FA20 Engine Oiling, Bearings, and Starvation

[Calum]

Originally Posted by Element Tuning

Yes and no. Higher oil temps always drop oil pressure. The problem is that the OEM oil pump isn't large enough to supply the required oil pressures for substantially higher than OEM hp under normal driving conditions.

So while an oil cooler will help lower oil temps and help keep oil pressure higher you'll find that most of those with oil coolers are getting only about 10 psi more oil pressure so it does help but let's get real here. Those guys tracking their cars with oil coolers and that have good data are either NA or may have 280 hp with a supercharger. So 50-60 psi is probably going to do the trick but we need a solution to run 400, 500, and 600 hp.

If I can get 70-75 psi on the street consistently I would be happy for our customers running 400-500 hp. For 600+ I would like to see 75-80 psi. If I added an oil cooler to what I've done along with the heavy weight oil I think I'm right there for a reliable high power street car.

Now track cars running 400+ hp will not be able to keep oil temps in the 210-230 F range at all. 260 is going to be realistic for a track car with a cooler so we need that oil pressure in the 85 psi range on the street so we can handle that viscosity drop while racing (we see about 15 psi drop on our STi race engine).

Oh and by the way I'm running 15w50 Red Line as I knew I would still need the extra viscosity to increase pressure.

For those guys in that ~280 who range what viscosity do you recommend? And for the NA guys?

[Element Tuning]

Originally Posted by mike the snake

I'm aware of accusump.

I was thinking of making a "poor man's dry sump" and trying to solve the oiling issues Element Tuning is having without spending thousands on a real dry sump system.

A redundant, dual pump (stock pump AND cam driven aux pump) with separate pickups in the pan, and maybe a small sump on the aux pump, might just give the extra pressure and volume needed at high G, high RPM loads, and offer extra protection in case one of the pickups loses suction at high G's.

The aux pump could even be plumbed in at a different spot, maybe where it's most needed, otherwise it could be plumbed in at the sandwich plate maybe.

An in-line, one-way check valve on the aux pump would ensure one pump would always be working, and a small sump on the aux pump would ensure no pressure loss even when both pumps lost suction at the pickups in the pan at high side G's.

Mike, We have actually thought of running an external oil pump as they are used on race engines. The pump needs to be much bigger than you think as there is a ton of volume needed. The OEM pump is actually very large and high volume but at the same time Subaru decided to feed the heads simultaneously increasing the volume demands.

The issue that needs to be overcome when trying to add a supplemental oil pump is how to keep it from working against the oem pump.

An external pump can replace the oem pump entirely.

[Element Tuning]

Originally Posted by Calum

For those guys in that ~280 who range what viscosity do you recommend? And for the NA guys?

Ok so this is where temperature and viscosity can have a conflict. You won't need a ton of oil pressure for N.A. so in that application too much viscosity can cause higher oil temps when higher oil pressure isn't really needed. At 280f the grade of the oil is way lower than its rating.

As a general rule of thumb tightening up the viscosity range is better so don't go to 0w-40 as I've had very poor results with that. I personally raced N.A. on 10w30 and thought that worked great for me as I was ru ning a little more power, e85, and higher RPM.

Thanks,
Phil Grabow

[Element Tuning]

Originally Posted by D K

Hey Phil

Sounds like your project got going again!

Had my 2nd track day with supercharger yesterday...

Do you reference only pressure at the galley plug? Or temp too?
I was thinking about plumbing an accusump to the galley but ive been told the return line from the oil cooler is a better idea.
Me, personally, would like to stay as close to the mains as possible.

David

The project has been up and running for awhile now but we've been testing only. No racing until I can get 70 psi unless I turn the power down but what's the fun in that?

I have an Accusump and I'm going right at the mains as thats where a pressure drop will cause damage. The heads really don't need the high oil pressure like the crank and main bearings.

[D K]

Originally Posted by Element Tuning

I have an Accusump and I'm going right at the mains

No, if the good doctor would share how/where he plumbed the accusump into the block, this guy would be super happy

[mike the snake]

Could you use an external pump plumbed in at the sandwich plate and call it a day?

Also, what about separating the oil channels, having the external pump go to the mains and have the OEM pump cover the top end, or vice-a-versa?

Originally Posted by Element Tuning

Mike, We have actually thought of running an external oil pump as they are used on race engines. The pump needs to be much bigger than you think as there is a ton of volume needed. The OEM pump is actually very large and high volume but at the same time Subaru decided to feed the heads simultaneously increasing the volume demands.

The issue that needs to be overcome when trying to add a supplemental oil pump is how to keep it from working against the oem pump.

An external pump can replace the oem pump entirely.

[Element Tuning]

Originally Posted by D K

No, if the good doctor would share how/where he plumbed the accusump into the block, this guy would be super happy

I haven't installed the Accusump yet as I wanted to continue taking pressure at the galley plug by the A.C. and on top of the block (this is the oil galley for the main bearings). I will plumb the Accusump there with a -12AN to metric adapter.

I will most likely install an oil cooler first to see if we can at least get street oil pressures to stay in target. The Accusump will be a bandaid for the track issue of oil starvation until I'm finished testing all I can for an OEM parts oil pressure solution. Plus while I'm testing on the street its nice to still have A.C. LOL!

Thanks,
Phil Grabow

[Element Tuning]

Originally Posted by mike the snake

Could you use an external pump plumbed in at the sandwich plate and call it a day?[/QOUTE]

Yes. Doing this while retaining the air conditioning will be tough as this will require a belt driven oil pump that likely needs to be clogged off the crank pulley. Installation will be much easier than a 3 stage dry sump (2 scavenge and 1 pressure stage) however as it's all done externally. It would be no more difficult than adding an oil cooler and pulling the AC pump.

Also, what about separating the oil channels, having the external pump go to the mains and have the OEM pump cover the top end, or vice-a-versa?

It's easier to block the internal feed to the mains and supply oil via the external galley plug. Really though why bother if you will have to bolt an external pump on anyway.

This is where we stand right now as for Element Tuning we need to discover issues and then come up with staged solutions for our engine and Hydra customers. I have a couple more tricks up my sleeve that I need to test but I do think a good air to oil intercooler is going to be a must for turbocharged setups in the 400+ hp range. The cooler oil temps will overcome the pressure drop from the added restrictions.

If my "trick" doesn't work then I do believe an external oil pump along with the oil cooler would be the next stage. Track day boosted people could add an Accusump and some sort of large drain back air/oil separator.

Racers on built motors, turbocharged, slicks, and downforce like us will just need to go to a 3 stage dry sump which is a $5k investment. I'm hoping I can figure something out so we can get away with a 2 Stage like we do with our STi so a dry sump is $2k less.

[cdrazic93]

Originally Posted by Element Tuning

I have a couple more tricks up my sleeve that I need to test, but I do think a good air to oil intercooler is going to be a must for turbocharged setups in the 400+ hp range. The cooler oil temps will overcome the pressure drop from the added restrictions.

If my "trick" doesn't work then I do believe an external oil pump along with the oil cooler would be the next stage.

did your trick work?

[Element Tuning]

Originally Posted by cdrazic93

did your trick work?

Unfortunately this "trick" is not a quickie so I haven't had time to try it as it requires the removal of my turbo kit, header, and the timing cover. I've been tuning the variable cam timing with the Hydra EMS in open loop with the 14mm pump and cover so this can be an option for some people. I'm hoping I can add a cooler, an Accusump, molasses for oil, and pray it's readable at modest power for either GTA or the Ultimate Track Car Challenge.

I'm also moving forward with plans for an external oil pump.

[cdrazic93]

Originally Posted by Element Tuning

I've been tuning the variable cam timing with the Hydra EMS in open loop with the 14mm pump and cover so this can be an option for some people. I'm also moving forward with plans for an external oil pump.

Why do I get the feeling that an external oil pump would cost less than the Hydra EMS and supporting 14mm pump option...

[Element Tuning]

Originally Posted by cdrazic93

Why do I get the feeling that an external oil pump would cost less than the Hydra EMS and supporting 14mm pump option...

This14mm WRX oil pump really isn't a solution but it was worth a try. It would have been if it solved the oil pressure issue but it really didn't, it only helped the oil pressure but it still fell short. While adding an oil cooler to this would probably satisfy a street car with a built motor and boost, it still won't be enough for a track car. If the timing cover had the same sensor locations, I do think it would have been an option for many.

I'll be going back to the original timing cover, make some upgrades, try my "trick", and if that falls short, and external oil pump it is. The downside is that it will be expensive as it will require a geared belt and pullies, a new crank pulley, cnc'ed mount, deleting the air conditioning, oil sandwich adapter, AN fittings, and more. Still for probably around $1800 (I'm estimating) it's better than spinning a bearing in your newly built motor. Later down the road it could be upgraded to a dry sump also.

[kiichiro]

Fair to say the fa20 in wrx is more track ready out of the box huh?

[EAGLE5]

http://www.slwautomotive.com/products.php

Scroll down to the DC oil pump. 6bar (87psi) max and 125c max will, with an oil cooler before the pump, possibly give you what you want.