Holset hy35w technical discussion?

[Thumper]

Ok I was having a discussion over on e30tech.com They over there feel the hy35 with its 9cm compressor housing is too small and you need to run a hx with its 12cm or the turbo will be out of its sweet spot at upper rpms. I have said that I know of cummings running these up 35psi+ and stock they are running 18psi so I don't believe 20psi on a 2.7 will get it anywhere near out of its sweet spot. Their arguement is that since I am spinning the engine twice as fast as the diesel engine this came off of that the gas engine needs more air than the stock diesel engine. Even though the stock engine is a 5.9l diesel and the bmw motor is a 2.7l

 

I know diesels don't burn the entire amount of fuel per combustion cycle but it still injests 5.9l's of air per revolution correct? Also what do you think has more exhaust energy a 5.9l diesel engine at 3k rpms or a 2.7l gas engine at 6k rpms. I would think the 2.7l just by alittle bit not alot since more of a complete combustion. Although more compression in a diesel engine so more exhaust pressure? The discussion is long dead and i'm not looking for ammo just wondering. Thanks

[rztmartini]

calculate cfm flows from both engines and that should give you a comparison. the claculations are in the turbo sticky somewhere...

[Guest e36'n]

I just bought two HY35's so I hope so.

 

I researched these for a couple months and they should be a turbo that will reach full boost (8.5psi for now) around 3k rpms, be efficient up until about 23psi and make up to 450whp.

 

People who use these seem to love them. A close comparison would be Precision's SC-6031E http://www.precisionturbo.net/turbochargers-display.php?company_id=101795&category_id=3026.