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  #691  
Old 29-12-2016, 02:33 PM
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And here is another video where I demonstrate how to test ignition timing on the DOHC EJ motors with coil on plug. Given that the ECU i use is a wire in as opposed to a plug in, and there could potentially be issues with the wiring polarity of the crank angle sensor, and also that the base settings im using arent specifically for a forester XT. It is important that I double check the timing that the ECU thinks its giving and measure it against what it is actually giving.

Plus a quick basic run down of using the on board trigger scope built into the G4+ platforms. I thought thats a pretty cool feature.

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  #692  
Old 30-12-2016, 12:49 AM
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Just for info and not sure if it helps at all but when I had my GC8 with a front mounted GTX35R I simply had a 1mm restrictor on top of the turbo and a drain from turbo to sump. Nothing fancy just a -10AN (may even have been -8AN). I just let gravity do it's thing and the setup worked extremely well.









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  #693  
Old 30-12-2016, 06:26 AM
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Yeah. But you have a better (longer) fall out of the turbo. The problem i am wanting to avoid is kinda hard to explain. Its due to there only being such a short distance out of turbo before its into the collector. Turbo oil seals are like a metal piston ring. They only seal against oil that runs/splashs past them on its way out of the core. As soon as oil backs up inside the core, oil basically overflows out the seals. The seals are very finnicky and dont actually seal very well. (Remember that shaft has to spin 150000 rpms, and gets spastic hot.)

I am surprised you got it to work with the drain entering into the sump at the bottom though. All the research i have found state that as a bad idea, ideally you want the drain tube to drain into an air space, not into an area submerged by oil.

The reason i wanted as large as possible diameter right out of turbo is bescause if liquid sloshs around in the collector (during braking / cornering) then as soon as the level covers over the smaller hole, that is when liquid will start backing up in the fitting and eventually the core. Just the resistence of the liquid its self could be enough to cause it to back up. With the new alloy one im hoping to avoid that situation by going alot larger out of the turbo into the collector. And i did also want better clearance to the road.

Both collectors worked well in the garage testing ive done. The scavenger pump is capable of flowing more oil than the turbo can drain. The only actual issues ive had initially were actually due to not running the pump enough after shutdown/before start up. And the accusunp leaking back when the pump was off. The pump is controlled via the ECU, and i have configured the ECU to keep alive for 30 seconds after shutdown allowing the scavenger pump and cooling fans to run on. And i have sorted the accusump solenoid out. I replaced with a direct acting unit. And i put it in the correct direction to hold pressure after shutdown. Now holds 6.5 bar perfectly.

The reason for the 0.035 restrictor is Garrett specify ballbearing turbos to have 45psi max oil supply. 0.035 is very common size used to achieve that oil pressure (more so in the USA where everything is measured in inch). 1mm works fine and is also very common to use on the Garrett BB turbos to achieve the pressure reduction. 1mm works fine on a setup with an ideal drain. But i figure its best to opt slightly lower on a setup with a less than ideal drain. I wont be using the 0.030 restrictor either (it actually arrived and measures 0.040"/1mm, so the shop sent the wrong part out anyways.)

And interestingly my engine now has significantly more oil pressure (when hot) than it ever did previously. It still peaks at 6-6.5 bar at the engine, so i know the releif is working. But the oil pressure leading up to releif seams higher relative to rpms. I dont know if because the oil grade 5w50 motul. Or because the massive oil filter presents less restriction?
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Last edited by Bram; 30-12-2016 at 06:29 AM.
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  #694  
Old 30-12-2016, 09:20 AM
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Like I said not sure if it helps or not but as far as my setup went it did over 30,000 miles like that, numerous track days and about 25 drag runs without one single issue. The proof is in the pudding as they say. Sounds like you're on the way to sorting it though so all good.
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  #695  
Old 30-12-2016, 10:07 AM
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Cool. Well after seeing that, then im pretty confident my system will be all good out in the real world.
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  #696  
Old 30-12-2016, 04:53 PM
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How is your turbo sump/collector vented ?

I have run several turbo's low mount, current one uses a piece of 40x40mm square tube about 120mm long that bolts to the bottom of turbo oil drain(crush tubes in bolt holes).... that is all the sump that is required. The square tube has a -6 fitting welded in bottom corner that the scavenge pump sucks on and a -6 vent in the top that is plumbed to catch can, pretty much atmo.

Have run garrett and precision turbo's like this with no restrictor.

What is the issue you are having ?
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  #697  
Old 30-12-2016, 06:10 PM
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Quote:
Originally Posted by GTLeggy View Post
How is your turbo sump/collector vented ?

I have run several turbo's low mount, current one uses a piece of 40x40mm square tube about 120mm long that bolts to the bottom of turbo oil drain(crush tubes in bolt holes).... that is all the sump that is required. The square tube has a -6 fitting welded in bottom corner that the scavenge pump sucks on and a -6 vent in the top that is plumbed to catch can, pretty much atmo.

Have run garrett and precision turbo's like this with no restrictor.

What is the issue you are having ?
Right now i dont think there is an issue. But i havent properly driven on it yet. Only idling and free-revving in the garage. I want it to work 100% right when the car is driven and raced again. and that is why i rebuilt the sump. I am trying to do everything i can in order to anticipate potential problems and improve things as best as i can.

Initially i had it backing up oil. And i did also have a small amount of oil in the exhaust and intercooler piping that overflowed from a oil filled core. But i think that was 2 problems i have now already fixed. 1st was do to with the accusump discharging (solenoid was leaking back after shutdown with the scavenge pump off) and also not giving the scavenge pump enough time to clear oil before/after running. Which i am pretty confident was what led to the overfill and oil past the seals. So a leak-free solenoid was fitted, and i have the pump active for 30secs after engine shutdown.

I did also go from a 1mm restrictor down to a slightly smaller 0.035" restrictor. As potential trouble shooting. 1mm is approx 0.040". From my research, 1mm and 0.035" are both common sizes to use on BB Garrett cores. Garrett specify a max of 45psi oil pressure, hence why a restrictor is used. Journal bearing turbos do not want a restrictor, and they function best at as much oil pressure as you can feed them. But BB turbos supposedly dont need such high pressure, and Garrett even go so far as to say between 40 and 45 psi. Obviously its very difficult to actually measure the pressure drop over the restrictor. So i did some looking around and chose the 0.035" size as a compromise between the probably better 1mm size, and the potential oil clearing issues from a low mount turbo.

The 2nd issue was i dont think i had the turbo core clocked perfectly, and also had too much angle of the rotation axis away from parallel. So i reclocked the core better. And i loosened the V-band turbine inlet and rotated it and got the turbo sitting more hotizontal. Before it had over 15° away from horizontal. Now i have just under 15° away from horizontal. Garrett specify no more than 15° in thier tech section. And with core clocking, i had it so the coolant in was lower than coolant out. But probably a bit too much. Now i have it slightly less. Meaning the drain is closer to vertical.

But since i did all that it was all good. But because i slightly reposititioned my turbo. The first oil collector i built (ss316 round one) was not at a good angle/hieght. And i had been doing research about turbo draining and alot of problems were over come by using larger port directly out of the core. (Ie NOT those AN10 adapters like i was originally using.)

So the potential bottle neck in the 45° AN10 union and drain fitting, plus also the now no longer perfect angle on the stainless steel collector, led me to build a new collector out of aluminium. As seen in that youtube video i just put up. Again, that was more preventing potential problems rather than fixing actual problems. I wanted to be 100% happy with the setup before going in for tuning next year.

Re your question about the venting. The collector is vented to the 2 catch cans. Basically i ran 2 hoses down from the drain fitting on the catch cans directly to the oil collector. 2 reasons. First is to prevent vacuum in the collector from the scavenge pump. The other was to allow the catch cans to self drain oil back to the engine. I welded up the base of the weld fittings for the catchcan drain before i welded them to the tank. Then redrilled the wholes a bit smaller so they arent too free flowing. I actually drilled each one out to 1.5mm. But on the video i daid 1mm by mistake.
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Last edited by Bram; 30-12-2016 at 08:20 PM.
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  #698  
Old 30-12-2016, 08:24 PM
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I have run large garrett and precision turbo's with a -8 drain etc, the volume of your drain isn't the issue. You think about how much oil can enter the core via a 1mm hole.

You say your running the drain of your catch cans to the turbo's sump/collector ?? I would suggest this is a bad move, biggest issue people have in these low mount situations is stopping the pressure etc on the vent of the sump/collector/turbo.... making it breath/vent through a line anything other than clear to atmo is a problem, and having oil from your can's also filling the turbo's sump is a very bad idea.

My scavenge pump stop's with the engine, the sump on turbo would be lucky to be 180ml, never had an issue.
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  #699  
Old 30-12-2016, 08:26 PM
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Quote:
Originally Posted by GTLeggy View Post
How is your turbo sump/collector vented ?

I have run several turbo's low mount, current one uses a piece of 40x40mm square tube about 120mm long that bolts to the bottom of turbo oil drain(crush tubes in bolt holes).... that is all the sump that is required. The square tube has a -6 fitting welded in bottom corner that the scavenge pump sucks on and a -6 vent in the top that is plumbed to catch can, pretty much atmo.

Have run garrett and precision turbo's like this with no restrictor.

What is the issue you are having ?
Wish i had of made my setup so simple. In typical Bram style, i always opt for the most complex over the top solution to any problem. Haha. Anyways, that sounds like effectively the same as what i have but way less complicated. So if that works for you, then i feel pretty good thqt my setup will be adequate.

BTW. What scavenge pump do you run?
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  #700  
Old 30-12-2016, 08:34 PM
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Quote:
Originally Posted by GTLeggy View Post
I have run large garrett and precision turbo's with a -8 drain etc, the volume of your drain isn't the issue. You think about how much oil can enter the core via a 1mm hole.

You say your running the drain of your catch cans to the turbo's sump/collector ?? I would suggest this is a bad move, biggest issue people have in these low mount situations is stopping the pressure etc on the vent of the sump/collector/turbo.... making it breath/vent through a line anything other than clear to atmo is a problem, and having oil from your can's also filling the turbo's sump is a very bad idea.

My scavenge pump stop's with the engine, the sump on turbo would be lucky to be 180ml, never had an issue.
Ah ok. I thought having the catch cans drain into the collector would be ok? My car doesnt really collect a massive amount of oil in the catch cans. Like realistically its probably a few drops per km. So its not like its gonna be flooding it. Id say for the most part the drain tube would be clear air, and everyonce in a while a drop would pull through. There is 2 catch cans. Each independant of each other. And each draining seperately into the turbo oil collector. Each one uses a -4 nylon braided hose directly into the collector. As said, each one has a 1.5mm hole at the weld fitting on the collector. I did this as i was worried that they would let TOO much air into the collector.

Are you saying more so because some goop from the cans could potentially clog the venting up? I did fully clean the cans and plumbing out before doing this setup. And if the cans are constantly draining, then hopefully none of that nasty goops could even exist.

The catch cans are effectively vent to atmo anyways. Well sorry one is vent to atmo. The other still connects to the intake manifold via the PCV valve.
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Last edited by Bram; 30-12-2016 at 08:37 PM.
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