RB engine with multiple restrictors
 

I have an rb25 and plan on putting in 2 1.5mm restrictors into the block but is it possible to go with a smaller restrictor in the future once I go to a different oil pump?

Generally you peen the hole a bit so the restrictor can't come out. You're probably better off installing them once. Why would you change them when going to a different pump? Does the new pump generate more pressure? If so, you can simulate it by shimming the relief spring.

There are various pumps that increase oil volume over others.

http://www.skylife4ever.com/2014/08/...-pump.html?m=1

There is a chart out there that recommends specific restrictors with specific pumps based on your setup.

What would be considered too much pressure?

I have an N1 pump with spool import gears and 1 oil restrictor blocked. the other is left stock.

It's been awhile but I believe I was seeing 7-9bar oil pressure on a cold start and it gets over 7bar on WOT if I remember correctly, it's been a few years.

That sounds like good pressure for an RB to me.

Good to know! Remembering now I also went to the +.001 bearings on rods and mains.