There is a lot of speculation going on. But you have to admit that something that you think is right, or have been told is right, is not right.
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There is a lot of speculation going on. But you have to admit that something that you think is right, or have been told is right, is not right.
I agree. Again, I appreciate all the help. I know everyone wants to help and see this car be reliable.Quote:
Originally Posted by D Clary
This goes to Chad's point that people have not read the whole thread.Quote:
Originally Posted by RogerB
As I have read the entire thread; this build is closer to being finished or quickly, and sadly ended.
For your sake, I really hope you stick to it long enough to figure it out and get some really good track days.
I also have my own selfish reasons that these problems get fixed. You are posting some of the best 818 race data and that helps boost (pun intended) the 818's value. I think that you have individually invested more time and money into the 818 than anyone on this forum. This benefits all 818 owners, including me. If you throw in the towel now, it is a defeat for not just you, but the 818 platform.
When people ask me about the performance of the 818, I bring up stuff that you have posted:
Quote:
The 818R will dominate 2nd, 3rd, 4th gear tracks against the Corvette's.
Quote:
...4. The car is faster than the Lotus 2 Eleven race car records (1:59.3) on this race track Configuration...
Now, get a wrench, spend another 8 hours under the car, and order another $500 in parts!!!Quote:
...5. I was faster than 996 based Factory Porsche Cup cars out there....
Can you get any sponsorship money with logo advertising?
I'll just throw this out there, that I'm willing to help machine parts (for the cost of material) if it helps you solve these problems (haven't forgotten about that steering rack extension piece you wanted either if you end up keeping the car)
I have also followed Chad's thread since the beginning while I was waiting for my kit to arrive. As I to have an R model there are some selfish motivations. My problem is Chad selling it for pennies on the dollar, ( and 25k is pennies for his roller) then someone fixes it with a tune or a motor, whatever. It just turns into one of the many failure kits an I think Chad has worked way to hard to see that happen. I think he is in a spin and needs a break. When there is time to look at things objectively sometimes the answer is right there.
Attachment 43594
please take a look, MAF seems odd?
Thanks for graphing that. The MAF could just be a result of everything else that's going on. The boost/wastegate numbers suggest the engine was ingesting more air toward the end of the log, so the MAF should have trended up, too, which it did. The ignition timing is the red flag to me. A 3-4 degree drop in advance would certainly be felt as a power drop off. It reduces cylinder pressures, sends unburnt fuel out the exhaust valves, greatly increases exhaust gas temperatures that are fed directly to the oil-cooled turbo, and will require the wastegate to close to keep spinning the turbo enough to sustain boost. So my question is, why is the ecu pulling timing? My only guess is the knock sensor. Do you dare try to run with the knock sensor disabled?Quote:
Originally Posted by RetroRacing
Again, I'm just spit-balling like everyone else, but seems to me like the ignition advance must be in some way culpable for the power loss.
I just graphed about 13000 lines of date, and yes, running 10degrees of advance at full throttle with 15psi of boost is rather suspect, should be twice that?
I assume that is total advance timing ? Under full boost and full throttle I would expect high teens/low twenties.Quote:
Originally Posted by RetroRacing
Chad, I'm really reluctant to post, because I know you are overloaded with advice.
A problem with the oil scavenge system could explain this:-Quote:
Oil temps ran at or under 220 degree for 23 min with no problem in race conditions. Once I noticed the power dropping out and looking at the video/data oil went from 220 to 240 degrees in 20 seconds.
8 quarts of oil in the tank, sustained high rev operation delivers a lot of oil to the motor, scavenge can't keep up, the sump fills, engine beats the oil = loss of power + rapid temp rise
It would also explain why the temperature is appearing in the oil rather than the water
I searched your thread and couldn't find a close up of the scavenge pump belt drive, but the element tuning page shows a flat belt with longtitudinal ribs (like an alternator or aircon belt). Nearly every other scavenge pump system seems to use a cogged belt, more like a timing belt. Could it be as simple as belt slip at high revs?
It's probably $20 to trial fix it, with a new belt and a can of belt grip?
And where do you fit in the timing retard in this?Quote:
Originally Posted by DodgyTim
Besides, what's the true reason to run a knock sensor on a race engine? If it's a race engine, it should already have a perfectly tuned timing map to prevent knocking, hence no need for the sensor. But that might be off the problem here, just curious to understand why.
The belt is the same as a stock A/C belt. The car is still in my trailer in a "Time Out". I'll check that out.Quote:
Originally Posted by DodgyTim
I do want to check the knock sensor also.
There's a youtube video on how to test knock sensors too if you google "wrx knock sensor install". I had a friend over torque his and break it. Doesn't seem likely here though. I have no dry sump experience but I have seen lots of photos of kits with the toothed timing belt style. It does seem plausible that a standard ribbed belt, especially if not tensioned well, could slip at higher rpms and cause issues. I think the dry sump is one big difference on your car vs other 818R's that are on this forum.
http://www.reneswiss.com/subaru/knock.jpg
A very experienced racer friend of mine who has worked with dry slumped systems over 20 years read this with me tonight and agreed that it looks like the oil in the dry sump setup is foaming and casing all the issues.
I may have found a possible solution if the dry sump oil pump belt is tight. A fellow racer suggested this.
http://www.spintric.com/index.htm
And video from last test.
https://www.youtube.com/watch?v=iIuzvtT2aRE
Looking at the graph, here is what I see. Whether it is the problem or not, there is an issue with timing, in that it gets progressively more retarded (literally, no figuratively) under full throttle, as you progress through the session. It's to the point that under full throttle and boost, it's running at 10 degrees, half of what is should be. I don't know what triggers the Dynamic advance to pull 5.5 degrees of timing out, but it almost seems like the computer is learning, pulling out more and more total advance until total advance is at 15-16, and dynamic is taking an additional 5.
When the engine fires normally, the fire burns completely (or nearly so) within the combustion chamber. The heat is kept within the combustion chamber, and as the pressure drops during the power stroke, the superheated gasses cool. As the power stroke occurs, the cylinder absorbs the heat, and when the exhaust valve opens, the burned cool mixture is blown out of the cylinder and combustion chamber.
When timing is retarded, peak pressure and heat is delayed, and is not confined to the combustion chamber. Delayed ignition causes the peak heat and pressure to occur in the cylinder body itself. The flame actually burns the lubricating oil off the cylinder walls, causing more friction. As the combusting mixture is not under high compression, it is less dense, again causing further delays in the burn. When the exhaust valve opens, extremely hot, still burning gasses are blown out the exhaust port. past the valve. This flame heats the valve red hot, and superheats the head, manifold and turbo. Running an engine retarded for any length of time, under load, will cause valve burn out, and excess wear to the rings, piston, and cylinder.
So, before spending anymore money on parts, maybe pulling less timing? Again, just a rookie at all this turbo-computer stuff, but my mom sais I'm special!
Jeff
BTW, I would never assume that the water temp sender is correct when it tells you water temp is fine. Everyone thinks its the oil temp sender that is that is faulty because it reads a number we don't like, but it's the truly evil sensor that tells you what you want to believe......
I'm 85% positive after talking to some highly regarded people that it is an "Oil Aeration" problem. That would cause the "engine braking" performance loss (air is not a good lubricant), and inefficient oil coolers, and heat spike. Once the oil gets too much air (revving high only makes things worse for aeration, I was shifting sooner than I normally to see if it kept temps down), friction increases, cooling efficiency decreases. Double trouble.
In the last video, you can see the oil temp rise 20 degrees in 20 seconds once I feel the performance loss (oil temp gauge is above brake bias knob). The oil tank/oil gets too saturated with air after awhile..... It happens right before I pull off the track into the pits.
EDIT- right around 22:13 is when I notice power loss, watch the gauge..... 220-to 240 really quick before I pull off. I have been saving the motor every time I have pulled off once I felt the performance decrease. I have been cutting open my oil filters and everything has been good to this point. I need to cut this one open also. It pays to have a great "@$$-o-meter"
From my tuner- he has not seen the oil cooling ducting I have done since the last tune (and additional two coolers).
"The log actually looks great. Boost is well controlled even as dynamic load changes and the car is knock free aside for a tiny zone off load in the midrange where there might be a bit less than 1* too much timing which shows up as the fine learned knock. Under the whip, the car appears to be damn near perfect. The only thing I did notice is that timing seems to be affected by either a coolant temp or intake temp compensation as it seems to be proactively pulling a degree or so of timing under WOT as either intake air temp or coolant temp rises during the run. Without seeing those values logged, it is impossible for me to say which is the case. Given that the logs look very good from a knock perspective, I could reduce the influence of rising temps on proactively reducing timing.
Having said that, not having the compensations as active would only add back a little over 1* of timing. That would translate to roughly 6-8 whp at most. That would be barely palpable from the seat of your pants.
As for the high oil temps, there is nothing in the logs that point to anything that would contribute to that. So unfortunately I really can't help with remedying that based on the information provided. I can say that while I tend to work with more guys in TT style racing where few laps are typically run, I have not had any oil temp issues even on cars with over double the power of your car and much smaller oil coolers. The biggest thing would be efficiently channeling the air through the heat exchanger so that it is as efficient as possible. Having a ton of heat exchanger surface area is useless if ambient air cannot flow through the core and pull heat out of the fluid."
Needless to say, I just spent another $800 on stuff for this car........ http://www.spintric.com/index.htm The Engineer says this will cure my problem...... why am I so skeptical :P
I have 2 water temp senders. Stock and aftermarket. They both read the same. Technically 3 kinda if you count the Accessport (ecu).Quote:
Originally Posted by RetroRacing
Thats what I have working on the last few days. Makes more sense than other things, especially when the tuner says everything looks good.Quote:
Originally Posted by Flamshackle
The tuner says 10 degrees of timing at WOT is right? He says the ECU is pulling a "degree or two" of timing in response to something (guessing heat related - intake or engine) but a degree or two doesn't get you down to 10 degrees of total advance does it?
This is a foreign language to me. So I dont know. Maybe it has something to do with the detune I needed to stay under a certain hp maybe? I dont know. I shot him an email.Quote:
Originally Posted by Hindsight
How are you going to plumb the separated air from the Spintric that goes to your tank? There aren't enough fittings on the tank to have it as a separate line. And reading the Technical page I don't think you should plumb it to the same line coming from the vent in the heads. It's still about half oil, half air. Of course ARE will sell you a special tank top with the needed fitting!
I talked to Phil about the Spintric before I ordered my dry sump, he said there is no need for one. But then again he runs Time Attack so maybe he never sees this problem.
I hope this fixes your issue! Although I'm not looking forward to another $800 myself. There's also no room for me to mount the Spintric before the oil cooler, it would have to go behind it.
I also wonder if the way you have your PCV is plumbed if it's contributing to the problem of excess air. Maybe the hose from the old PCV crankcase vent should simply be plugged? I think I'll try that first before ordering the Spintric.
And wouldn't air in the oil show as a loss of oil pressure???
I understand Chad. I'm a former air-cooled VW guy so not too far from your Porsche experience. Mechanical advance distributors on air-cooled engines make it easy to not have to worry about stuff like that.
I am curious as to what your tuner says because even a 4 or 5 degree timing retard will provide a very noticeable power loss. 10 degrees is huge. The tuner could be correct in stating that the timing changes are in response to something else, but the most important thing here is that this is a very important red flag in troubleshooting the issue.
You just get a -12AN tee for the top vent. Then add it to that. My vent tank line and Spintric line will go to the top of the tank. You just make sure everything is "downhill" per Gary. Gary (ARE) is looking at my line routing (emailed pictures). Verbally, he said I was doing it right by not using the PCV system. He is double checking my pictures for me. The Corvette racers I race with are using the Spintric also- Lowers their oil temps and coolant temps.Quote:
Originally Posted by Sgt.Gator
Regards to Phil not using one. He also seems to think running 260+ oil temps are fine....lol
I'm just hoping this works, but for the first time I can grasp the cause and effect instead of chasing it with oil coolers. Heck, I might be able to remove my rear oil cooler and keep the 2 up front in the clean air. Fingers-crossed.
The dampening on my oil pressure gauge would not show the fast pressure fluctuations, but I can see them in the oil lines (moving/pumping).
From tuner:Quote:
Originally Posted by Hindsight
"IIRC that was the part of the log that caught my attention as well too. Timing should be higher up top and was on previous forays in to WOT in the same load/rpm zone. There are no timing de-increments due to knock so there has to be a timing compensation in play. Without seeing coolant temp and intake temp logged I don't know for certain. I'm guessing either (or both) are getting very high towards the end of your session and bringing those proactive compensations in to play. Since you are running better fuel than you were tuned on I can reduce the influence of those comps and email you a new map. Next time out, log your coolant temp and intake air temp and we can adjust as needed."
That makes sense. Something is causing the timing to be pulled. I agree with the tuner that logging the IATS and ECTS will help get you to the next step. I am just confused as to why your water temps look fine but oil temps get high. The ECU doesn't look at oil temp (as you probably know) so it can't pull timing because of that. My advice is after you get the separator installed, make sure you log the intake and coolant temp sensors and see what happens.
Sounds like progress, good luck, check your oil filter for signs of wear.
Keep us in the loop!
The 5 whys:
This happened
Why?
Because of this.
Why?
Because of this.
Why?
Because of this.
Why?
Because of this.
Why?
Because of this...which is the true root cause.
It's what they teach at work. If you stop at the first why you apply bandaids. Looks like we're getting to the end of the "5 whys"
The coolant peaked at 210 or 212 IIRC. The IAT sender that I plumbed after the awic core/right before throttle body is 130-139 degrees (throttle floored) very dependant on right foot.
My experience is much like Retro and Hindsight timing retards under load at high RPM the engine temp goes up oil first then the water. We raced Datsun 510's and 240Z's back when, the Datsun Comp headers would hit the chassis and Steering box (510). To bend the header the 1/4-1/2 inch for clearance we would run the engine up too 4500rpm retarded timing from 28* to 10-15* which would glow the header red hot (in very little time) and bend the header problem solved.
I agree with some of the others I would take a good look at the timing before investing in more parts.
I know you are getting a lot of input but as others have said you are so close.
With these sorts of issues its hard to determine cause from effect;)
Is the timing change caused by a temperature increase, or does a timing change for another reason cause the temp to rise? I'm certainly no tuner, so I won't comment.
If the power loss occurs immediately before the temperature rise, I'd say it is likely to be high oil level in the pan/sump
If you can feel a power loss it is likely 20-30hp??? That energy has to be going somewhere. The crank beating oil in the pan/sump may be causing the frothing and 20-30hp worth of heat is a significant amount:eek:
Because I'm a tight **se I'd always check the simple inexpensive things first, even if they are somewhat unlikely. I can't think of a way of real time measuring the oil level in the pan/sump (turning the engine off straight away and checking a dipstick when it happens is a bit extreme for the turbo :cool:) so the next easiest thing is to check the belt and maybe overdrive the pump or fit cogged belts/pulleys
Next weekend I'll have my dry sump at the track (fingers crossed). It will be interesting to compare my oil temps pre and post dry sump installation.
Really hoping this works out for you.Quote:
Originally Posted by C.Plavan
My good friend/engineer/motor inventor(rotary, 2 stroke and 4 stroke) racer of superbikes and radicals/dry sump specialist....... suggested that you should prepare for the worst. He said after watching a few of your amazing race footage video's that foamy oil will quickly damage your crank bearings.
I am sure you will already be thoughtful of this.
http://www.blackstone-labs.com/
cheap check?
Hey I work everyday with that!Quote:
Originally Posted by Mechie3
I don't understand what causes the oil to foam?
Like i said before, I have been cutting the oil filters open after each trackday when I felt the power loss. I still need to cut this one open, but so far so good.Quote:
Originally Posted by Flamshackle
This is the 818R problem solving manual.......Revision Z
http://minimemes.net/wp-content/uplo...9969536846.jpg
There's the problem. You need to throw it at the car, not the wall.