SMOKING TURBO, LAST RESORT, AND POSSIBLE SOLUTIONS
 

So I just ordered a new BNR S4 V3 CHRA in hopes that it will solve my S4 V2 smoking issue. As some of you may know, my V2 blew a tonne of oil past the piston ring seal almost 2 years ago at the track due to excess crankcase pressure.

I've since sorted out the crankcase pressure with dual vented catch cans, and an oil breather cap. It now only smokes during decel, and in between shifts when back pressure in the downpipe drops and oil feed pressure is high (ie. mid to high rpm's).

Compression and leakdown tested perfect at 180+ psi, and less than 3% leakdown. Many avenues have been explored at this point, and the only thing left to do was to order a new CHRA from BNR.

The worry of this happening again, or not being solved with a new CHRA is still present, so I kept searching for other possible solutions to prevent it.

First is the Turbosmart oil pressure regulator, and second is the TurboWerx Spartan oil scavenge pump. What do u guys think?

Does anyone run one of these and or have any thoughts on the matter? :)

Erik

For the pump, i would be afraid that any crankcase positive pressure is reported both side of the pump as soon as the pump get partially dry....I would test it to be sure but it won't help if it react this way...

Is your dual breathing system still connected to the IM ? The PCV open each time you release the gaz to put the crankcase under vacuum also ?

I never seen it but i wonder if someone could make a breather system directly on the turbo oil return. Welding a long metal pipe going up above the head with a PCV at the end of it to release any possible pressure from this side of the bloc????

On the other hand, can you have anything in your exhaust system that could make a scavenging effect and suck exhaust air a little bit when you release the pedal creating a lower pressure than what it is in the crank case at that time ?

At the point you are, i would install a lower range pressure/vac gage connected to crankcase pcv and another one into the turbo discharge down pipe to compare the pressure.(You may need some way of cooling the connection at the DP but for a temporary reading someone could be creative....

From what I've read the pump can be run dry without issues and it is self priming. I dont think crankcase pressure will be enough to prevent the pumps ability to push oil back into the block from the turbos drain, because even with the stock gravity drain setup it works fine at WOT.

Remember I am only getting smoke during decel now at 3k rpm or higher. The scavenge pump would be constantly pulling a vacuum on the turbos oil drain, and pushing/pumping the oil back into the block.

I recently hooked up my AEM digital boost gauge to a modified oil filler cap to measure crankcase pressure. Unfortunately the gauge doesn't register anything until +/- 1 PSI. So it remained at 0 psi at WOT, Part Throttle, and Deceleration which is good.

My PCV setup is over kill. Sp63 oil breather cap, DM dual vented catch cans with one between the intake manifold and PCV plate (check valve at manifold).

My only fear with running a scavenge pump is that if it fails, oil from the turbo won't be able to drain out, as the pump is in series between the turbo and the block. If I am driving a long distance, my car would pretty much become a smoke machine ��

With the Turbosmart oil pressure regulator, it caps oil pressure to 40 psi on the turbos oil feed, and retains the stock banjo bolt. With my oil pressure gauge, I've noticed that if oil pressure is kept below 50 psi during decel, there is no smoke. The issue with the pressure regulator is that it requires an oil return to the oil pan, and I'm not sure where I could tap into.

Either way, the new S4 V3 CHRA just arrived in the mail. I'll install it using the stock banjo bolt and report back. If I detect smoke and or oil consumption, I'll install the oil restrictor bolt provided by BNR, and If it still smokes, then we'll go from there :)

Thanks, Erik.

i wish the updated one works.

I was wondering if the pump could push air also or just the oil. I didn't see the type of pump head....And despite it is self priming, it may need to accumulate enough liquid before being able to push it away and only generate vacuum when there is enough oil in it...

You can monitor the pump current with a device like that.
https://www.nktechnologies.com/curre...sing-switches/
IT will let you know if the pump current fail below the threshold. regardless of it is from a short that blow the fuse or if it is an open circuit by a broken wire or burned motor...

For the oil return, you may weld a T at the turbo return or dril one in the pan....