View Single Post
Old 01-31-2012, 04:50 PM   #130
Maxwell Power
Former Vendor
 
Member#: 190729
Join Date: Oct 2008
Chapter/Region: NWIC
Location: Marysville, WA
Default

There are a handful of things that need to happen to push a Subaru motor that high.
1. Intake manifold. We will need the plenum volume and short fat runners to feed enough air in the engine. Also, the firing order of the engine makes proper intake manifold design a little tough.
2. Cams: Right now there isn't a cam profile made for a 10k rpm engine. Custom cams would be required as a minimum.
3. Head flow: While these heads don't flow a ton, there are big differences from port to port. 20% difference in exhaust ports from the factory. At 300hp that's a significant difference in flow, but at 900hp we're really talking about a major tuning issue. Our porting program is designed to provide less of a difference in flow between cylinders while still removing as little material as possible to provide good velocity.
4. Cooling: the STi water pump won't cut it. The 2L water pump is a good pump that experiences less cavitation at high rpm. I think it is possible to expand on that pump a little to increase flow output. Getting more cooling to cylinder 4 is also a priority for us.

As Vicious pointed out, a larger hotside is required. This is a given. As cam size goes up, so does the hotside. The challenge is getting as much air in and out of the engine will at the same time minimizing overlap. In order to do this, you need a lot of lift as these heads really flow well at almost 12mm. The issue with that is then trying to prevent valve float at such a high rpm with a big cam. Increasing spring pressure increases parasitic loss...

It's a big circle, really.
* Registered users of the site do not see these ads.
Maxwell Power is offline   Reply With Quote