FA20 Engine Oiling, Bearings, and Starvation

[Element Tuning]

Originally Posted by serialk11r

That FA20 pump gear looks super weird! The little "holes" would seem to allow a little leakage of oil back and effectively lower the displacement by a tiny bit. It might be that the discharge port is shaped kind of weird and at high rpm it would generate more pressure, but that makes no sense, if anything you want higher pump displacement per revolution at lower rpm to generate the necessary pressure quickly and not the other way around. That's how all the variable displacement pumps work these days, they open an internal valve to reduce the flow at high rpm without incurring the losses of the traditional relief valve so that you can keep the pressure at say 60psi as if the pump were spinning slower.

Maybe it's just a way for Subaru to make a lower flow oil pump from an existing design. The turbo FA20 probably needs more than just 14mm/12mm =1.166 times more flow than the NA engine.

It's for low RPM efficiency and high rpm flow. So the focus isn't to have high pressure at low RPM.

[serialk11r]

Originally Posted by Element Tuning

It's for low RPM efficiency and high rpm flow. So the focus isn't to have high pressure at low RPM.

I'm not well versed on oil pressure and flow needs of an engine from a bearing protection standpoint but on modern engines I thought you want significant oil pressure at low speed to power your chain tensioners, cam phasers, and hydraulic lifters if applicable. The gas cycle efficiency benefits of VVT are partially offset by the need for a bigger oil pump. It seems extremely weird to decrease oil pressure at low rpm when it's critical for making the VVT work quickly, which does a lot more for fuel economy than lowering oil pressure.

That's why I'm thinking the design might just be a significantly reduced displacement pump without any atypical rpm dependent behavior. A thicker, bigger pump gear pumping the same amount of oil would have less load and probably be more reliable. My guess is that the inner teeth start to seal against the outer teeth at the bottom of the indent instead of near the top of the indent like usual thus cutting the displacement by a significant amount. Does 1/2 the oil flow of the WRX pump sound plausible, empirically?

[Element Tuning]

Originally Posted by P86RAVES

Could you expound on that a little? This perspective is interesting.

I've resolved myself to never modify this car so long as I own it. Until I owned it I was in love with the car, but after driving it about and window planning a modification route.... I kinda despise it because it's not at all what I was hoping it would be.

Do you think within the next 5 years the money:performance will improve, or do you think shops will start treating it like an RX-8?

It's about the cost for performance for a given platform. If this was a factory $75k car then the costs wouldn't be out of line but for a $25k car the cost for performance is high. This shrinks the market down is all.

It's a good performer at 300 whp but as you push past that it gets exponentially more expensive. I think in time more will actually spend big bucks than they are now since the new car, warranty.....etc is still in the mindset of the average owner.

It's hard for me to be happy at this power level as I'm used to racing 500-700 whp cars. This chassis is capable and that's what's frustrating. It's getting to the point where I don't want to be the one to figure it all out. I've done a full plug and play stand-alone, the engine (still moving forward), the braking system, and now I don't want to be involved with the transmission. I just want to write a reasonable check to someone else. LOL!

[Luckrider]

Originally Posted by Element Tuning

It's about the cost for performance for a given platform. If this was a factory $75k car then the costs wouldn't be out of line but for a $25k car the cost for performance is high. This shrinks the market down is all.

It's a good performer at 300 whp but as you push past that it gets exponentially more expensive. I think in time more will actually spend big bucks than they are now since the new car, warranty.....etc is still in the mindset of the average owner.

It's hard for me to be happy at this power level as I'm used to racing 500-700 whp cars. This chassis is capable and that's what's frustrating. It's getting to the point where I don't want to be the one to figure it all out. I've done a full plug and play stand-alone, the engine (still moving forward), the braking system, and now I don't want to be involved with the transmission. I just want to write a reasonable check to someone else. LOL!

In that vain, is it worth doing the full blown V160 supra swap?

[P86RAVES]

Originally Posted by Element Tuning

It's about the cost for performance for a given platform. If this was a factory $75k car then the costs wouldn't be out of line but for a $25k car the cost for performance is high. This shrinks the market down is all.

It's a good performer at 300 whp but as you push past that it gets exponentially more expensive. I think in time more will actually spend big bucks than they are now since the new car, warranty.....etc is still in the mindset of the average owner.

It's hard for me to be happy at this power level as I'm used to racing 500-700 whp cars. This chassis is capable and that's what's frustrating. It's getting to the point where I don't want to be the one to figure it all out. I've done a full plug and play stand-alone, the engine (still moving forward), the braking system, and now I don't want to be involved with the transmission. I just want to write a reasonable check to someone else. LOL!

I get where you're coming from and thank you for taking the time to reply.

[Andreas83]

Found some info on the reimax pump gears on a uk forum.
Theoretically they should flow more oil based on the measurements he has done.
http://www.gt86.org.uk/forums/topic/...details/page-2

I have a set on order.

[The Racers Line]

Originally Posted by Element Tuning

No it's not that simple as the front and rear rotor diameters along with piston surface areas had to be reconfigured to give us the balance we needed and that the OEM system could deal with. OEM bias is off the chart wrong for racing.

Is it something you guys will be offering to the public?

[PowderfaceTr.]

How are you guys not dry sump?

[cdrazic93]

Originally Posted by PowderfaceTr.

How are you guys not dry sump?

They will eventually, theyre just prototyping springboard ideas for those who want a oily track car without the price of a dry sump.

[Element Tuning]

Don't forget I tested a 14mm pump with the traditional tooth profile and it didn't help enough (this was with the factory oiling setup and not our engine mods). I suspect that gear will just ramp pressure faster is all.

[Element Tuning]

Originally Posted by Neal@EQtuning

Is it something you guys will be offering to the public?

Yes, this is a product the community will be able to purchase and the manufacturer is building stock after I gave it the

[Element Tuning]

Originally Posted by PowderfaceTr.

How are you guys not dry sump?

We will it's just the first attempt didn't go as planned so back to the drawing board. I have new parts on the way to me to test but I'll need to fabricate so new items. Fingers crossed we get the pressure we all need for high power!

[Darryljr11]

Someone should make a gearset like this lol
http://www.vividracing.com/catalog/-...37832010-RRS50

http://www.vividracing.com/catalog/-...45232270-RRS50

[D K]

A stronger gearset isnt going to help a lot.
There is an inherent design limitation with our stock gearbox.

Straight cut gears might help more since they are less susseptible to shaft flex.