Talk about engine building here. New products, tricky questions or showcase your work - If it's engine building related it's welcome here.
i'm almost done sourcing all needed parts for my RB30/25DET build
setup so far :
Nissan RB30 block and cranck
Nissan RB25 gen1 head
Genuine Greddy plenum with nissan Q45 throttle body
aftermarket rods and pistons
Garret gen 1 GT3582 0,82AR on a modified Greddy Trust exhaust manifold
so question is what size gate should i run on this setup ? Engine will be in my 200sx street car so wont always run high boost.
I've tuned several engines with similar specifications. The answer is possibly more complex than it seems as the required wastegate sizing also is dependent on the way the wastegate is plumbed - For example if the exhaust flow into the wastegate is smooth then you can often get away with a smaller wastegate than if the wastegate is plumbed in a way that the exhaust gas needs to perform a 180 deg turn to get out the wastegate.
In reality you always want to attach the wastegate in a way that flow into it is optimised anyway for the best control of boost pressure. On that combination I'd recommend a 45 mm wastegate.
manifold is this greddy , so not the best flowing gate i guess
Yea that's not entirely ideal. How good the control of boost will be will depend on the wastegate size and how restrictive the exhaust housing is too.