[ValvetrainEngineer]

You guys seen this little upgrade yet? Not in my plans just yet but still interesting...

http://www.cosworth.com/shop_item.php?productid=345

[Black_Sun]

Drool.....Drool.....

[Tortfeasor STi]

Cosworth is a well respected name and builds a lot of professional race cars. It sounds like they have taken an STi casting and ported it and done a valve job on it. You can probably get this done to your existing heads by a reputable engine tuner or machine shop for less than the near 4 grand they want for those heads. Ofcourse that means finding one with sufficient experience which might take some time. But the potential cylender head changes have is huge, but probably the most expensive way to get the power you are looking for. If I was going to buy a custom built bottom end I might get it put together with heads like this and then get a beutifull turbo and make what is essentially a time attack race car. But I can, in no way, afford that. Ever.

The coolest thing about heads with huge flow is that you can make more power with less manifold pressure than you can with stock. After all a turbo is nothing more than an air pump, and boost is simply a measure of the engine's inabillity to ingest all the pumped air in one intake stroke, i.e. back pressure. So the more efficient the engine is before manifold pressure is applied, the more air it can ingest each combustion cycle, the more power it makes durring the power stroke. Want to race the z06? perhaps we have the cylender head for that engine here. Want to build a fast street car... Save your money.

[Ol'SaltyBastard]

I agree with ^^^^^^^^^.


Nice, but way too much money for what you get. People who specialize in cylinder head modifications will pretty much agree that though the design may vary, a head is a head. They all do the same thing (the function of the head, not the modifier.)