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copbait73 copbait73 is offline
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Join Date: Nov 2003
Location: Chesterfield IN
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Originally Posted by 911st View Post
Yes, those are factory GT2 Evolution headers and they are gorgeous!

I do not think the primaries could be much shorter and accommodate a nice collector and waste-gate circuit.

Interesting how they carefully transition the WG's for efficient exiting.

I wonder--if we are expecting a substantial amount of exhaust gasses exiting the WG circuit at WOT, if the same principles for reducing turbulence and promoting good flow should be extended to it to.

Usually the WG systems seems more like an after thought on most set up with us just sticking a 90 deg junction off the secondaries may or may not have an effect.

Could this offer some additional performance especially with the smaller turbine quick spool turbos that tax the WG even more.

Just a thought.
Any shorter and they wouldn't be equal length primaries. Equal length was considered important so here you have them.

The importance of flowing W/G has been recognized since the early 70s, mainly from work on Turbo Indy cars in the late 60s. I have a Crane Cams Turbo book from '75 showing it. This was made a science in the early to mid 80s with F1 Turbo motors. Also, running "spec" turbos CART champ car systems have beautiful header design with extra special attention to W/G flowing. You find very large piping off the secondary pipe going to equally large W/Gs.

As an aside, probably the best application of a W/G is 30degrees tangential on the turbine housing ported just upsteam of the volute throat. This was seen on many of the later F1 cars. Impossible to package on a 930 but interesting as best practice and you see the principle applied to the secondary pipes on the system above.

Last edited by copbait73; 02-04-2010 at 05:21 PM..
Old 02-04-2010, 05:18 PM
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