annuerysm

I'm in the process of rebuilding a S4 13b and I want to upgrade the Oil Pressure Regulator, I going to get either the mazdatrix 85 PSI one, but is it possible to use a FD 120 PSI regulator? Thanks.

j9fd3s

yes but it will give you 120psi



mike

BigTurbo74

why would you want to "upgrade?" better flow? would you have to upgrade oil seals?

toddp31

I have heard of people doing it, the stock seals should be alright

vosko

higher pressure is better make sure everything else can take it or you will get leaks

BDC

You sure, Mike? It's just a bolt-on? I could care less about the 120psi; besides, I know how to drop that a bit.



B

Cheers!

i thought the FD oil pres regulator was set at 110 psi

j9fd3s

a friend of mine did it in 92-93 with an old school 4 port 13b built from new parts. he said it would peg the 130psi guage. i dunno maybe you need the front regulator too?



mike

n.taluckder

i was thinking about doing the same thing until i read this article http://fc3spro.com/TECH/MODS/ENGINE/OIL/opr.htm

Lynn E. Hanover

The 85 pound piece is fine for anything short of all out road racing.



Adding more than that just makes the pump wear faster. Plus the pump parts are powdered metal.

A magical system for making parts look strong that aren't.



Oil pressure is raised to shorten time in the bearing and thus reduce bearing temperatures.

This assumes that cooler oil is available from your much larger and more effective oil coolers.



That grey looking stuff on bearings is very soft and has a low melting temperature, so cooling is important.



The temperature of the oil comes from a number of sources. Oil is sheared as it goes through the spinning bearing. This adds heat. The oil pump adds heat as it raises the pressure of the oil. So, more pressure = more heat from the pump. Oil is used in the rotary to remove heat from the rotor. Higer performance = more fuel burned = more rotor temps = more oil temperature. Lower oil temps = lower rotor face temps = more power. So, lower oil temps means more power or better mileage. So first you need bigger coolers. In fact bigger coolers adds power, and is good enough until you are just screaming the engine every day.



High oil temps mean more oil foaming. Air is an insulator, so foaming means the oil can absorb less heat, and that the coolers become less effective at removing it. All bad mojo.



Synthetics generally foam less, have higher film strength, and if overheated maintain their "oil like" qualities rather than turning into a smelly black mess. If the OMP is still in use then rater than a synthetic I would use a straight weight name brand racing oil in 30 or 40 weight. The thinking here is that without the long string polymers of the multi-grade there is less plastic in the oil to gum up seals and add carbon to the rotors. Oils without the multi grade plastic burns cleaner. Racing oils generally have high film strength and anti faoming additives, to help oil cooling.



We raced for years on 75 to 80 PSI by altering the early relieve valve. It can be disassembled and washers added to adjust pressure. Use the shop air supply to test the cracking pressure.



Once the engines got to $14,000 a copy we went to a dry sump system and ran 100 PSI. Plenty for up to 9,600 RPM.



Why anyone would need over 100 PSI escapes me. Use a K&N filter and screw it on tight. They have 500 pound burst pressure.



Front and rear seals are pressurized by crank case pressure (blowby). Added oil flow produces no detectable pressure increase on the seals.



There is much more.



Lynn E. Hanover



Picture is a three rotor turbo used as an airplane engine.