Just a general question about boosting the legacy 3.0 H6. How sterdy is the block and heads in terms of say 10 PSI boost? Also if that seems impractical would it be reasonable to up the boost on the 2.5GT motor to about 20 PSI?

Thanks for your help.

Depends. Are you replacing the pistons to lower the mechanical compression ratio?

I know a guy who had a 2001 Outback H6 and wanted to boost it (only to about 7 or 8 psi as I recall). The tuner talked him out of it when he found out that the engine has a single exhaust port for each bank of 3 cylinders. He was concerned about temperature rise inside the head (I believe).

 

IMO, you are taking your chances boosting the 2.5L engine, unless you do a full build up. You might try your luck on finding a turbo'd engine from a wreck, or an importer.

 

Commuter

with a turbo kit on the 6 cyl.. it wont last

we've seen it on the SOHC 2.5's for years now.

even at 4, 5 psi - the shortblock melts.

 

proper way to turbo it is to do an engine swap

 

jamie

There is a guy on ebay that imports the goooood turbo Subaru engines. Do a search and you will most likely find it.

Hi,

 

Thanks for the info. Anyways could you find out from your friend exactly what his tuner told him? I'm alittle confused because I thought the H6 was a DOHC 4 valve per cylinder. Well if you could let me know that would be extremely helpful.

Thanks

Hi,

 

Thanks for the info. Anyways could you find out from your friend exactly what his tuner told him? I'm alittle confused because I thought the H6 was a DOHC 4 valve per cylinder. Well if you could let me know that would be extremely helpful.

Thanks

I can't remember off hand if the engine is single or double overhead cam (but single I believe). I'm sure it is 4 valves per cylinder. However, none of that is really relavent to my comment. The exhaust gases from all 3 cylinders are brought together inside the Aluminum head to a single port before they go into the exhaust manifold. That's all I was commenting about. I have not personally verified this, but I have not heard to the contrary either.

 

Commuter

Hello again,

I understand now what you were saying. I didn't get that one port deal but I do now. So would you think about building a jdm STI motor and droping that in instead would be a better idea or is the whole concept of beefing up a legacy kinda ludacris? Well let me know what you think.

Thanks again