SPEED_NYC

Brian, the FD press regulator is not the same as the racing beat one. the racing beat regulator is a lil higher pressure than the FD one. racing beat lists it as 130 psi on thier site, which is a misprint, its actually 115 psi. as far as using FD regulators on FC motors, it does work and is a good upgrade from the stock FC regulator. most FD regulators that we replace with racing beat units get donated to FC turbo motor rebuilds.

BDC

Very cool. This is what I suspected. What I'm not sure about is whether or not the overpressure control valve on the front cover needs to be shimmed with a couple of flat washers or not for using this FD regulator on an FD. This is something I'm planning on doing to my motor when I tear it down but am unsure of the facts. A friend of mine said they changed his buddy's S5 13BT regulator from the FC one to an FD one and _did not_ shim the spring on the front cover's control valve. They say it runs perfectly fine and hits the targetted oil pressure intended. Is this true or is he feeding me full of crap?



B

mazdaspeed7

In my experience, this is a line of crap. The front regulator starts acting at a slightly higher oil pressure than the rear regulator. It will need to be shimmed, or you wont see full oil pressure until high rpm. While you may still reach full oil pressure at some point, its relying on the front regulator being maxed out before the pressure can climb above what the front rgulator is set at.



In the last motor I build(S5 6 port), I used a TII oil pump, FD rear regulator, shimmed the front regulator to ~110 psi, using type 2 main bearings and grooved stat gears, and I modified the oil jets. I enlarged the hole, but left the ball and spring in. I see 60 PSI at idle, and 100-110 by 2500 rpm. One thing I have noticed though, is my engine takes longer to warm up, especially when its cold outside. With my oil pressure that high, the ball and spring never shut off the oil flow through the jets, resulting in the same effect as the weber jets.

BDC

How many washers did you shim the front pressure control valve with?



B

Cheers!

five M7 metric washer

BDC

We talkin' about the same thing here, Cheers? Five M7 flat washers is used to disable the front thermo bypass pellet. Are you saying use the same for the front oil pressure control valve? It looks smaller, like M5's.



B

tampaFD

mazdaspeed you left the ball and spring in? wouldn't high press close the ball to the jets?

Cheers!

oh *****... sorry it's the crack pipe... it was just passed my way and i took a long pull...

Mazderati

Maybe I am thinking of something else but I thought the ball and spring combination was operated in relation to oil temperature with the ball and spring system being put in place to reduce emissions by speeding warm-up time.



At any rate, this would be a "must" for a rotary engine in my book, as it eliminates what could be a trouble spot.

mazdaspeed7

It doesnt eliminate a trouble spot. Nothing in a car eliminates a trouble spot. All youre doing is shifting compromises. The ball and spring cuts off the oil flow to the jets at low oil pressure, like at idle, to preserve oil flow, so it goes where it really counts: the engine bearings. As the oil pressure increases, it moves the ball away from the orifice in the ecc shaft, allowing oil to pass around the ball, and through the jet, and be sprayed into the rotors to cool them.



An engines thermal efficiency goes up as the temp goes up. Less energy is being lost in the form of heat being drawn from the chamber. But EVERYTHING in a car is a compromise, including thermal efficiency. I bring this up, because it has to do with the oil jets. The more they are workign at idle and cruise, the more gas your car will use to make the same power, since more energy will be lost into keeping the engine up to temp.



In effect, at idle and cruise, youre overcooling the oil system. While the oil thermostat keeps the temps adequately high by bypassing the oil cooler, you are not operating within the best efficiency zone. The design of the oil jets in stock form, including the ball and spring takes that into account. And it still flows enough to adequately cool the rotors when you need the cooling, such as high rpm and/or high power.



Now, the oil jets were designed around stock power levels, and while Im sure there was some cushion designed into it, to err on the side of safety(and reliability), it will not be adequate past a certain hp level. But the oil jets are completely dependent on oil pressure. When you increase the oil pressure, more oil will be flowing through the jets. Most people who increase power more than just bolt-ons provide already run higher oil pressure because its better for the bearings.



The only time I would deem the weber jets necessary would be a pure racing motor. It will never see idle except to warm up, and make it around the pits, etc. The majority of the motors life will be in the high rpm range, and the nature of racing shifts the compromises in a considerably different way than a street perfomance engine.