I would be very interested if any members could give me an opinion on the above two turbos.

I have two Foresters.

The first a 2005 XT which I have modified to around 300hp using an SC36 turbo. Spool up and top end are great with this turbo, I love it. The softer cams on the 2005 2.5 XT mean that it will never get to the power that the turbo was designed for though.

I've also recently bought a Forester STI which has the VF41 turbo. Im intending on building this car up to be a bit faster. I'll keep both cars in the short term, my original XT isn't worth much now anyway!

The question is whether its worth the time and money to swap the turbos over. Would the SC36 be a better turbo than the standard VF41 on the FSTI? I know from the forester forum that the FSTI is capable of 330 to 360hp on its original turbo, so there may be no point.

What would members expect the STI 2.5 engine to produce with the SC36 and would it be worth it? I'll be fitting an HKS exhaust system and larger Hyperflow TMIC.

Thanks

 

Personally for what you'd gain I'd say it's not worth it. Better to opt for the 40 or 42 as they'll see you north of 400bhp. Bear in mind you'll need to upgrade the fuelling and I'd go front mount too. Plus you've got the dreaded 2.5 issue too.

 

Yes, there is a limit to how far I dare go! I went with the SC36 on the XT because its still give the lower down spool up of a smaller turbo. Whatever the FSTI ends up with its got to be a felxible, tractable engine. No point having all top end power, its a forester after all!

If I got the car to 360+hp then I would be very happy. Those numbers are enough for me.

 

I'm sure with the right mods your vf41 will get close to 360 plus a fair wedge of torque.

 

Thanks, the more I read the more I think the swap is not worth it. I'm thinking I'll leave both turbos where they are and either be satisfied with the vf41 at its max or find a larger turbo.

 

My previous classic was a 2.5 with a sc36 on and with supporting mods was maxed out at 354/350