How much horse power would I be at with...

[smh0101]

I was wondering if anyone could give me a rough estimate of how much hp I would get if I ran.

12psi (on the VF-11)
STi Yellow Injectors
Walbro Fuel Pump
'06 '07 WRX or Forester TMIC
3" Turbo back exhaust

Just curious more than anything else.

[Legacy777]

What are you using for engine management. You'll be worse off with the yellow's w/o engine managmene then you would be with the stock injectors.

[Matt Monson]

Yeah,
Skip the injectors. Also, unless your fuel pump is old and tired, skip the pump too...

[smh0101]

Okay so then what do I need to run 12psi on the stock turbo safely and keep it as a DD?

I honestly have no clue about engine managment stuff.

[wildacex187]

an intercooler will be fine for 12 psi i believe.

[smh0101]

Ok so how much of a power increase will that give me? (12psi & 3in Turbo Back)

[SemperGuard]

NNot much, replace the turbo if you want more power.

[Matt Monson]

12 psi will probably put you around 200 at the crank. If you install an FCD and go up to 14psi it will be more like 220+/-

[smh0101]

So what are the limits of the 5mt?

It has 147K mi on it so I dont want to do to much.

Am I safe running 200hp @crank with this tranny?

[Matt Monson]

Sure. That tranny can handle bazillions of HP as long as you don't abuse it...

[smh0101]

Define abuse it...

I have never dumped the clutch... Shifted really hard and fast (aka faster than the synchros)...

[greg donovan]

12 psi will probably put you around 200 at the crank. If you install an FCD and go up to 14psi it will be more like 220+/-

at what point do you need to start adding fuel and worrying about A/F ratios?

[555BCTurbo]

at what point do you need to start adding fuel and worrying about A/F ratios?

Depends on your turbo setup...


With my VF8, my wideband starts to read a wee bit lean around 14-15 psi without any correction from my Perfect Power.

[SemperGuard]

Define abuse it...

My definition of abusing a 5mt is attaching it to any engine making more than 200 lb-ft.

[Matt Monson]

Define abuse it...

My definition of abusing a 5mt is attaching it to any engine making more than 200 lb-ft.

And my definition of that tranny's power holding capability is much higher. This tranny is no different from the early WRX tranny in strength and those cars came with 260ps, as 5mt RS's came with 250ps. There's a safety factor built in there. I personally don't think there's any need to worry about the tranny until somewhere up around 300ft/lb of torque.

As for defining abuse? Dropping clutches, forced shifts faster than the synchros can shift, high revving down shifts using engine braking. These are things that do happen in a racing situation, but if you aren't doing them on the street, your tranny will probably be fine for another 50k mi or so, even with more power.

As for the fuel question? Different guys have different results. Many people don't mess with the fuel at all at 14psi on the stock turbo. Others enrich. It's kind of inconsistent what you see around the country and likely is influenced by altitude, temp and humidty. For example, I live at 5000ft. Because of the thinner air, my car already compensates and runs 10psi on it's own. 14psi up here isn't the same thing as 14psi in San Francisco...