Subaru Forester Owners Forum banner

1 - 12 of 12 Posts

·
Registered
RIP 2005 FXT 5MT
Joined
·
938 Posts
Discussion Starter #1
So I recently installed:
  • VF39
  • STi TMIC & Hoses
  • STi BOV
  • Walbro fuel pump
  • STi ported exhaust manifolds
  • Grimmspeed crossover pipe
  • Cobb VF39 93 oct base map
I previously installed:
  • Grimmspeed Up-pipe
  • TurboXS catted stealthback (2.5" reduction last 5" before axleback)
  • WBR 3" FXT axleback
  • Perrin Crank pulley
  • Perrin aftermaf hose
  • Snorkel delete w/ hose to fender
  • Iridium +1 colder plugs
I'm going to have my FXT tuned soon and I wanted to know what other mods I should get. I'm on the base VF39 93 Octane map and I'm seeing a solid 15 psi in 4th and 5th.

I know that the major limiting factor at the moment are my injectors but I don't want to swap them out until I have a different daily driver. And I want my FXT to reliably last another ~50K (85K currently) before I turn it into a beast. I don't care about noise but I do want to keep my cat. And it rains/floods to often in Houston to run a CAI.

Therefore, I'm thinking of getting 1 or 2 of the following but I would like some help:
  • Grimmspeed BCS
  • Short Ram Intake w/ heatshield (SPT or K&N)
  • Swapping the TurboXS midpipe to a full 3" version
Any suggestions? I usually don't make posts like these but I would like to hear from my fellow FXTers. Oh, and I have done my research (i.e. I've seen the TurboXS 2.5" vs 3" midpipe NASIOC thread, millions of intake threads, etc.)
 

·
Premium Member
04 Acura TSX the slick 6 speed
Joined
·
2,355 Posts
I got a tune 2 weeks ago, and asked the guys at TopSpeed what would be next in the power mod department. I have about the same mods as you, and Doug told me that unless I spend a big chunk of money, I'm only adding a few HP here and there, which wouldn't be too noticeable.

So I'd say you've got the majority of the power you're going to get unless you really spend some money.
 

·
Official sf.org decal guy
2006 FXT
Joined
·
12,367 Posts
As you already said your injectors are the weak point right now. But I have to totally agree with greentrees. I was where you are now and the next step is a bigger turbo. I went from a VF34 to an 18g and had to do injectors. My next will be a ported intake manifold, turbo inlet, tgv deletes, Grimmspeed bcs, and a front mount intercooler.
 

·
Premium Member
2007 Forester XT 4EAT-VTD
Joined
·
2,138 Posts
I got a tune 2 weeks ago, and asked the guys at TopSpeed what would be next in the power mod department. I have about the same mods as you, and Doug told me that unless I spend a big chunk of money, I'm only adding a few HP here and there, which wouldn't be too noticeable.

So I'd say you've got the majority of the power you're going to get unless you really spend some money.
Yes, that is where I am at now. My mods are very similiar to yours exept I'm running a larger TMIC (Perrin) which did help pre-boost throttle response. Since my last tune, I've added the Perrin TMIC, Samco turbo inlet/afterMAF hose and a high-flow air filter in the stock box. I'm going back for a tune tweak in 2 weeks so I will see if I gained anything. I'm also taking the GS EBCS with me in the event the tuner thinks it will be an advantage.

No doubt my limiting factor is now the VF48 and injectors. If we had E85 up here in NH I'd install larger injectors and get tuned for that. Until that happens, I'm sticking with the hardware I now have as the car is more than fast enough for a street-driven car.
 

·
Premium Member
04 Acura TSX the slick 6 speed
Joined
·
2,355 Posts
Yes, that is where I am at now. My mods are very similiar to yours exept I'm running a larger TMIC (Perrin) which did help pre-boost throttle response. Since my last tune, I've added the Perrin TMIC, Samco turbo inlet/afterMAF hose and a high-flow air filter in the stock box. I'm going back for a tune tweak in 2 weeks so I will see if I gained anything. I'm also taking the GS EBCS with me in the event the tuner thinks it will be an advantage.
I'd be very interested in the results, I hope you post a before and after thread so we can see the numbers!
 

·
Registered
2004 Subaru FXT MT
Joined
·
1,841 Posts
I still don't like seeing tuners run 100% IDC, and that is what you are going to get with 500cc injectors on a VF39, if you push it. Not at 15 psi, but if you have your tuner push it up to 18-20 psi, you will.

Actually, the stock box will choke it off a bit, so it might not be that big of a deal. So will the 2.5" exhaust. So you are probably fine. But if you had wide open exhaust and a CAI, and wanted to push it, I would suggest stepping up the injectors.
 

·
Premium Member
04 Acura TSX the slick 6 speed
Joined
·
2,355 Posts
19.3 at 3200 tapering off to 14.5 at redline. You can mouse-over the line to get the numbers.
That's cool, and lots of boost. I compared our graphs, it's amazing how different they are, I bet your car feels very different from mine, even with such similar mods! Both are very smooth curves though. Can't wait to see your new dyno!

OK sorry to go off topic!!!
 

·
Registered
RIP 2005 FXT 5MT
Joined
·
938 Posts
Discussion Starter #11
Thanks for the responses guys.

But I'm going to stick with what I have right now... since my wife told me that we have our 1st little one on the way!
 

·
Premium Member
04 Acura TSX the slick 6 speed
Joined
·
2,355 Posts
Thanks for the responses guys.

But I'm going to stick with what I have right now... since my wife told me that we have our 1st little one on the way!
I think that's smart. Family > Forester, I always say. I'm sure your wagon is plenty fast.
 
1 - 12 of 12 Posts
Top