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Alright guys my turbos will be back from forced performance next week and I am going to plumb up a scavenge pump and need some advice. First off my setup is a VQ35DE Greddy twin 20g's now upgraded to forced performance black series turbos. 20g's flow 41 lbs per minute each. FP blacks flow 71 lbs per minute each. Should be a huge upgrade over the 20g's. Now I've had smoking problems from day one with the freshly overhauled 20g's from my last go around of upgrades. I drilled the oil pan and put in -10an bulkheads for the turbos to drain to as far up on the pan on both sides as possible and this didn't seem to help. The drainage system doesn't seem to be working correctly and the cartridges are filling with oil and pushing oil past the rings so I'm going with a turbowerx scavenge pump. I plan on mounting the pump in the factory a/c compressor location which is higher than the oil pan and slightly lower than the turbos. I need to know where I will need to put check valves in the return or feed system. I've seen a lot of guys run preturbo check valves but my oil supply comes from lower than the turbos so I don't see this being a need. I've also seen guys run check valves on the post scavenge pump side so the oil doesn't back flow into the turbos with the engine off which my pump will be mounted above the oil pan and should eliminate this need for a check valve also. My plan of mounting the pump between the turbos and the oil pan should eliminate the need for check valves but I want those who are running pumps to chime in on this. I will also be plumbing in a preturbo oil filter I want to keep these babies protected and keep failures to a minimum. Thanks in advance for the advice guys.
Also forgot to mention I will be using 1 pump for both turbos. Is it ok the tee the drains into the inlet side of the pump? I've seen guys do it and not have problems.
[QUOTE=Cux350z;10921600]Just not a lot of room for the pump to go. Especially with 10an fittings and hose.
Greddy turbos sit pretty high up.
The inlet line can be a 3-an. There is a very tiny restrictor in the CHRA. I think if you t them properly you will have balanced flow to both turbos.
Good luck with your project.[/Q
Im not worried about teeing the turbo feed lines at all. They will be teed off of a forced performance filter for feed. My question was teeing the turbo drain lines into the scavenge pump. I don't see a problem with it but space is very limited as most of u twin guys already know.
Well there is an improper way to T feed and return lines. Bernoulli could tell ya more. To gt the idea, try to envision the difference of a Y and T fitting and pick which one you should supply from. You can apply the same thought to a merge. Generally you want to merge two small lines into a single larger one.
Honestly I think a scavenge is overkill for how small the FEED orifice is.
Is this pump going to be spliced between the turbo CHRA and the oil pan?
Oh wow..didn't see that in the original sea of text.
OP...save yourself some time and money...abandon the scavenge pump idea on the greddy twin kit. By the time you start pumping out the CHRA it will have already backed up. Fitting stack up and hose size are getting out of control.
Good luck if you finish...but it feels like a waste of money and time.
Oh wow..didn't see that in the original sea of text.
I'd like to claim that as my gem of wisdom ... but in reality, credit due where credit deserved, that was member Kilogram ... essentially explaining that pumps are efficient at pumping and not pulling fluids through hose/pipes...
Did I listen?? NOPE! Sure didnt, probably bc I'm stupid...threw two scavenge pumps on the car, nothing changed and two weeks later the pumps were on craigslist...
I think of it like this...you have a ~1/4 line feeding your CHRAs at ~100+ psi (oil) pressure, if a ~1/2" line cant gravity drain out the bottom side of the CHRA there are other issues...after getting new CHRAs and tapping my oil pan I've had zero smoking issues.
My prediction: once the OP gets the new CHRA on the car with the tapped oil pan the smoking issues will go away.
Not much will help if your crankcase has slight positive pressure. What's your pcv setup?
Definitely no crank case pressure. I have the catch can with 2 inlets. 1 from the pcv valve and one from the rear left valve cover. I have the outlet of the catch can routed to the intake pipe on the left side turbo so there is a constant vacuum on the crank case.
I'm going to try and use -10an hose for the drains and try a more direct drain route to the oil pan before I do the scavenge pump. I was using the factory Greddy drain tubes before and used silicone hose to couple the turbo drains to the bulkheads in the oil pan and I'm not sure if it was a good enough direct drain route.. If this doesn't solve the smoking issue which I'm 100% sure was the turbos I'm not sure what to do other than the scavenge pump.
I'm going to try and use -10an hose for the drains and try a more direct drain route to the oil pan before I do the scavenge pump. I was using the factory Greddy drain tubes before and used silicone hose to couple the turbo drains to the bulkheads in the oil pan and I'm not sure if it was a good enough direct drain route.. If this doesn't solve the smoking issue which I'm 100% sure was the turbos I'm not sure what to do other than the scavenge pump.
The extra 1/8" of hose diameter isnt the issue nor is going to solve the problem. Having an absolute direct downhill-flowing path is good but as long as the CHRA is above the oil pan tap it'll drain ... I have a small valley in my hoses and it doesnt matter, especially since the CHRAs have a pressure-head pushing the oil back into the pan.
get the blowers back on the car and get the hoses connected and see how the system does.
Also forced performance did a failure analysis on my turbos. Their description was that the oil I was running was a bit thin for the mitsu turbos that mixed with steel thrust bearings and some small particle damage is what caused the failure in the passenger side turbo. I will be switching back to AMSoil 10w-40 or possible thicker. I've been running mobil1 0w-40. So the chra was properly rebuilt last time. Minus the steal thrust bearings which apparently are no good for mitsu turbos. They now have brass thrust bearings installed. Now that I know the CHRA's are good I can try the new drainage system without the scavenge pump and see how it goes. Here's a pic of clean liquid oil in my exhaust tip for reference. There's only 1 route for clean liquid oil to get into an exhaust system and thats from turbo seals. If it was a head gasket or engine problem that oil would not be clean. I will also post a pic of the failed turbo vs the good turbo. I obviously had an oil issue with the failed turbo. The passenger side turbo is the turbo with the oil drainage issue. The drivers side looks like it was draining just fine and not pushing oil.
The biggest thing is to have a nice sloping line. Now...a bigger line will leave more volume for the drain.
Under normal conditions you should have oil in the lower pan and to the same level in the hoses. I have my hoses all the way at the bottom of the pan in a spacer with -8an lines.
The feed line orifice is SMALL like really small. Maybe bench test how much oil you can make pump through them at 120psi (use a compressor and fittings to convert)
I am eliminating the feed line orifices at the turbos and will be teeing off 2 -4an feed lines from the forced performance preturbo filter. It has a built in restrictor. I got 2 banjo -4an feed line adapters for the turbo feeds and also got npt threaded drain adapters so I can adapt to -10an drains. Hopefully this setup works and I won't have to mess with the scavenge pump. But if my smoking problems persist I will have to figure out the scavenge pump idea. I should have it all back together next weekend I'll keep u guys posted and let u know how it goes. I have to get this smoking problem taken care of it's super embarrassing to drive the car like that haha.
Have you driven the car without the turbos? You may have fried rings.
Nah compression and leak down tests were good. If the motor was fried it would surely smoke on start up. It doesn't start smoking until the turbos warm up. Also the clean liquid oil in the exhaust tips indicates turbos for sure. If the rings were shot it wouldn't be clean oil in the exhaust.
I suspected it might be valve seals since I changed them to the Z1 viton seals when I did cams and springs but once again it would be burnt oil not clean oil in the exhaust. And it would smoke more on start up and high vacuum situations.
Exapump will fit on the outside side of the driver's side frame rail (on a g35 and I think 350z). It needs to be positioned perfectly to not hit the fender liner and leave room for the fittings. I use 8an and it works well. It continues to pump using a delay-off relay for 60 secs after engine off.
For low mount turbos a scavenge pump is the only way. It works fine. 0 smoke. If you can get away without it, I would as you have 1 less part to fail. The exapump is also expensive (but deemed most reliable over other options).
I just reread it but didn't see the brand of failed scavenger pump........
cliff notes= scavenger pump failed in under 10 minutes of use, supposedly because of high oil temps. Owner said he never rev'd over 3000 (on last page)
10-20-2017, 08:43 AM
Twin turbo scavenge pump setups
