I'm building an EFR 6258 1.8l turbo na track car. Motor is back from the machine shop and I am getting ready to purchase more parts. Can anyone give some insight into what boundary S2 oil pump (shim setting) I should go for? I have a bp-1 block, bp4w head, forged rods/pistons, and kept the oil squirters. I also plan on running an oil cooler. Hoping to get things right so I only have to install the motor once......for a while.... I can purchase it assembled with 60, 66, 72, 78, 84, or 90 psi shim stacks. Thank you in advance.


https://boundarypumps.com/shop/mazda...bled-oil-pump/

 

I would do 66 or 72 max. EFRs don’t like a lot of oil pressure, so best not to over do it. With any of those options, I’d still get turbo smart’s little inline pressure regulator

 

I have the same exact setup as you, I currently have the s2 pump 72 psi. This is what fab 9 recommended to me worked out great .

 

Thank you curly/maison. Super helpful.

Maison are you running the 72 shim with the pressure regulator curly mentioned as well ? I thought the Efr already had a restrictor built in. Thank you.

 

I don’t have any regulators . Didn’t see a need to honestly

 

Restrictor yes, but you still want to feed the restrictor no more than 40(?)psi. Might be 60?

 

when I emailed Boundary about my EFR6258 on my VVT motor, they recommended the 72psi shims.

 

I bet Borg Warner would recommend the 60psi.

 

I heard from Boundary as well. The recommended the 72 shim everyone above mentioned above. With more or less depending on if you are running loose or tight bearing clearances.

 

So you want to run more oil pressure when it's cold? Because most engines won't hit 60 lb hot unless the bearing tolerances are too tight. So the only thing you're doing is stressing the oil pump more during warm up.

EFR turbos are extraordinarily sensitive to oil pressure and crankcase pressure. Just remember this discussion if you ever have oiling problems with your turbo.

/slightly passive-aggressive Sixshooter

 

I do run an oil pressure reducer (OPR V2 Turbo Oil Pressure Regulator • Turbosmart) to keep my EFR seals happy.

 

thank you. it’s making sense now. It doesn’t make sense to increase oil pressure on cold start up with a higher oil pump relief valve setting.

I’ll plan to run a regulator as well.