JDM 2007 Legacy GT Spec B Tuning Options

[DylanGC]

Hello,

 

I have a 2007 JDM GT Spec B, a six speed manual.

 

I would like to have a little more power and I was wondering what my options are?

 

I have been told that a tuning session on a dyno could achieve around 310 to 330bhp without any mods.

 

Is this correct?

 

The car has a VF45 turbo and is of course a twinscroll.

 

Thanks

 

Dylan

[Andy_Mac]

Are you saying 310hp at the flywheel?

Assuming 25% drivetrain loss would give you around 230wheel hp which is a tad ambitious sadly.

Had mine e-tuned by Cryotune and got around 205wheel hp at a safe boost level for stock.

Same specc'd car as yours btw.

 

Really depends if you value safety. Could probably get 230 with 17-18 psi but without supporting mods it wouldn't be advisable. Have you ever looked at the downpipes for these cars, absolutely crap design, would at the very least get an aftermarket downpipe if you want real performance gains.

 

Whereabouts in the world are you anyway, wouldn't imagine you are US based like most on here?

[DylanGC]

Are you saying 310hp at the flywheel?

Assuming 25% drivetrain loss would give you around 230wheel hp which is a tad ambitious sadly.

Had mine e-tuned by Cryotune and got around 205wheel hp at a safe boost level for stock.

Same specc'd car as yours btw.

 

Really depends if you value safety. Could probably get 230 with 17-18 psi but without supporting mods it wouldn't be advisable. Have you ever looked at the downpipes for these cars, absolutely crap design, would at the very least get an aftermarket downpipe if you want real performance gains.

 

Whereabouts in the world are you anyway, wouldn't imagine you are US based like most on here?

 

Hi,

 

Thanks for your reply.

 

I am in the UK.

 

I would like a reliable performance gain and do not have any problems with having aftermarket parts on the car.

 

I am getting conflicting information from various sources about power gains for this car.

 

Some say it will easily make around 320bhp, at the flywheel, with a good tune. Others say it needs supporting mods.

 

I am not so sure what supporting mods are required to achieve a reliable 330bhp at the flywheel.

 

Can you give me an idea of what parts I would need to fit to start seeing some good figures?

 

Thanks

 

Dylan

[Andy_Mac]

I'm actually in the process of pricing up parts to go for a stage 2 cryotune. I'll be getting an aftermarket downpipe, both intake pipes (after maf, under manifold one) a 3 port boost control solenoid and a better bpv. Not all those are necessary, could probably get it done with just the downpipe but i'm just trying to future proof things.

 

Our downpipes pretty much look like this so any fine tuning at high boost levels will surely be alot harder than with one that gives the wastegate gases a clear path to take. Throwing more and more boost at a system that is very obviously bottlenecked by this exhaust isn't the smartest way to do it.

 

http://i1149.photobucket.com/albums/o594/andy_mac1/DFDD6465-40EB-4832-A255-E013BA60CE49_zpsur0va43q.jpg

 

Bit of a rough job i know but you could always decat the downpipe and get someone to alter the opening and widen it to open up the wastegate area. Though, without being tested by a fluid dynamics engineer you could end up making things worse.

 

Also what fuel do you get there, will make a huge difference.

 

All in all depending on your tuner it could possibly be done but it'll be pushing things harder to get to that point than it would with supporting mods.

[DylanGC]

I ended up getting a Milltek turbo back system and a cosworth panel filter.

 

Other mods are Forge Motorsport turbo actuator and GFB BOV set at 50/50.

 

Made 326bhp at the fly after remap.

 

http://i.imgur.com/z9owrWNl.png

[Andy_Mac]

Nice result, so about 185kw at the wheels, must be happy with it.

[DylanGC]

Yes, its driving so much better. Very happy with the results

[Clam129]

Is this something a BOV could help with? I was looking into upgrading my turbo on my 2007 ej20 and was advised on a BOV. I will be getting a turbo back upgrade before the turbo upgrade but wouldn't a BOV help with this problem?

[Andy_Mac]

Carefull with the turbo back upgrade. The Legacy twinscroll flange is different to the style that comes with aftermarket Subaru turbo's. You have a particular turbo in mind?

You only need a better BOV if pushing the boost past 19-20psi. Anything below that and the stock one will in most cases still cope. What is this problem that a BOV might fix?

[Tuning Alliance]

We can help you out with a good etune. Cryo is no longer etuning.

 

Send us a PM can get the ball started.

 

-Brian

 

 

EDIT: Opps, I got had 2015 bumped post my bad.