2G Small 16g stock fuel pump & injectors

[Allen2g]

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.

Moreover, to run a 14B or 16G you'll have to swap to a DSM-flanged manifold and regardless of 2G, Evo3, FP, et al, this adds more lag due to decreased exhaust gas velocity vs. volume. Noticeable? Perhaps. 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

Aha no big deal, im taking the build slowly. Gna run stock boost till i get a pump and raise it to around 15

 

[curt-s]

Do you also have an intercooler/jpipe install kit that supports the different compressor cover as well?

When I was doing my SD table last year, I did continual runs from wastegate pressure to 22psi bumping up by 5psi each time so that I can dial in my rows accurately. It wasn't until I got past 15psi that I started to feel a difference from the 14B I ran a few years ago.

 

[Allen2g]

Do you also have an intercooler/jpipe install kit that supports the different compressor cover as well?

When I was doing my SD table last year, I did continual runs from wastegate pressure to 22psi bumping up by 5psi each time so that I can dial in my rows accurately. It wasn't until I got past 15psi that I started to feel a difference from the 14B I ran a few years ago.

yesir, i have the jpipe, is the Lpipe also required or just the jpipe?

 

[curt-s]

You need:

1) j-pipe
2) 90 degree "L" pipe
3) various crush washers
4) manifold-to-7cm turbine housing gasket
5) turbine housing to o2 housing gasket if they're currently apart
6) o2 housing to downpipe gasket
7) front and rear water lines
8) from-head oil supply line
9) oil drain line to pan

*edited to remove talk about different flange on 2g manifold so as not to confuse new readers.. dont know what i was thinking as t25 has a td05 flange.

you can get everything usually at a slightly discounted rate when part of a "2g install kit" for a 16g.

 

[Allen2g]

yeah i have everything needed, ill be running from the head and plugging the OFH.
&I'm reusing the water lines, just need to bend it apparently, gna reuse oil drain as well. As for the feed line, i have a new SS line from extremepsi.

 

[curt-s]

Then it sounds like youre pretty set up for now.

I went back and edited a few dumb comments in my posts, centering around how at the time i thought the t25 had a different flange. t3 maybe. No idea why, i was looking at a 2g manifold on my initial rebuild while still running a 14b. Maybe froze my brain temporarily in this -30C weather. Stupid winnipeg.
Dont want newer people to read that part and think it was true.
Im still confident in my other assertions, i swear


I personally run a ss line from the head and replicated the factory lines restriction. Hasnt failed yet.

 

[Allen2g]

Then it sounds like youre pretty set up for now.

I went back and edited a few dumb comments in my posts, centering around how at the time i thought the t25 had a different flange. t3 maybe. No idea why, i was looking at a 2g manifold on my initial rebuild while still running a 14b. Maybe froze my brain temporarily in this -30C weather. Stupid winnipeg.
Dont want newer people to read that part and think it was true.
Im still confident in my other assertions, i swear


I personally run a ss line from the head and replicated the factory lines restriction. Hasnt failed yet.

just realized fellow winterpegger!

 

[motomattx]

Then it sounds like youre pretty set up for now.

I went back and edited a few dumb comments in my posts, centering around how at the time i thought the t25 had a different flange. t3 maybe. No idea why, i was looking at a 2g manifold on my initial rebuild while still running a 14b. Maybe froze my brain temporarily in this -30C weather. Stupid winnipeg.
Dont want newer people to read that part and think it was true.
Im still confident in my other assertions, i swear


I personally run a ss line from the head and replicated the factory lines restriction. Hasnt failed yet.

That isn't necessary when installing a 13b-16g on the 4g63.

 

[curt-s]

Possibly not, but the original banjo had a measurably smaller orifice than the AN fitting that replaced it so I just necked 'er down to match.
At the very least it ensures the same volume reaches the cam journals and lifters as was originally intended by reducing that path of least resistance.
Rebuilt the 16g myself 20k km ago run at 21-23psi and it is still as tight as a drum, so doing so obviously was not detrimental to its operation.

 

[PlanZero]

I had my small 16g paired with a Evo X fuel pump (better than the 9 and can be found for about $50) and stock 450s for a long time. I didn't hit fuel cut until 15-16psi. AFRs 10.9 at wot. However every car is different. If you haven't already make sure you at least port the flapper hole so the WG opens as far as possible.

I was actually able to do the same with the T25 before the swap after I put on a 3" exhaust. T25 still spools quicker but falls flat real quick. I mostly drive in the city so quick spool is a priority.