I've done some searching and still can't make my mind up to be honest.

As I've posted else where a simple she'll replacement on my STI UK has become a full rebuild with uprated bearings, new crank as that's marked heavily and I've ordered wiseco pistons and manley rods today as the pistons were scored slightly as well.

So do I need an uprated one when going for around 450bhp or will the stock STI item do the job?

Answers on a postcard are fine, but here is preferable

 

If its an engine rebuild then yeh defo replace the pump, a standard one will be more than up too the job.

 

A stock one is 10mm and may not flow enough oil at 450hp
11mm uprated one with valve mod, from advance automotive. £180 ish

 

As mentioned definitely replace the pump.
As you are probably aware builders tend to use 10mm 11mm 12mm.
Bigger is not necessarily better.

It is all down to the spec of the car, as to how much oil needs to flow. For example does it have AVCS heads? What size oil cooler? and so on.

What bhp you run has nothing to do with it. However higher BHP cars tend to have bigger pumps as they tend to have a bigger spec with more oil to flow.

You need to post the exact spec of your build up and then someone can advise to what size pump you sould go for.

Cheers
Steve

 

Id have a read about the uprated / modded pumps. Something about the pressure relief valve sticking and causing oil pressure drop. Stick to standard. I am running 440 and having no pressure issues with 15w50 oil.

 

10mm rcm uprated oil pump is what I have on my car no need for the 12mm unless you have avcs heads or huge oil cooler maybe

 

I have avcs and going for 450+ so have gone for a 11mm pump

 

Ta very much gents. Decided to get a new genuine 11mm oil pump so that should do the job.

Just waiting for my rods and pistons to arrive now and it can all go back together.

 

some of the "modified or uprated" pumps are nothing of the sort and IMO aren't worth the costs involved - we tend to use/supply either OE or RCM variants (correctly modified)

most pertinent thing is to select the correct size for YOUR application..........

all in stock at very good deal costs

 

As already said, don't go too big, alot of People think a 12mm Cosworth pump is the ultimate, but the 12mm pump is designed for the extra qty or oil required to operate the dual avcs (Hatch STI). Ive seen a few engines go bang becuase the relief valve has stuck open. This is because it's trying to pump more oil than the engine requires.
11mm std Subaru is my suggestion for all but dual avcs engines.
PS check the back plate is tight ;-)

 

The exact reason a friends failed, he was also running an oil cooler and it still stuck open!

I am running the standard 11 and will be running a 16row. Can always jump from 15w50 to 15w60 if I seen an all round pressure drop with the oil cooler

 

What are your bearing clearances Daniel?