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After the cylinder head repair, The Shuttle made a return trip to Alamo Autosports' AWD dynojet at their facility in Arlington, Texas.  I had not performed any power tuning whatsoever since reinstalling the new head.  So, with Justen Simpson (of Celica GT8 fame) in town from Australia, another trip to the Alamo dyno was in order.

While the graph isn't as smooth as I'd like to see, it's becoming increasingly clear that the stock intake manifold and throttle-body are hindering power above 6000 rpms.  So, the next step is to either fit the JUN intake, or fabricate a custom unit from a 3SGE intake I recently acquired.

The only significate change to the enigne between these two runs is a larger turbine on the turbo from a .63 to an .82 a/r turbine.  Obviously, the .82 flows more air on the top-end.  I've also increased the engine rpm limit to 8000 rpms.  Oh man let me tell you this baby is singing a sweet, sweet tune at 8000 rpms!!!

The graph is somewhat misleading in that it appears the .82 a/r turbine spools faster than the smaller .63 turbine.  This is definitely not true.  The .82 turbine spools about 500-700 rpm LATER than the .63 turbine.   The graph iindicates otherwise because RUN034 from June 2003 was made in 2nd gear while RUN106 was made in 3rd.  HIgher gears load the engine more than lower gears, and this additional load creates heat that gets the turbo spooling faster.

Quite frankly, I don't like the added delay with the .82 turbine.  However, the engine has good torque for day to day driving when not in boost. But I notice the delay when I put the foot down and want power, NOW!  As a result, the jury is out on whether to the keep the .82 or I'll switch back to the .63.  Actually, I'm thinking of switching to a GT35R,but that's another story for another time.

Brice is the owner of Alamo Autosports.  He's got me beat for overall WHP but I have him on peak torque. Both runs are on 93 octane pump gas.

I'm thinking a custom intake manifold, 90 mm billet throttle body and full 3" intercooler to throttle-body piping should net me 40 - 50 whp and broaden the power curve after 6000 rpms.