Old pic with lots of red dust on the car, from when I was fitting the bigger intercooler, removing air con, and all the unnecessary stuff getting it ready for the bigger turbo kit, which it incorporates a sightly bigger turbo than yours on the compressor side of things (6868). Not the best pic but you can get the idea.










Marios

 

I've been noticing lately, now that external temps are getting higher, that my oil pressure at idle is lower than normal based on how I have the alarm set. My dummy light has never kicked on, but the car will dip to below 5psi on the gauge for a split second before rebounding when I come to a complete stop or push in the clutch when slowing down. This was partially the reason I added the oil cooler as the increased temps lower the oil viscosity and subsequently the oil pressure. The other thing I saw was about a 10psi drop in oil pressure during WOT 36psi runs.

Regarding the oil pressure drop at high boost, the car runs a consistent 80psi of oil pressure if I rev the car to 7K rpm, but under low load or low boost of ~24psi. However, when I run the car at high boost of 36psi I saw about a 10psi dip prior to the oil cooler installation. Now that I installed the oil cooler I see about a 2-3psi dip in oil pressure at 36psi. From all of the forum reading this dip is caused by several things, I removed the Kiggly HLA, I don't have the pan baffled for high G's, and I return the TurboSmart 40psi oil restrictor to the front valve cover port. As best I can tell the real issue is just the G's when accelerating in 2-3 gear that are probably just starving the pump.

Regarding the oil pressure at idle, what I read was that when you add vacuum to the block it will actually lower your oil pressure. I did a test today and sure enough when seeing 5" vacuum it drops the oil pressure by 4-5psi on average. I have attached a video below so you can see what I mean. If you watch the boost gauge that is the vacuum reading on the can and the middle gauge is the oil pressure.

 

That is a concern. 5 psi is low, What is the idle speed when that happens?
Are you running 15-50w or a 20-50w oil?
A baffled pan is a great idea. The Racefab pan may be overkill but it won't leak and is cheaper then a rebuild .

If the turbo isn't upset about high oil pressure I would take off the TS oil regulator. More oil will go every where else.
The HLA is a good thing to have IMO.
If the bearings are going it could also lower oil pressure but that would show up quickly.

 

I have no reason to believe there is a motor issue and you can see from the video the car idles in the 15psi range even though I lose ~5psi due to crank case vacuum, but goes to ~20psi when crank case vacuum is removed. Even if I am beating on the motor and come to a stop, I see about 10psi of oil pressure using VR1 20-50 Race non synthetic with 5" crank case vacuum . I tested the factory oil pressure switch to verify continuity when the car was off since it is a NC switch. I then grounded the wire and started the car and the oil light kicks on so I know the circuitry and switch are operational, which should kick on in the 5psi range. I have not once seen the factory oil light come on so I have no reason to believe it is associated with a motor issue. I think the RPM's sometimes drop to 700-800rpm when my 5psi warning alarm kicks on, but this assumes the gauge is accurate. In almost all posts I have seen where this happens the factory oil pressure light is also flickering, which is not the case for me.

I removed the HLA after discussing with Curt because the rockers mushroomed the valve tips when I tore down the 2L, which we assumed was because of the aggressive ramp rates of the R2 cams. We opted to use the factory HLA to allow for more pressure to the lifters in hopes it would address the issue. I have the HLA somewhere, but after 30min of looking in my hiding spots I couldn't find it. I suppose I could cap the oil return from the TurboSmart port to see if it affects the oil pressure as this would be a 5min test.

I was mostly posting to show the effects that vacuum has on the oil pressure at idle and not that I had an engine concern.

 

I watched this today and the pressure dip is not necessarily associated with an RPM dip. If the pump drops from, let's say, 3K RPM to 1K RPM with no dip below 1K RPM it still has a momentary pressure drop and then instantly recovers. However, this phenomena does not always occur. I'm going to pull of the intake manifold PCV line so I don't have vacuum on the block and see what happens since I am losing 4-5psi of oil pressure due to crank case vacuum.

I did a 3rd gear pull today at 36psi and now that I have the oil cooler I don't really sea more than 2-3psi of dip. See the attached video and you can tell when I go into boost by watching my fuel pressure gauge on the left and oil gauge in the center.

 

I was on throwing ideas out there for you and others to digest. Your old setup went rounds for awhile and you are comfortable running all the boost on pump fuel.


Has far as the valve tips getting musroomed,Aggressive cams are harder on components. Your old engine had 90K miles IIRC so that seems well over the service interval of an engine making 150-200 a hole+

 

I greatly appreciate your input so thanks! No need to test the TurboSmart as it only bypasses pressure above 40psi so won't affect idle. The HLA is something I want to try just to understand what affect, if any, it has on idle pressure. I'm pretty much convinced the oil pressure discrepancy is associated with crank case pressure since it wasn't noticed until after this mod. I may need to add some type of pressure relief to the can to restrict vacuum to 2" or so.

Ordered one from Amazon for $10 so it will be here tomorrow.

 

I did not comment on your vacuum pump setup as I did not want to create any concerns and/or discourage you from doing something that seemed important to you, going down the route of building a system as such and observe its effects. I have seen similar systems in the past, and there are oem applications that actually use a vacuum pump system similar to this. This I have seen on buses and heavy duty tracks.


On our motors, a vacuum pump system is not necessary, and to be honest I expected this sort of ill-effects to happen. Drawing too much vacuum from block/crank case, will always have an ill-effect on oil pressure. The relief valve on the can will definitely help reduce vacuum. Whether that will help enough to resolve the issue effectively, remains to be seen, but I do believe it will do the trick.

Although not necessary as I said, it is a credit to you for building this, and with a couple of corrections it should not give you any more problems.


Putting trap doors in the oil pan at the right places, should also help, the same goes for the HLA, as did the bigger oil cooler addition by adding extra quantity of oil. I have done these mods to my Evo 8 also.


Here is something in regards to the difference in pump gasoline, between european and us fuel, to whoever it may concern.




Precise boost is at 2.6886 bar or 38.994 psi. This run is on 98 oct RON, which is on paper, but it seems not in applied action, the equivalent to your 93 AKI.


My turbo setup incorporates a 67.6mm comp. inducer turbo with a 68,4mm exducer, it is a custom turbo. The aero blade design on both wheels is the same as the new 9568 Xona Rotor turbo, with the only difference being, instead of using the High/Low 5 pair blade pattern, I chose to have it with 10 even blades. It is a 2.0L, high comp setup.



Going by your result difference between VD, and actual Dynojet, my setup on the specific Dynojet dyno you measured yours , should be on the 885 whp mark. The car is now on pump 100 oct RON high performance fuel with more timing/ boost.





Marios

 

I appreciate the feedback and anyone is welcome to comment as they see fit. The new PCV setup definitely has a positive affect on oil consumption from what I can tell, but not sure it needs to be 5" so going to bump it down to 2" once the vacuum relief valve arrives tomorrow. I mostly just do these things because I can fab my own stuff in the garage and I enjoy tinkering.

I'm going to do a search for the HLA this weekend and if I can find it I will try to determine the difference in idle pressure with an without. As far as the oil pan goes, unless I decide to throw on a new oil pump in the future I am not interested in modifying the oil pan because the pressure drop at WOT is minimal. I think my next area of focus is to properly shroud the oil cooler since it is angled. Thinking about creating a foam mold between the OEM duct and oil cooler face and then fiberglass over that and the OEM plastic duct. This is my plan, as of now, for this weekend.

Your dyno results are very impressive, but why does it have so much lag?

 

-My own experience lets me know that if you run the right orifices of the right size at the right places, along with the oem suction system through the intake tube and PCV, is enough for getting rid of excessive crankcase pressure caused by increased cylinder pressures. Producing too much vacuum is not a good thing. To give you an idea of the situation, on my setup I do not even run the suction part of the system, just the right orifices at the right places, no catch can either, no excessive blow by, and very, very little oil consumption when I run the car hard for a constant amount of time, mainly due to the way I have built the engine, on looser clearances. But as I said , if you like doing it, why not, and it is a credit to you. I know how that works as I do all the stuff on the car myself.


-The HLA, will not make a big difference, but it helps, of course getting the vacuum to lower down, will most possibly eliminate the oil pressure issue.


-The air duct is a must, I run a carbon one integrated into the bumper. Oil cooler gets all the fresh air it can get. Yeah you can use the oem one as a mold, no need for foam, just carbon or fiberglass sheet and resin. You can also modify the oem duct to make the mold that suits you better.


-There is no actual lag, the boost threshold is quite low for the size of the turbocharger, starts making boost at 2.7-8K rpm depending on road surface angle. I just created a very progressive boost curve, in order to keep torque down a bit, and make it more gradual, so as the stress on the gearbox and diffs is not on the destructive side of things, although I have rebuilt the gearbox on my own clearances along with heat-treating the gears and a couple of other changes it still is a 6-speed syncromesh oem gearbox and it's been 15 years since I opened it up. Also the cams I use are on the most aggressive side of things, and my dialing combo favors more higher rpm power. This boost curve also serves my driving style, the intended usage of the setup and the way and amount of time the engine spends its revving life into. Setup revs to 9600 rpm.


-As I said, it is really nice to see well made builds, and this is one of those well made ones. It is also nice to be able for one to converse in a civilized and accepted manner with someone, expressing his own experiences and views on a matter, whether these are against and opposite to, or not.


I'd also like to thank you for the kind words.






Marios

 

I you can provide any additional details and/or pics that would be great. I have a few other thoughts as well on this, but need to hook up my vacuum gauge on the turbo inlet to see if they will work.

Will update in another post, but lowering to 2" doesn't resolve the issue.

Just going to attach the foam that I purchased to the end of the OEM plastic duct and then shape it to fit the front of the oil cooler. I can then bondo it smooth and glass over with epoxy resin and vacuum bag. I will basically just be extending the OEM duct to match the front of the new oil cooler.

I try to ignore the trouble makers and like to hear other people's thoughts. Can you share more details and pics of your setup?

 

So the vacuum relieve valve showed up in one day from Amazon and was only $10. I ended up taping the ID of the -10AN male fitting and put a -10AN cover over the threads. Works like a champ and I see a constant 1" of vacuum when driving and a constant 2" at idle. I went out and beat on the car pretty hard and came back to let it idle and it is a hot day in Charlotte. Car idles around 10psi fully heat soaked so less than I want so I have ordered a new OEM oil thermostat, OEM oil pressure switch, and OEM oil pump front cover. I also like RSMike's external oil pressure regulator so I might add that and modify the pan for its return. Might as well baffle the oil pan while I am at it, but don't think I will add any capacity since I don't race the car. Ugh, it never ends!

 

When people ask me "why is your car so stock?", I'm gonna quote you

 

Best route of action.






Marios

 

They are self inflicted wounds!