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Hello everyone,
I have a somewhat unusual "problem" which doesn't seem serious at first glance, but is causing me a bit of a headache. Perhaps you can give me a few ideas to put my mind at ease or at least explain it.
I drive an Audi S2 Coupe with a (formerly) 3B engine. Over the years, it has become a 2.5L RS2++ Step with 435 hp with a TTH450 charger on the RS2 manifold. This winter, I converted to a G30-770 + tubular manifold. Since everything was accessible on the side anyway, I replaced the oil thermostat with the 83°C Mahle, which is actually intended for Porsche. I wanted to add a little more thermal relief. I still drive with the original oil cooler, but I only drive the vehicle on country roads and can take my foot off the accelerator at any time if the oil temperature gets too high.
Now to the "problem": since the conversion, I have almost 1 bar MORE oil pressure. In the old setup, I already helped the oil pressure along with a 4 mm spacer on the pressure regulator in the pump to reach 2 bar at idle with 10W60. Now I've already gone back to 3 mm and still have 3 bar at idle with water at 90°C and oil at the "magic" mark on the gauge. Now, you're usually happy about decent oil pressure, but not when you don't know where it's coming from.
I switched from a journal bearing turbo without a restrictor to a ball bearing turbo with a restrictor. But does that actually increase the pressure in the rest of the system? Could it have something to do with the thermostat? I'd appreciate any ideas.
Does anyone have a schematic diagram of the oil distribution in the 20V turbo?
Of course, the next step will be to remove the 3 mm spacer and see if that helps, but that's really just tinkering with the symptom.
Thanks and best regards
I have a somewhat unusual "problem" which doesn't seem serious at first glance, but is causing me a bit of a headache. Perhaps you can give me a few ideas to put my mind at ease or at least explain it.
I drive an Audi S2 Coupe with a (formerly) 3B engine. Over the years, it has become a 2.5L RS2++ Step with 435 hp with a TTH450 charger on the RS2 manifold. This winter, I converted to a G30-770 + tubular manifold. Since everything was accessible on the side anyway, I replaced the oil thermostat with the 83°C Mahle, which is actually intended for Porsche. I wanted to add a little more thermal relief. I still drive with the original oil cooler, but I only drive the vehicle on country roads and can take my foot off the accelerator at any time if the oil temperature gets too high.
Now to the "problem": since the conversion, I have almost 1 bar MORE oil pressure. In the old setup, I already helped the oil pressure along with a 4 mm spacer on the pressure regulator in the pump to reach 2 bar at idle with 10W60. Now I've already gone back to 3 mm and still have 3 bar at idle with water at 90°C and oil at the "magic" mark on the gauge. Now, you're usually happy about decent oil pressure, but not when you don't know where it's coming from.
I switched from a journal bearing turbo without a restrictor to a ball bearing turbo with a restrictor. But does that actually increase the pressure in the rest of the system? Could it have something to do with the thermostat? I'd appreciate any ideas.
Does anyone have a schematic diagram of the oil distribution in the 20V turbo?
Of course, the next step will be to remove the 3 mm spacer and see if that helps, but that's really just tinkering with the symptom.
Thanks and best regards