i think turbo-wise, hes golden, but i definitely wouldnt have paired an 11mm pump with a K03 sized turbo..
i do realize that the 11mm rotor is a but big, but my thoughts are exactly what dan said. i plan on just down tuning it to run well with the gt1548. if it suks then ill do something else. i'm not looking to make big numbers by any means. i just want to be reliable with enough power to have some fun with. the gt1548 seemed like a good choice for quick spool and good power throughout.
Can't you use the 11mm head with 10mm springs and related parts, instead of turning down the pump itself?
bigger the pump head more high rpm risks right?
ive been told the 11mm heads are hard to tune. you either have it just below where you want it, or you screw it in a lil farther, and it makes a smoke screen behind you.. people who have owned 11mm pumps have told me to just avoid them all together, unless going for a balls-out build.
i would AVOID an 11mm head. a 9mm head is gonna do all you want to do with it, without having a 4000 rpm rev limit, dependant on the pump head its self. you can turn ~5600 on a stock pump head. you can do ~4000 with a 11mm pump tho. and that last 1600 rpm is where these engine really shine..
when I built my motor with the cummins pump I did some research into the RPM limit of the 12mm pump head, and found that the 4000 limit is for six cylinder motors.
four cylinder motors pump fewer times per revolution, so the safe rpm limit is higher(more like 6000)
I ran the 12mm pump as high as 5000 rpm with no issues.
as for tuning, with the larger pump head the injection event is shorter, making injecting large amounts of fuel require less advance.
other than that, they tune the same, just lots more clatter.
-Owen
a side question...
i have a tdi 10mm pump head,can i put it on a 1.6 gtd pump without changing other parts(pump cam for a 1.9 like usual)