What's so bad about the aux oil pump running dry? The ones I was looking at said dry operation would be fine. And on a track I'm sure oil sloshes forward a lot more than just when brakes are applied.
Like spliced into the factory return line? Of course... just find the right fitting to t into it. You can plumb the accusump into anywhere that there is pressurized oil. You can tap right into the main oil galley where the oil temp sensor is if you really want to.
Would a thinner oil help starvation at all? Considering it should be able to flow easier at temp back to the pan. That combined with a modified VAC baffle and an extra qt of oil maybe.
Can you further weld the edges of the baffle to the pan, closer towards the flat section? That would trap the some of the oil from sloshing in that direction when braking/turning and would still be able to flow back into the pan through the hole and sides.
Just thinking of other ways besides adding an accusump for others with this issue.
Can you further weld the edges of the baffle to the pan, closer towards the flat section? That would trap the some of the oil from sloshing in that direction when braking/turning and would still be able to flow back into the pan through the hole and sides.
Just thinking of other ways besides adding an accusump for others with this issue.
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Once up to temperature, the difference in oil weights is negligible. 200f oil basically has the same viscosity as water. Viscosity is important for bearing clearances as small as .001" but no so important for flowing through a 1" wide oil return passage in the cylinder head.
I'm not sure that's true. They should in theory all flow at a different rate, the thinner being faster which makes perfect logical sense right? For sake of argument I just quickly looked up redline oils:
0w20 viscosity @ 100°C/212°F, CSt - 9.1
0w30 viscosity @ 100°C/212°F, CSt - 11.7
0w40 viscosity @ 100°C/212°F, CSt - 15.4
And CSt stands for Centistokes, where water is 1.0038 @ 20°C (just googled it) for comparison. It might not make a big difference, but getting maybe an extra 0.25-0.5 qt faster to the pan might help that second of starvation where it sloshes forward too far. However I'm just throwing ideas/theories and there's no way to test it really aside from logging pressure and running the exact same track, speed, and braking conditions I suppose.
I definitely know what you're saying. I have said similar things myself. But it's just not realistic. I think you missed my point a bit. Of course "thinner" flows faster. That is what kinematic viscosity is a measurement of lol... how quickly oil flows through a tube. Not denying that.
People think of oil as being "thick" because they usually see/pour it at room temperature where the viscosity is closer to 200cSt+. At temperature, 15cSt might as well be water. 9cSt vs 15cSt isn't really going to make a lick of difference in regard to this discussion. This issue is still g-force and roll angle. whether the oil is thick or thin it's going to be returning to the front of the pan when you are braking turning etc. It's just an inherent issue with a wet sump.
Further, you can't really run a 20wt oil as it doesn't have the dynamic viscosity needed to support bearing loads. Need at least a dynamic viscosity of 3.5cP. So, you're basically saying what if you ran a 30wt vs a 40wt and quite frankly just about every LL-01 40wt oil is already on the thin side and might as well be called a 30wt.
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Fair enough, I see your point. I thought I read that 40wt oils were too thick for our (N54) tight bearing clearances anyway? I can try to find the article/thread. I recently saw one Pennzoil 0w30 oil that had a viscosity index of over 200 - which is NUTS for an off the shelf oil, it also had the Porsche C30 & VW 504/507 which has super strict requirements similar to LL01/LL04 but is a low SAPS oil. Would be fine for short drain intervals though.
There are many 40wt ll-01 oils. Like I said, they are all generally on the thinner end of the sae 40 range like 12-14cSt whereas anything up to 16.3cSt is considered a 40wt oil. Ll-01 also seems to generally be high saps oils.
Im waiting for my tuner to send a new map, as Im over boosting a bit at the moment. Therefore I still haven't been to the track yet. My workshop said they tested the baffle with water before installing the pan, and were satisfied with how it worked.
However, being a bit impatient, I plugged in the oil pressure gauge to see if I could get some results by driving on the streets today...
It just isn't doable.
This makes me appreciate how nice it is to have access to tracks, although my next test may show that I need to stop going, if the oil pressure still drops as before.
The speeds and forces you achieve, even when driving only moderately fast on a track, are just way beyond what happens on public roads. Another thing I have noticed is how the personality of my car changes between street driving and the track. On the street it feels overpowered, overly sensitive and super direct due to the suspension bearings, aluminum/poly mounts, stiff sway bars etc etc. I often find myself changing lanes just for the fun of it, because the directness feels so great. I have also become traffic averse, as the car requires concentration to drive smoothly at slow speeds on the BQ map. It just doesnt really like to go slow. And I almost never go WOT either. It makes no sense in 2nd gear with my current 265 tires, and in 3rd it becomes dangerous and super illegal very fast.
Then on the track it is like driving a totally different car. Suddenly I feel weight transfer that just wasn't there before, and a new world opens where brake temperature matters, tire temperature matters, and the car becomes loud and imposes actual strain on my body. WOT all the way up into 5th is a given on every lap, and you can feel how timing corrections, rising iats etc takes away bits of crucially needed power. All of this, in the very same car that felt totally overpowered on the streets.
No wonder top gear etc often go to closed circuits to evaluate cars.
Anyway, to get back on topic, I took note on the following oil pressures, as read by my gauge during warm up.
Cold start: 95psi
80C / 175F oil: 55psi
115C / 240F oil: 35psi
Im running 5W40 Amsoil, and the numbers may be off by some calibration factor, but I don't expect them to be offset.
However, being a bit impatient, I plugged in the oil pressure gauge to see if I could get some results by driving on the streets today...
It just isn't doable.
This makes me appreciate how nice it is to have access to tracks, although my next test may show that I need to stop going, if the oil pressure still drops as before.
The speeds and forces you achieve, even when driving only moderately fast on a track, are just way beyond what happens on public roads. Another thing I have noticed is how the personality of my car changes between street driving and the track. On the street it feels overpowered, overly sensitive and super direct due to the suspension bearings, aluminum/poly mounts, stiff sway bars etc etc. I often find myself changing lanes just for the fun of it, because the directness feels so great. I have also become traffic averse, as the car requires concentration to drive smoothly at slow speeds on the BQ map. It just doesnt really like to go slow. And I almost never go WOT either. It makes no sense in 2nd gear with my current 265 tires, and in 3rd it becomes dangerous and super illegal very fast.
Then on the track it is like driving a totally different car. Suddenly I feel weight transfer that just wasn't there before, and a new world opens where brake temperature matters, tire temperature matters, and the car becomes loud and imposes actual strain on my body. WOT all the way up into 5th is a given on every lap, and you can feel how timing corrections, rising iats etc takes away bits of crucially needed power. All of this, in the very same car that felt totally overpowered on the streets.
No wonder top gear etc often go to closed circuits to evaluate cars.
Anyway, to get back on topic, I took note on the following oil pressures, as read by my gauge during warm up.
Cold start: 95psi
80C / 175F oil: 55psi
115C / 240F oil: 35psi
Im running 5W40 Amsoil, and the numbers may be off by some calibration factor, but I don't expect them to be offset.
Finally got a chance to test the reversed pump on track, and the oil pressure still drops from 95psi to around 50-60psi when trail braking into a left hand hair pin running AD08R tires. The only change I noticed is that the oil temperature fluctuates a lot more now, as the sensor gets a bucket of cooled oil every time I brake lol
Three questions
1) Should I be concerned? When pressure dips, it is still above idle oil pressure. At least according to the analogue gauge which may have a delay.
2) Given that an accusump runs at 55-60psi, would it even help in my case?
3) Is there consensus that I should have the pan re-welded as suggested above?
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Can't really answer these questions. We are all just trying to keep our cars form blowing up lol. You need to make sure your oil pressure sensor is seeing the actual oil pressure being supplied to the main oil galley before making a decision on the Accusump. You seem to be going through hell with this car though. Just enjoy it as is for a while? Swap in new rod bearings each season as a preventative measure? No matter what you do, raced engines don't live forever.
So I have decided to do the following as a final attempt to try and solve this issue without getting into accusumps
1) Do the welding as suggested by @gmagnus7
2) Modify / make a new oil inlet that delivers oil inside the baffle instead of where it is now next to the oil temperature sensor
1) Do the welding as suggested by @gmagnus7
2) Modify / make a new oil inlet that delivers oil inside the baffle instead of where it is now next to the oil temperature sensor
Let us know how it goes! Glad you thought it might be a good idea. Hopefully doesn't make your engine explode
Let us know how it goes! Glad you thought it might be a good idea. Hopefully doesn't make your engine explode
Done! Will obtain some new data from the track next weekend.
I noticed that the pick up is placed a bit to the left which might explain why left hand turns are challenging.
Hello, I should welcome myself to dead N55 club
The first time on track with 235/35/18 R888R's not sure if oil starvation caused overheating or just overheated.
Oh no, so sorry for your loss. It looks like you were running JB4 and a good amount of power? Did you catch the failure in a log?
Normally the car would warn you and reduce power to protect ifself if anything was seriously overheating.
