06 WRX versus a 2000ish Pontiac Grand Prix

[DTR rex]

The 06 should have came with atleast a vf-39, but that would gap the STI pretty good power wise.

The problem is precisely that gap. If you move the wrx upto a VF39 then the STi needs a bigger turbo. problem is that the next thing worth even having would be an 18G. This would be nice because then the STi would be putting out over 300whp stock, but it would hurt long-term reliability for the car.

I think the wrx needs a turbo that can produce ~ 230whp stock (around stage2 wrx power, but with more breathing capabilities of a slightly larger turbo) and the STi needs a turbo not quite as large as an 18G that can produce ~ 280whp in stock form.

[302@12psi]

I'll met you in the middle and just say toss on a big 16g for the wrx and detune it. Then toss on a td-06 18g and detune it for the sti. Both can hold decent boost till redline, and be tuned for longevity. All it would take is a protune to be pushing MAJOR power on each motor.

How does the vf-41 (Legacy GT turbo) do on the 2.5?

[John M]

The Legacy's VF40 isn't a great work of art either. Mine grenaded recently (13k miles; never over 17 psi) and others (bone stock) have also lost turbos, so its reliability is becoming doubtful. It spools nicely and can hold boost till around 5k rpm, then it starts to fall sharply.

This is the key area (other than improving the engine's volumetric efficiency) where any turbo upgrade is beneficial -- it allows you to hold boost till redline. Without raising boost one bit, you can substantially increase the area under the curve and the result is a much faster car, all without stressing the engine any more than it already is from the factory.

[ansonowicz]

I'll probably leave turbo upgrades alone for a while since it's a gauranteed warranty buster, but it would be nice though.

You will NOT regret going stage 2. Stage 1 smoothed things out a good bit. Stage 2 was just almost on par with stock STi.

[DTR rex]

I'll met you in the middle and just say toss on a big 16g for the wrx and detune it. Then toss on a td-06 18g and detune it for the sti. Both can hold decent boost till redline, and be tuned for longevity. All it would take is a protune to be pushing MAJOR power on each motor.

How does the vf-41 (Legacy GT turbo) do on the 2.5?

That sounds good... REAL good, in fact.

But with a detuned big 16G the wrx would be making reasonable power, but what about mods. With that turbo detuned, you could add full exhaust and EM (essentially what a stage2 is now) and be pushing nearly 300whp which would cause problems with the tranny I would think.

Same with the STi. If you have an STi pushing 290whp or so on a detuned 18G and then you go "stage2" and add exhaust and EM you could be pushing nearly 350whp and reliability is questioned.

I guess in the end it would work out though. People that go stage4 now see the same issues, and if the car come stock with that type of power, maybe stage2 wouldn't be a necessary.
I don't know, I know what I want to say, but I am not saying it very well, lol.
One other thing, a turbo that large in a wrx would require a larger intercooler, stronger gears and larger diameter exhaust as well as larger brakes to support the 16G and might drive costs up a grand or two.

Just a thought. I would love to see subaru take some steps towards making this discussion a reality though.

[302@12psi]

Well as for the "when you mod" point that is really null and void as Subaru wont warranty it anyway.

It is a good point about having to upgrade the wrx tranny, but to be honest we are ready for that anyway. Give us the Spec-B 6 speed with non DCCD on the wrx and 16g with upgraded intercooler. Stock fuel system can run this on a detuned set up easy.

As for the sti the evo comes with a more then capable stock turbo so we cant we?

[Blue_Eyez_]

To me this seemed kind of weak. I really feel like this car is slow. I am used to an 02 cobb stage 2 wrx, and the more I drive this (06), the slower it feels to me. I know it's just the but dyno, but man I need stage 2 now!

My stage 2 feels slow...