Has anyone come up with a solution to limiting the oil pressure to the turbos? My car still smokes out the exhaust alot at idle and recently ive found out APS uses banjo fittings at the turbos. How do you go about putting a restrictor on that? Thanks!

 

Wasn't that resolved with keeping oil at the L level of your dipstick and
shortening the oil return lines?

 

Thats what i understood too but keeping the oil that low kind of bothers me. I was hoping something new and better has been found. I dont know if keeping the oil around the L level on the dip stick is detrimental in any way to the motor though. Maybe its fine. It just seems a simple restrictor on the feed line would work, i just dont know what kind of restrictor.

 

The oil seals in your turbo are likely bad. Happened with my kit back in 05. I had to send them back to APS. I never had any more smoking problems after that.

 

I don't know about seals always being the culprit. According to Blouch (I think that's who I got this from), oil should never even make it to the seals. Apparently the seals are primarily for keeping boost out, not oil in per se. Garrett cartridges have this oil slinger design that should preclude oil approaching the seals (unless something untoward occurs like increased crankcase pressure or blocked return line). That said, with my 700bb, I sometimes notice an oil film in the charge pipe and drop sitting on the bottom of the compressor housing. Never enough to cause smoking or oil on the floor, but I hate dirty pipes...

 

I know the article you are talking about. All I'm saying is, my original APS/Garrett turbos smoked from day one. The turbos were replaced, and all decel/idle smoking ceased. According to APS, the seals were the culprit. No changes were made to the return lines or the PCV system.

 

Stop making me worry about my turbos!

 

LOL, you are in the clear if your turbos made it the first 100 miles w/o smoking

 

Chris is correct. I had an issue with one of my turbos from day 1 and had it replaced and no more issue. It isn't a pressure thing, restrictor thing, or some other speculative thing.... it is the seals on the turbo itself.

As far as keeping the level at "L", you do realize the pickup along with the pan have been extended to account for change in oil level?

 

No need for restrictors. I think Ziv is correct, if they are going to smoke they will do it very soon after the initial install.

Also, not all the APS kits are subject to slight smoking when the oil level is full.

My APS kit on the G35 never smoked and I always ran the oil completely full, at the H level and checked it every saturday morning.

Running at the L level is not a problem though because the pan is deeper and the oil pickup has been modified accordingly. I'm just saying that there are APS cars out there (probably a number of them) that are not subject to this sensitivity of the oil return path and higher crankcase pressure and/or whatever APS explained about it in the memo on their website. Not all APS cars need to run at the lower level, my guess is that the vast majority can be run at the H level without issue.

 

That's very true. After my turbos were replaced, I ran a full 6qts with no problems. If you really think about it, the level shouldn't even matter since APS returns their oil lines below oil level anyways.

 

Im beginning to see what you are saying. This pic isnt to scale but IIRC the turbos are sitting above the oil pan and close to the top of the level of the dip stick.


My car left the shop around Spring 2005, and my exhausts only smokes when the weather is cold outside so it wasnt until November when i first noticed the cloud of white smoke out the exhaust while idling in a parking lot. Now I just dont want to foot the bill of dropping the turbos at a shop again.

 

May i have a link to that memo? I cant find it on APS's sight.

 

http://www.airpowersystems.com/350z/...ain_notice.htm

 

Thank you sir.

 

that's the one

I actually traded a couple of emails with Peter at APS on that one not because I had smoking turbos,... but because it just didn't make a lot of sense to me. If the seals are bad, they leak. If they are good then they should not leak regardless of normal crank pressure at idle or normal oil pressure.

High oil pressure I understood,.,.. High crankcase pressure to the point of stopping the oil drain flow at idle - not feeling it. For those of us that have actually tried to measure blowby and crankcase pressures, you would have to have a really sick/ill motor to get a crank pressure high enough to keep oil flowing in those drain tubes to the point of failure on the seals while the car idles! I;ve had several tell me that turbo seals don't even work that way with regards to oil flow around them and the effects of crankcase pressure to this type of failure is 'ridiculous' theory on idle smoking and especially off idle (engine braking) smoking.

Just 0.02

 

I've blocked off my crankcase vent and my car turned into the space shuttle on launch. The IC literally pooled oil within 5 mins and a drive around the block turned into a spectacle. As soon as I unblocked it (by replacing the PCV and a kinked hose coming off the PCV), the smoking started to dissipate. Crankcase pressure is a well-established mechanism for getting turbo oil seals to leak, tested by me - 100% proof positive. I spent the rest of the weekend cleaning out the IC and intake piping. FWIW, I don't think oil return is blocked so much as rerouted through a path of lesser resistance. Consider vacuum pulling oil out through the turbo seals during decel...

 

In a properaly operating system the oil pressure alone (50-90psi) resident at the seals is way higher than the crankcase pressure or the vacuum during decel, just saying if they are going to leak at idle then the oil pressure pushing on them is going to keep them leaking more so vs. crankcase pressure. I just don't see how they can leak due to crankcase pressure at idle (if they are weak) and not leak due to oil pressure alone.

I'm no expert, just opinion so no worries.

 

This is something im not sure of too? Are the oil drains under pressure from the supply side or are the just gravity drained?? The supply pressure should push the oil into the sump even with very high crank case pressure so are the drain lines not under any pressure at all??

 

There's no pressure after the bearings, turbos rely 100% on gravity to drain the oil out of the CHRA.