Just watched back a few laps of my last incar. It does sit pretty consistently around 50psi, probably as high as 60psi off throttle and downshifting, the lowest is probably around 45psi. Oil temp is around 110 and water temp around 95.
So your temps are similar to mine at the moment, I'm not sure about yours but mine has plenty of room for improvement with ducting etc. as there's basically nothing there now. Where are you pulling temp from? Mine comes from the port on the filter tree which with a full flow system I'm pretty sure is after the cooler so my sump temp is probably a little over 100. In his build thread black beast reported sub 90 at the sump when the engine was working hard with his super heavy duty full flow system. Also what weight oil do you run? I've usually run 50+ which peaked at 70-80psi hot so if you're using a 30 that would probably explain some of the difference. I've got 15w-40 in now but haven't done much work with it yet.
I'm running Castrol Edge 5W40 SN. Oil pressure is from the stock location, with a relocated sender. Oil temp is from the oil filter tree.
I wonder what the pressure drop is from the filter to the passenger side turbo oil feed, I used to have my sensor in the cooler lines but with the recent work ditched the stock sensor and put my good one over there so if I go back to a 50 weight I might be able to tell, don't think I've got any proper records though so might not be very good data.
This thread amounted to much more than I thought it would, this is great. I would love to see that oiling diagram in the FSM. So if the stock oil cooler is fed oil only as a bypass valve over 50 PSI, it doesn't seem like using that route would be the best way to maximise your cooling capability since you'll only ever get any cooling at all when over 50 PSI (or is it only needed above that pressure anyway?). Why not fit up a thermostatic sandwich plate and run the cooler full flow off of that, and then plumb a straight hose linking the original oil cooler feed/return? That way when the pressure gets too high the engine can still bypass oil back down to the sump, and all oil that was going to the motor stock still goes to the motor, but is also first cooled if necessary (as regulated by the thermostat). Does that follow? Depends a lot on the bypass rate of the thermostat though. What's the best place to measure oil temperature from?
Do you mean run the oil flow from the pump, to the cooler, to the filter, then to the engine, and have the factory pressure bypass feed straight back into the sump? Provided U still had a restrictor between the tree and the sump this would probably work well.
Now that you mention it that is how the Z1 kit appears to be set-up https://conceptzperformance.com/Cart/description.php?II=1231 You can see the restrictor bulge in the bypass line too. The diagrams are on page four of this http://stadzport.com/FSM/LC_Lubrication_Cooling.pdf there are specs for pressures and testing procedures for a few bits on the following pages.
Also, you're right anti that full flow is inherently more efficient than the bypass as you're supplying more hot oil to the element keeping it's temp higher and a greater temperature difference means faster energy transfer, the same applies to oil in the block, the more oil you flow through the engine the more it assists cooling and oil is not an insignificant component of engine cooling. The question is will you need it though, me and Shane are talking about at least 15 minutes of proper flat out acceleration/braking cycles so giving it a hit through the mountains now and then isn't going to need anywhere near as much cooling. The other benefit of full flow is it keeps cooling once you're at idle or low revs, when the water cooling system is up to par it doesn't seem like much additional oil cooling is necessary especially when your turbos are ball bearing rather than journal. I did a couple hours of highway driving the other day and when I pulled up the sump temp was still sub 80 (Nismo water thermostat) with no oil cooler or bypass hose fitted but if you are doing hard circuit work then cool down laps will be more effective with full flow as it keeps working even under 3krpm. For checking temps you use sump temp mainly to check the peak temperature of the oil so you know you're not cooking it, from memory around 140C is when most oils start to show breakdown. Checking oil temp after the cooler lets you know what temperature is being fed to the bearings so you know that it's around the correct viscosity, a 30 weight at 140C may the viscosity of a 20 or less at normal temps. The temperature of oil being fed into the engine also determines how much you can cool the pistons, bearings, cams and other parts that don't have water galleys, cooler pistons means more boost but I'm not really familiar with the operating temps of the rest.
Mad. I'll do that then. I forgot to mention the restrictor, that would be in the bypass line yes Shane.
If a thermostatted system resulted in low oil temps, then it was not working correctly or the sump was dissipating enough heat to begin with and the thermostat was actually doing its job. Did those temps result AFTER the thermostat was fitted? The questions you need to ask BEFORE adding in funky accessory system is: Were you having oil temp issues to begin with? I think its fair to say that the vast majority of us DONT know and the rest havent had an issue unless circuit racing and even then, most people start panicking when they see temps up near 100Deg.C!. In fact, THAT is precisely where your oil temp needs to be and Ill be willing to bet that very few of us have ever seen oil temps that high. The only time I saw oil temps above 95Deg.C was on a very rare 40+ deg.C day and stuck in traffic with aircon running and oil temp made it to 110Deg.C which is perfectly acceptable. Sometimes adding all this funky clobber is basically doing modifications for modifications sake and ultimately results in at best a pretty looking WOFTAM. With regards to oil component routing, it is far better to filter hot oil (pre-cooler). The hotter (runnier) the oil, the more oil will actually be passed thru the filter medium rather than be bypassed and returned to the sump. E
No disagreement with most of that, I was having temperature problems before getting heat-soak on the highway but that was with a coolant system that wasn't very healthy, I replaced/upgraded almost everything in the engine bay at the same time so went from sub-standard to overkill in one motion, I do play on the circuit when I can and it definitely does it's job there. I'm pretty sure the thermostat is performing as designed its just that the bypass isn't free-flowing enough that flow through the cooler is completely stopped and with a big cooler it drops the temp pretty effectively so even if only 20% of the oil flows through the cooler there's a big on sump temperature. Filtering hot oil makes sense although unfortunately due to the way things are assembled sandwich plates always run to the cooler before the filter, a filter relocation kit would allow you to set up a system than ran through the filter first.
15mins pfft Prod Sports are 1 hour races :br: Yep, I'm thinking if I make any modification to the oil flow circuit this will be it. Hadn't though of simply routing the pressure bypass straight back into the sump. This was a very good discussion, well done lads :zlove:
The other possible issue with running a full flow oil cooler setup is the time it takes to build pressure on initial startup. Stock the engine (and turbos) see pressure almost immediately. If full flow the oil needs to pass to the filter, cooler and then back to the engine (nearly 2 metres) before you see any pressure in the engine. Does anyone think this would be an issue? Maybe fitting an anti drain back valve somewhere in the system. Obviously there will be oil still in the lines and cooler so maybe not a big deal? I remember on my first racecar I used to always crank the engine a dozen times before starting to get oil to the turbo, but it was mounted high so I guess it took a bit to get oil up to it.
No, because the thermostat in the sandwich plate is closed. The oil doesn't "full flow" to the oil cooler 'til it's up to temp.
You can't not. It's critical. If not, all oil will run through the cooler regardless of whether it needs cooling or not and you'll over cool.
Has your new Z set up done an hour long session yet though? As I mentioned earlier the oil cooler and its lines remain full while the engine is off, only increase the chances of a dry start immediately after installation or oil changes same as the rest of the engines oil galleys. If you're getting dry starts it's either a faulty drain back valve or leak-down through other oil channels. Same as the clutch and brakes, once the hydraulic line is bled it should stay full.
So do you wait before driving your car or revving beyond idle until your oil temp is 100degC? Everytime? Have you timed how long driving your car until the oil reaches these temps. Is your engine going to fall apart if you don't? And for my application I don't think there'll be any problems with the oil running too cool. If you're fitting a cooler that's going to result in your oil running too cool, why are you over engineering your oiling system?
