different. A bigger turbo at the same boost level will run cooler then a smaller turbo resulting in more efficiently compressing air. Colder the air the more dense it is. As for the OP, yes you can run a 16g at 12 psi on the factory fuel system, this is not enough airflow to over flow the factory safe zone. But it will be a little bit slower then what your used to and your not going to have much room to grow until the fuel system and tuning solution is addressed. If your hitting fuel cut at 12 psi you need to look into finding a possible boost leak that is misleading the MAF to think more air is going into the engine then what really is, boost leaks make the turbo work harder to accomplish the same task. The MAF doesn't know how much air the engine is getting just what the turbo is pulling.

The MAF is what the ecm uses to determine how much air will be entering the engine unless you are running SD.
Atmospheric pressure is what pushes air through the MAF then to the turbo where it is compressed, the compressed air eventually makes it to the engine cylinder after making a density recovery stop at the intercooler.
With a properly calibrated MAF the ecm will calculate the proper amount of fuel needed for stoich during closed loop with the help of O2 sensor and fuel trims, in open loop it will use MAF feedback and reference the fuel map with no O2 reference.
It doesn't matter which turbo you have on the car if you exceed the preset MAF limit fuel cut will be triggered whether it be 10 to 100 psi. Increase the VE of the engine with something like cams and you will probably be hitting fuel at lower boost pressure because of increase air through the MAF.
The easy trick if you hit fuel cut is to back the screw in the bottom of the MAF sensor to allow uncounted air to bypass in the MAF thereby reducing the amount of air the ecm thinks will be entering the engine.
There are plenty of options to delay fuel cut, bigger injectors and SAFC works well for cheap. It doesn't change the actual fuel cut limit but it allows you to reduce the reported airflow seen by the ecm which effectively increases the fuel cut limit.

On a side not, I'm not 100% positive if the fuel cut limit is determined by just a karman limit or a combination of karman & AFR map. So running say 1600hz at 12.0 may not hit fuel cut while 1600hz at 9.6 might hit fuel cut.

Will i need to port my o2 housing? Also, to run on wastegate pressure, i just connect the nipple from the wg to the nipple on the jpipe? <till my mbc arrives

You don't need to port your o2 housing unless you just want to really, there are limitations to how much you can port it.
But if you have it off and have the energy to burn why not, it shouldn't hurt anything.
Yes you just connect the wastegate to where ever you want to boost reference to be coming from.
Pressure at the j-pipe can be higher than at the intake manifold depending on how restrictive the intercooler an plumbing is. This doesn't matter much with a boost controller since you just set it but running direct to the wastegate it might make for a noticeable difference.
Say you have a 12 psi wastegate and reference it to the intake manifold, it will open when the intake manifold sees 12 psi.
Same 12 psi wastegate referenced from the jpipe might result in 11 psi at the intake manifold due to back pressure between the j-pipe and intake manifold.

12psi
14b vs 16g
With same iats Will provide same power

stillrunning said:

You don't need to port your o2 housing unless you just want to really, there are limitations to how much you can port it.
But if you have it off and have the energy to burn why not, it shouldn't hurt anything.
Yes you just connect the wastegate to where ever you want to boost reference to be coming from.
Pressure at the j-pipe can be higher than at the intake manifold depending on how restrictive the intercooler an plumbing is. This doesn't matter much with a boost controller since you just set it but running direct to the wastegate it might make for a noticeable difference.
Say you have a 12 psi wastegate and reference it to the intake manifold, it will open when the intake manifold sees 12 psi.
Same 12 psi wastegate referenced from the jpipe might result in 11 psi at the intake manifold due to back pressure between the j-pipe and intake manifold.

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I see, once my mbc arrives, do i need a t fitting? 2 connect the actuator, mbc and jpipe/intake?

Sorry for all the newbie questions I'm new the dsm and all these turbo stuff but wanting to learn more aha

There was a discussion recently about why technical questions about these cars should really be left here and not scattered around other places like facebook and whatnot. So it's better that you ask as many questions here; future people can also find this topic when searching and possibly get answers. No harm in asking .

As for your last question, yes you should set the vacuum lines as stock for best results.

MBC > T > wastegate
invisible^
testJ-pipe/snorkel

i see, then just plug the nipple on the intake?
Wait should i run wastegate pressure or stock boost solenoid till my mbc arrives?

Wastegate pressure is less than stock boost solenoid. Using the stock boost solenoid will yield stock boost.

On a stock fuel system that's running well you can get away with 15psi safely. Just watch your AFRs in upper band when the flow demand is higher. A rewire could assist you depending on age of pump.

Looking at airflow ratings and depending on 16G (S/B/3), the 16G flows generally around 450ish CFM at 15psi, the 14B 405cfm, and the T25 even less than that.

The 16G moves more air mass than a T25 at any pressure due to the larger and more efficient compressor wheel. Due to the larger wheel, it's also able to provide this air mass at a lower temperature but, honestly, we're not talking 10C differences so we'll ignore temperature as we aren't overdriving either compressor.

In the end, more air mass translates to more HP but under your peak torque point we are arguing very small peanuts and not much different than a 14B. Butt dyno won't tell the difference and once you're in the upper half, though, the T25 being ~14psi stock will begin to fall off whereas the 14B or 16G will continue to cram air and still be underutilized.

My largest concern with a swap like this is by running a 16G the heavier rotating assembly will introduce more lag and worsen transient response from a T25. The 14B is a bit laggier than the T25, and the 16G is an itty bit moreso than the 14B.

So what that translates to is a potentially noticeable lul in your powerband when you start building positive pressure in your intake, especially at low rpm. I found the even heavier wheel on the B16G will start to really take off after the 5psi mark though, so a small should be a bit better than that.

*edited to remove talk about different flange on 2g manifold so as not to confuse new readers.. dont know what i was thinking as i know t25 has a td05 flange. i was considering a 2g mani for my years ago. Dont worry, my inexplicable dumb has been immortalized in quoted responses.

Evo3 or FP manifolds serve to increase lag by trading velocity for volume. Good for top end, not so much for low.. i still see 20psi by 3200 though in 3rd and 1-20psi in under a second in 2nd.. but that does no favors for fwd.

You may have to watch boost creep as previously mentioned in the upper RPMs. I've never had a problem keeping any pressure on a 7cm^2, except battling falloff at a steady EBC duty cycle.

You'll see a change in the upper RPMs but when just tooling around town, I'd wager you'll be slower. However, it's not for too long, right? So go nuts. In the end, yes, you can do it. For your purposes, no, it won't really be an upgrade... yet. =D

Mello said:

Wastegate pressure is less than stock boost solenoid. Using the stock boost solenoid will yield stock boost.

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Makes sense so itd be
Stock boost solenoid > T > wastegate
^
Jpipe