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Discussion Starter · #1 ·
Dammit. This is the second time this has happened to me. I was running last weekend at Little Talladega when I suddenly started hearing a knocking sound, and immediately pulled off and shut down. My worst fears have been confirmed in that it was the number 4 bearing. Has anyone else had these type of issues? I'm so frustrated I can't hardly see straight. I love the car, but it just keeps breaking my heart. I'm running a large oil cooler to help with the temp issues (that seems to be working very well, btw), and had bored the oil pump and galley to the oil pan to improve flow. However, the oil pressure would drop later in runs, and I'm guessing this was the cause of some momentary oil starvation??? I'm looking to those of you who have been doing tracking successfully for a while now. Are you running the stock pump? What kind of oil pressures will you see toward the end of a run? Is there something else I should be looking at as a culprit? I so badly want to keep running the car at track events, but I can't keep having this happen. Very depressed....
 

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Same thing happened to me in the 4A-GE last august.

I believe an Accusump is the solution for you. That's what Jeff Watson uses IIRC.
 

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Discussion Starter · #3 ·
Yeah, I had looked into those myself before. Problem is finding room for it under the hood of a full-accessory vehicle - those suckers are big! Also, I'm really thinking my oiling system just wasn't keeping up in general. When I pulled off, it was only running about 14 pounds of pressure (not sure what it was doing under throttle, but I noticed the knock right after a long sweeping, off-throttle turn). I had trap doors installed in the oil pan to keep from starving the pickup, but I'm thinking that won't matter if there isn't enough pressure. Any feedback is appreciated.
 

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I thought the oil pan was baffled stock?

What was your oil level when you pulled off-track?

In my AE86 the PCV system was what killed me. Turn 2 at PR (long left turn constant radius) at high speed right on the ass of a WRX caused enough oil to travel out the PCV into the intake that it burned off and starved the motor.

If it's an oil level thing then a catch can may be in order as well.
 

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Discussion Starter · #6 ·
I don't believe the stock pan is baffled, by I actually had them install one-way trap doors to keep oil from sloshing away from the pickup. When I came off, I checked the oil level and it was just under the "full" line (right where it was at the beginning of the day). I am currently running a catch can, and instead of venting it, have it routed into the intake pipe to help with crankcase pressure. I don't appear to have lost any volume of oil.

I actually realized that the accusump wouldn't need to go in the engine bay later on myself. Thats a pretty good idea, frankly. I guess I'm concerned that this wouldn't solve my problem though as it appears that my pressure was just low in general. I believe the accusump will begin to dump when pressure drops below 20psi. It looks to me like I may have been below that in general however.

So maybe my question should be... does everyone here who tracks the car still run the stock pump? I see Toga makes an upgraded unit, but its only for NA cars, and I haven't been able to find any other ones. Also, have you all ported your stock pump and the galley to the pan in order to increase flow? I believe this may also have the effect of lowering pressure which maybe I shouldn't be doing for a heavy duty track car. I'm also guessing that running the large oil cooler (holds 1.57 qts by itself) and lines had an additional effect of lowering pressure, but I think most of us are running some sort of sizeable cooler, so not sure if this had any unintended consequences. As I rebuild this time, I want to make sure I address anything that I possibly can.

Thanks again for everyones feedback.
 

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Do you overfill the oil for track days? Adding 0.5-1quart extra helps oil starvation issues. Combine it with an accumsump and you should be ok. Every track supra runs the stock oil pump AFAIK, as there are no alternatives.
 

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quick said:
Same thing happened to me in the 4A-GE last august.

I believe an Accusump is the solution for you. That's what Jeff Watson uses IIRC.
I've heard some of the hardcore Vette road racers talking about Accusump as well. I'm going to look into it for the future when I'm actually FAST enough in the corners to really be worried about this. :)
 

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MikeS10 said:
can't you mount those accusumps behind the back seats or towards the back of the car? i don't know that it has to be in the engine bay.......?
A few people put the dry sump oil tank in the trunk and run the lines to the engine bay. You need to put heating pads onto the oil tank for pre-heating from what i've read also.



Heres some good information on dry sump systems,
http://www.skylinesaustralia.com/forums/index.php?showtopic=86055&hl=dry+sump

http://www.petersonfluidsys.com/
 

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Discussion Starter · #10 ·
Yeah, I had actually been looking into a dry sump system. I even saw that Moroso makes a dry sump pan for the Supra, but I have no idea where you would put the pump. I think you'd have to ditch some accessories like power steering or a/c in order to make room. I'm not looking to do that to this car just yet.
 

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TGIF 1 said:
Yeah, I had actually been looking into a dry sump system. I even saw that Moroso makes a dry sump pan for the Supra, but I have no idea where you would put the pump. I think you'd have to ditch some accessories like power steering or a/c in order to make room. I'm not looking to do that to this car just yet.
It seems people are ditching the ac compressor and modifying the mounts for the dry-sump pump.
 

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Discussion Starter · #13 ·
They are 1/2" lines to and from the cooler.
 

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Discussion Starter · #15 ·
I had been, but I wasn't convinced it was working properly, so I bypassed it. Here in Atlanta, I don't have much problem with it being too cold out, and I never run the car hard until I get the temps up.
 

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Discussion Starter · #18 ·
slowwrx said:
I can drive you to the chevy dealer, just give me a ring.

PUSH PUSH NUDGE NUDGE
Get thee behind me, Satan!!! :)
I'm gonna play with this one more time before I throw in the towel (of course I said that last time, too)
 

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The factory setup is baffled.

What bearing clearances do you run and what type of bearing?

Is your oil pump shimmed?

What weight oil are you running?

Are you sure that you are not detonating which can kill bearings?
 

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Discussion Starter · #20 ·
I'm running Clevite bearings.

I'm probably not following the question on the oil pump being shimmed. I did have the holes slightly enlarged to increase flow, along with the galley leading to the pan. I would assume these changes would have the impact of dropping pressure somewhat, but the tradeoff being more flow.

I was running Amsoil 10w30. I was using their version that is designed for turbo engines and is supposed to be more heat tolerant. However, the more looking I do, the more I wonder if it wasn't a problem with the oil. I just got some Royal Purple 40 weight racing oil which I think I will give a shot.

As far as detonation, I can't be sure as I'm not running any electronics to be able to tell. It seems unlikely though as I'm running about 20psi, on 100 octane and am using Derek's injection kit with a mix of 50% methanol / 50% distilled water.

I'm pretty sure the drop in oil pressure (less than 20 lbs) later in the run was what killed me. But the big question is what is causing that drop. My setup just doesn't seem to be that different from other people's, except for the oil. Its hard to believe that the Amsoil would break down like that, but off the track, I would run a steady 45 - 60 psi of pressure, even under hard street runs. Only after some time on the track would it dip down.

Thanks again to everyone here trying to help me out.

Ron
 
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