Yeah, I'm doing oil 1st and going to see what happens. I have never had this issue before even with any of my OLD SCHOLL DSMS lol, but I guess we will see what the outcome is.

 

If you have a lack of oil pressure at wot that’s a large concern. Going to a thinner oil is going to lower pressure.
You may want to cut open the oil filter and check it incase there is an issue.

I would still suggest measuring oil pressure at the oil filter housing moving forward. That is where most measure it so you can compare apples to apples.

20-50 is thick oil and takes time to warm up. I realize it’s thick oil but high HP 4g63’s have run it for years with good results.

 

Yeah, just want to see all different options before I take off the oil pump! I mean here where I live it is cold and I only drive the car when there are warmer days. But again, I just want to rule one thing out at a time and hope it's only the pump if worse comes to worse. Cold start I am still getting about 80 psi and this is a used pump. At idle engine temps sitting at 180-190* and I still get 25-30psi of oil pressure.

 

Most high HP evos don't run in cold weather either.

 

yeah, this is true. Here in southern Ut the weather will be nice and warm and then its ice cold. I have always run 20w50 oil and again never no issues with oil pressure while doing WOT but here it's a lot different than SoCal! It's kind of scary cause at times driving the car and hearing a loud tick thinking maybe a spun bearing but I have already verified it's my loud *** injectors.

 

Lol that's why I got rid of my 2150s and went with id2600s. No more loud tick. But yeah 60° cold weather is so much different then 40° and colder specially with 20w50 in the car.

 

Yep, I am running FID 2200's which are the Bosch and idk I guess I never really noticed how loud they are until the other day dealing with the oil pressure issue. For now, I am going to go down to 10w30 and see what change there is if any. My oil clearances are not super crazy so 10w30 will do just fine.

 

So the title of the thread is "oil pressure drop at high rpm". Suggestions were made and Viscosity came up on startup. Your first step is going down to 10w30 for even less oil pressure at wot.

Its a performance engine ,not a prius. 5w40 would be the minimum on an 80's rally engine making good oil pressure and power. There is also 5w50 oil available.
Most of us run 20w50 and let the car warm up a bit before going out. Then another 15 minutes or so to get the drivetrain warm before making a pull. For high hp its a proven combination.

May want to keep reading the forums or call a few evo shops. You spent alot of time and money on a rebuild and 60psi of oil pressure at wot isn't going to end well. What did your last engine make for pressure with the sensor in its current location?

 

going down to a 10w30 and seeing what change there is is not going to hurt anything! I drive the car like a grandma for one and I always let my car warm up for at least 15/20 mins because the weather here changes so fast sometimes I wait longer. I have built many motors and used the 20w50 oil in a lot of builds!

The weather here gets cold so changing to a different viscosity will help me rule oil viscosity. I have oil pressure it’s not like it down it’s the teens at all times. And 10w30 or even 10w40 and my oil clearance are going to work perfect no issue. I don’t need to read more! On start up I am getting 80+ psi of oil pressure and a warm motor I’m still getting 25/30 psi. WOT and seeing 60 psi yeah it’s not the best but I don’t stay in the pull seeing the oil pressure drop like it does.

 

If the motor was set on the oil pan it could have closed down the gap between the bottom of the pan and the pickup starving the oil pump of flow.

 

No pan is good clearance for the pick up is good also. I’m thinking if oil viscosity doesn’t make a change than pump will come off inspected and install new pump and move my sensor to the OFH

 

If your idle pressure is this high when it's hot, it doesn't scream "oil pump is poked".
If you warm the car up and rev it to 6000rpm in the driveway, is it still 55-60psi?
Or is it higher?

I want to know if it's G-Force induced, or if it's low at high rpm all the time.

 

Good question, I am not to sure I haven’t done that kind of test but I will and post the results.

 

Bringing this back as I'm having almost exact same things happen and want to see if you found anything interesting! I was running 10w40 and now have 15w40 in and I get 100+psi at idle on cold startup, warm idle is between 25-30psi. When cruising it is around 65-70psi. Goes to about 85psi when I go WOT and then around 7,800rpm-9k it slowly drops into low 70s. Get back under that RPM after I let off then it is back to around 70psi. It did this before and after adding my STM oil cooler just for reference. I have pulled my last 2 filters apart and there is no metal. Also pulled the pan for kicks and all rod bearings are perfect .

Important details:
-Fresh engine build (less than 2k miles)
-Balance shaft delete (piston oil squirters still in)
- Brand new OEM oil pump (when engine was built)
- All hidden oil galley bolts sealed such as behind the engine mount
- Brand new OEM Buschur baffled oil pan (never been pushed on)
- Kiggly HLA
- GSC zero tick lifters
- AEM 150psi sensor on oil filter housing (not back of engine block)
I bought a whole new OEM gasket kit for the pump and OFH and sprayed then with copper spray to also make sure nothing was getting past the gaskets for some reason. Didn't really do anything.

It's just weird because as long as I am under 7.8k the oil pressure is great. Did you ever figure anything out on yours?

 

Do you know what your clearances are set to? If they are greater than stock and especially .0025+ 20w-50 oil is highly recommended.