MY 3.8 twin turbo build up. How much HP do you think?

[WydRyd]

Originally posted by speeed racr
The oil is leaking out of the air intake , up pipe compressor, and the hot housing on both turbos. There is a lot of oil collecting inside the turbo. any ideas??????

Like others have mentioned above, I also suspect you are having oil drain issues. You really need to run -10AN oil drain lines out of those turbo's. Least restriction, the better. If you have enough height in those turbo's, lose the scavenge pump and just run a drain line into the lowest point on the lower valve cover, OR, drain both turbo's back into the sump oil drain plug/point.

Alternatively, you can run an electric turbo scavenge pump made by Westech or Turbowerx or something, but electric pumps, whilst reliable and robust, DO eventually fail.

[RennSport930]

can't wait

[speeed racr]

I have tried a oil pump utilizing -10 lines from the turbos to the engine case with still the same problem of oil backing up in the turbos. I think the oil is not being allowed back into the case. I will try to route the return back to the oil tank. Thanks for everyones advise.

[Lukesportsman]

My turbo's drain isn't even -10, so how do you guys adapt? Maybe its just the small size of my TT's, but do you think running lines larger than the most restrictive orifice offering any benefit? I planned dual -8AN lines to a "T" at the sump drain on the 3.2 case.

[WydRyd]

Hmmm... as long as the drain point is lower than the oil exit passage on the turbo and there's no restrictions, then oil shouldn't be backing back up the turbo. That's bizarre!

As I said, I run a -4AN UNRESTRICTED line to my GT35R and I have no issues.

[VZ935]

I have seen it happen where the oil cannot get scavenged fast enough on a gravity feed . I have had that problem and have run the Powerhaus scavenge pump which is basically a VW oil pump.

I just dyno'd my 935 motor at Jerry Woods yesterday. Jerry has a real nice sump plate with two fittings on it for scavenging the oil. It is a beautiful billet piece . In my case of a twin turbo application it has two 3/4 inch scavenge lines. I have these two pics I took but unfortunately they don't show the sump plate . I would call Jerry and ask him about it. The motor made 720 hp at somewhat conservative boost with hybrid K27s and cleared the oil from the turbos no problem




This is the 3.6 twin I had in my GT1 R club car... It is hard to see in the photos but I gravity fed the turbo oil return into the lower valve covers with no problems

[Candelaria]

Speed racer, did you solve the oil scavange problem??? Candy.

[WERK I]

Originally posted by speeed racr
I have tried a oil pump utilizing -10 lines from the turbos to the engine case with still the same problem of oil backing up in the turbos. I think the oil is not being allowed back into the case. I will try to route the return back to the oil tank. Thanks for everyones advise.

If the crankcase is pressurized, from normal or excessive blowby through the cylinders, the gravity feed will not work. Do you see vapors pushing out the oil tank with the cap is removed when the engine is running?

[930gt-40r]

Im having the same problem right now with my 37R. I had to clock the turbo 90 degrees from the normal location via an elbow. But now the turbo sits so low on the motor that the oil runs into the turbo on shut-down when the scavange pump isnt spinning. I am running a -8 an line for the return and a -4 an for the feed, I am going to use a -10 and try to slove the problem before I rip the rest of my hair out.
Mmmmm..... a smoking exotic car FUN!!

[speeed racr]

I have got rid of the of the old set up. I am running a -4 feed with a restrictor to a 5/8 high temp hose. The return goes straight to the valve cover as a gravity drain. But the turbos are still filling up with oil.
Anyone have a match and some gas?

[930gt-40r]

Speed racer, I am going to run the -10 line like I said before. I have another idea that mabye you will like- 996 turbos use a anti drain back valve on the turbo inlets. Im going to get one and tap it for 1/8" npt so I could run a -4 line to and from it. Next time you go to mess around with your car, try starting it and shutting it off with a drain pan under the turbo and your return line off. You will see it dripping for about 20 minutes after shut down, since your scavange isnt running with the engine off, the oil gets to back up from the residual in the -4 line draining into the turbo. I get the check valve in a week, I will let you know if it solves my problem.

[Candelaria]

He also can use the 930 type "ball" check valve, this will take care of both lines, best, Candy.

[speeed racr]

Originally posted by 930gt-40r
Speed racer, I am going to run the -10 line like I said before. I have another idea that mabye you will like- 996 turbos use a anti drain back valve on the turbo inlets. Im going to get one and tap it for 1/8" npt so I could run a -4 line to and from it. Next time you go to mess around with your car, try starting it and shutting it off with a drain pan under the turbo and your return line off. You will see it dripping for about 20 minutes after shut down, since your scavange isnt running with the engine off, the oil gets to back up from the residual in the -4 line draining into the turbo. I get the check valve in a week, I will let you know if it solves my problem.

My problem is the turbos are still filling up with oil while it is running and blowing out the intake and compressor to the intercooler.

[WydRyd]

Sounds like stuffed turbo's to me... sorry to hear

[Candelaria]

You can do this test, with the exhaust taken off, so you can see the turbine wheels, take off the drain lines,start the engine, with suitable means to catch the oil start the car, see how the oil flows out and check the turbine if it leaks oil thru them toward the exhaust side and the compressor side,(always keep an eye the oil level keeping adding oil as needed), if it still leaks oil thru the bearings, then you probably have a bad set of turbos, hope this helps. Candy.

[930gt-40r]

speed racer, your problem is that your turbos are not high enough in the car to gravity feed them in those lower valve covers. you need to use a scavange pump and a large return. Didnt you have a scavange on there before?
Oiling problems suck, I am really pissed about my turbo leaking because this is the first Porsche motor that I did that didnt leak oil and now for this b/s.

Candy, thats what I did minus taking the exhaust off. I saw that the turbo has about a drop every second for about 6-7 mins. after the car is shut off. All those drops eventually add up enough to rise and leak past my seals. I have that little ball check valve and it still dont stop it, I think I need spring loaded unit from 996 TT

[WydRyd]

Candy makes a good recommendation above... do what he says! It's unlikely you have TWO bad turbo's, but you never know

[Maltese Falcon]

SpeedRacer,
if you've run these turbos for awhile with the "Lazy" oil return problem you could have saturated the compressor (oring) seal and the turbine (ring or carbon) seal to the point where they are failing . This really won't allow you to determine if your other remedies are correcting the original oiling up problem.
I would send the units out for re-sealing (not expensive ), any turbo rebuilder of Garretts can do it.
Are your Garretts dry style or wet style ? Only dry turbos should be used on an air cooled engine, as the wets are designed to carry coolant thru them. A Garrett engr @ SEMA explained to me that a wet style turbo will eventually fail if run w/o coolant.
On the oil drains, I've only used #12 for the past 30 years w/o problems. Gravity drain into any available valve cover, chain cover ( circa BAE style) and even the case -- I've done this with xlnt success. What you need to avoid is draining into the oil level--you need to be slightly higher than the oil level.
Positive displacement 12V pumps work OK, but fail when people leave them running w/o any oil running thru them, such as key on / engine off.
Don't give up !
Marty

[speeed racr]

The turbos are brand new. They only have about 15-20 min of run time on them. I am running oil through the water passage.

[Maltese Falcon]

Speed, that may be your problem. The coolant chamber is not designed for oil. The Garrett eng'r told me to run a seperate coolant tank, pump, lines and pressure cap , if I was going to put their wet turbo on an air cooled.
That's why I use turbonetics dry style , ceramic BB turbos--I didn't want to carry all of the coolant accessories.
You may want to contact tech at Garrett and figure it out .
They are in Torrance CA.
Marty