250rwkw At The Wheels Woohoo!

[The Alchemist]

Hi R31 Nismoid, like I said, I'm only sharing information and details of what happened.....This was our experience only.

What do you think could have been causing the restriction then?

Only the head and the wastegate was changed between dyno runs. turbo remained the same as did the boost . Bottom end wasn't changed, neither were the manifolds (inlet & exhuast).

What do you think?

cheers

[The Alchemist]

could have been valve spring float....

[R31Nismoid]

so you were running the same spring rate between two different sized gates?

[The Alchemist]

dunno, like I said we just dynoed it and the owner had his own tuner....

I had a good overview though of what was going on.

The larger wastegate was a Tial 45mm boost started at 12psi at around 2500rpm gradually increasing to 17 psi by the end of the run at 6200rpm. It did exactly the same with the smaller 38mm gate when the head was standard.

Spoke to the engine builder the other day and he said that the std valve springs weren't coping causing the lose of the valve following the cam at high rpm....... and hence the power maxing out > a possible explanation maybe.

The modded head had solid buckets like on a GTR head, heavy (new) valve springs, special cams and valve seats fully flowed head etc.

All I saw is that it made a massive increase in power at the same boost....it appears just by sorting the head and fitting a larger gate.

ALL good!