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Mon Oct 12, 2009 6:27 am

Over last winter I replaced the 2332 VW Turbo motor with a 2.5 Subaru Turbo motor in my offroad car. It does not spool up until 4000 or so RPM in 2nd gear and does not build Boost much above 2 to 3#. On the VW motor this same Turbo T-3 60 Trim would Spool up at 2500 and go to 8# (wastegate setting) quickly. The waste gate is working etc. The differences between the VW setup and the Subaru setup is longer exhaust pipes (same diameter) up to the Turbo. The rear cylinder pipes are aprox. 3.5' long and the front cylinders are Aprox. 2' long. The VW pipes are probably a foot shorter on the rear cylinders. Also larger diameter intake track tubing (From 2" ID to 2.75"ID). My theory is the longer Exhaust is loosing way too much heat and velocity pressure to spin the Turbine. Also the 2.75" Intake track tubing has a lot more volume than the 2" to build pressure quickly. How much difference would heat tape make on the exhaust side? Any thoughts

Mon Oct 12, 2009 7:32 am

wow, i would think the larger subaru motor, would cause it to spool faster. did you use the turbo from the VW motor on the subaru, or was it a different turbo, just the same model?

i would check for exhaust leaks, and double check the wastegate, make sure it is adjusted right, and that its not stuck open or anything. just a thought.

Mon Oct 12, 2009 8:54 am

Its the same Turbo. No leaks and wastegate is tight.

Tue Oct 13, 2009 12:19 pm

Some additional Info. I do not see any Indications of Exhaust leaks, ie; no carbon streaks at flanges etc. I used all Copper gaskets. The Blast gate appears to be tight. I would think I would hear it if it was leaking enough to not build Boost. It also worked fine on the VW motor. The Intake tract is made up of aluminum tubing with silicone fittings and "T" band clamps. The BOV only releases when I get out of the throttle and you definatly hear it when it does. Here is a link to the motor swap to get a better Ideal on what I have done. http://www.woodsbuggy.com/index.php?option=com_jfu...amp;t=6013

Tue Oct 13, 2009 1:06 pm

You say the BOV releases when you get off the throttle, which means that it is building boost up to the BOV relief pressure right?

Tue Oct 13, 2009 1:45 pm

I think you are confusing the BOV (Intake Track) with the Blastgate (Exhaust Track)

. takotruckin wrote: You say the BOV releases when you get off the throttle, which means that it is building boost up to the BOV relief pressure right?

Tue Oct 13, 2009 1:57 pm

Sorry, I guess i was mistaken on BOV operation.

Tue Oct 13, 2009 2:01 pm

Blow off valves should release when the throttle slams shut so the boost pressure doesnt hurt the turbo impeller, you shouldnt hear it at all unless you have an abrupt throttle closure.

Wed Oct 14, 2009 5:15 am

Thats when mine releases, during abrupt throttle closures.

baja5 wrote: Blow off valves should release when the throttle slams shut so the boost pressure doesnt hurt the turbo impeller, you shouldnt hear it at all unless you have an abrupt throttle closure.

Wed Oct 14, 2009 6:13 am

Sounds like that part is working then, can you manually keep the wastegate closed and see what kind of boost it builds then?

Wed Oct 14, 2009 6:23 am

I could remove the Boost control line or put a blank off plate on the discharge. If that turns out to be the problem and it builds to much Boost I risk blowing the motor above 8 psi. I may just try to adjust the Blast gate up higher to 12 psi and that should keep it closed for the test. Keep in mind that the Blast gate worked just fine when I took it off the VW and put it right on the Subie.

baja5 wrote: Sounds like that part is working then, can you manually keep the wastegate closed and see what kind of boost it builds then?

Wed Oct 14, 2009 1:17 pm

Where do you have the vacuum line from the BOV connected to? Where do you have the vacuum line from the wastegate connected to? Does the exhaust flange after the turbo block the turbo's built in wastegate?
--Tim

Wed Oct 14, 2009 1:30 pm

The BOV line is connected in the Intake tract between the throttle body and the motor. The Blast gate line is connected on the discharge side of the Inner cooler before the throttle body. The blast gate is external. Keeo in mind this system worked great on the VW motor so the mechanics have not changed much.

Wed Oct 14, 2009 2:03 pm

Odyknuck wrote: The BOV line is connected in the Intake tract between the throttle body and the motor. The Blast gate line is connected on the discharge side of the Inner cooler before the throttle body. The blast gate is external. Keeo in mind this system worked great on the VW motor so the mechanics have not changed much.

Well that sounds correct to me. BOV to intake manifold and wastegate connected to the tube between the compressor outlet and the throttle body.

Is the spring in the wastegate really light? You are running low enough boost that I don't think you would be pushing the wastegate open with too much exhaust pressure, but ya never know.

I'd try disconnecting the vacuum line to the wastegate. You may not see much more boost with it disconnected since you are not getting much boost right now, unless you suspect it is the wastegate and nothing else. If the spring really is too light, you may still push the gate open with exhaust pressure.

Your muffler isn't clogged is it? I just have to ask as my buddy was chasing a low boost problem a few weeks ago and that's what it turned out to be. He eventually saw the fiberglass sticking out of the tailpipe.

--Tim

Thu Oct 15, 2009 7:20 am

TIMMA wrote: Odyknuck wrote: The BOV line is connected in the Intake tract between the throttle body and the motor. The Blast gate line is connected on the discharge side of the Inner cooler before the throttle body. The blast gate is external. Keeo in mind this system worked great on the VW motor so the mechanics have not changed much.

Well that sounds correct to me. BOV to intake manifold and wastegate connected to the tube between the compressor outlet and the throttle body.

Is the spring in the wastegate really light? You are running low enough boost that I don't think you would be pushing the wastegate open with too much exhaust pressure, but ya never know.
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It worked fine on the VW motor so I dont thing its the problem
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I'd try disconnecting the vacuum line to the wastegate. You may not see much more boost with it disconnected since you are not getting much boost right now, unless you suspect it is the wastegate and nothing else. If the spring really is too light, you may still push the gate open with exhaust pressure.
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I will try that.
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Your muffler isn't clogged is it? I just have to ask as my buddy was chasing a low boost problem a few weeks ago and that's what it turned out to be. He eventually saw the fiberglass sticking out of the tailpipe.
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The whole exhaust including the thru hole silencer is aprox 3' long and is open.

--Tim

Thu Oct 15, 2009 12:52 pm

This is a head-scratcher. You don't still have the original PCV line from the intake manifold to the crankcase hooked up, right? Like you're not blowing boost into the crankcase and having it escape through the breather filter. Don't be offended by that, but I have seen some crazy things done before.

My thinking on the wastegate spring was that it could have been strong enough for the smaller VW engine, but too weak for the bigger Suby. Not too much displacement difference though, but I'm sure that Suby can move a lot more air. This is probably not your problem, but I was throwing it out there anyways.

I'm running out of ideas, but it's probably going to turn out to be something simple. :?

--Tim

Thu Oct 15, 2009 1:05 pm

TIMMA wrote: This is a head-scratcher. You don't still have the original PCV line from the intake manifold to the crankcase hooked up, right? Like you're not blowing boost into the crankcase and having it escape through the breather filter. Don't be offended by that, but I have seen some crazy things done before.
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Not offended at all. I am running out of ideals so thats why I put it out there. Hell even a badly tunned motor will build boost better than this lol. As far as the PCV, It is no longer in the picture. I currently have my heads and crankcase "T"ed together and connected to a High dollar Peterson crankcase pressure relief valve via a 2' long 1 1/4" ID clear braided hose so I can see how much oil is getting blown by. So far not a drop of oil in the clear line so Idought I am getting much blow by on the rings. Of cource without much Boost that remains to be seen. The dry sump oil tank also has a Morroso breather/catch tank on it. Now it does get oil in the catch tank. I am thinking its really where the engine is venting at or just because it is the oil tank.. I do have to empty the tank.
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My thinking on the wastegate spring was that it could have been strong enough for the smaller VW engine, but too weak for the bigger Suby. Not too much displacement difference though, but I'm sure that Suby can move a lot more air. This is probably not your problem, but I was throwing it out there anyways.
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Well I dought I have any leaks in the plumbing. I am very meticulas about things like that. So its either gotta be the cheap ass BOV or the waste gate. So I will take them out of the picture one at a time and see what happens.

I'm running out of ideas, but it's probably going to turn out to be something simple. :?

--Tim

Fri Oct 16, 2009 8:13 pm

hmm. didn't see you mention this, but have you tried spinning the turbo by hand? does it spin freely still? any binding at all? perhaps when you swapped everything over, a piece of junk may have made its way into the line, getting caught in the oil line restrictor, blocking off oil to the turbo (permanently or temporary), and might have caused some damage. Just a guess.

If anything check to make sure the turbo is still spinning freely. perhaps something foregin got caust in the turbine slowing it down (old gasket, piece of rubber, etc.). Now this has happened to me. i dropped a tine piece (a small chunk, a little smaller then a pencil eraser) of fuel hose down the carb, and it got stuck in the compressor side, and noticed it was only giving me 2 lbs of boost, versus 8. it got jammed in between the fins and was dragging inside the turbine (big rubber skid mark formed on the inside, lol).

Thats all i got for now, lol. the only other thing i can possibly think of is a gasket. perhaps a gasket got torn upon installation, or a clamp didn't get tightened correctly on one of the intake boots?

other then that, i got nothin :lol:

Fri Oct 16, 2009 9:34 pm

Fuel pressure ok? My turbo runs like crap when the filter gets dirty and the fuel pressure is just slightly restricted. .....Just a stab in the dark.

Sat Oct 17, 2009 3:18 am

BugMan114 wrote: hmm. didn't see you mention this, but have you tried spinning the turbo by hand? does it spin freely still? any binding at all? perhaps when you swapped everything over, a piece of junk may have made its way into the line, getting caught in the oil line restrictor, blocking off oil to the turbo (permanently or temporary), and might have caused some damage. Just a guess.

If anything check to make sure the turbo is still spinning freely. perhaps something foregin got caust in the turbine slowing it down (old gasket, piece of rubber, etc.). Now this has happened to me. i dropped a tine piece (a small chunk, a little smaller then a pencil eraser) of fuel hose down the carb, and it got stuck in the compressor side, and noticed it was only giving me 2 lbs of boost, versus 8. it got jammed in between the fins and was dragging inside the turbine (big rubber skid mark formed on the inside, lol).

Thats all i got for now, lol. the only other thing i can possibly think of is a gasket. perhaps a gasket got torn upon installation, or a clamp didn't get tightened correctly on one of the intake boots?

other then that, i got nothin :lol:

I have checked for fee spin several time and its allways been good. I actually replaced the entire center section over the winter with a brand new one twice. when I first put the turbo on this motor it would pruke oil out the exhaust. I replaced it again and thats when I added the supply line restrictor and solved the problem. The dry sump system produces 75 psi oil cold and 50 hot.