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924RACR · Posted: Thu Sep 04, 2003 11:12 pm Post subject: Turbo update

Latest crap I'm up to with my turbo...

Still have a lingering oil leak... I've isolated it to the joint with the o-ring where the charge tube slips onto the turbo. Oil leaks out of there and onto the outside of the turbo, all over the exhaust, etc. It smokes when this happens, which is mostly only occasionally, except when I take a hard (>0.3g lateral accel) left turn. So I'm not going to be tracking the car anytime soon! LOL

But it's interesting, it only smokes externally, and will even come out from under the hood. Obviously if that happens when I'm moving, the airflow puts the smoke out back. Amusing to cover cars chasing me in a haze of Mobil 1 fumes!

The other major project is the fool pump wiring. I'm still having an occasional aggravation whereby the fuel pump fuse (in fact, the entire aux fuse box) gets hot and I have hesitation - presumably due to loss of some fuel pressure, and car runs lean. It does go away when I'm on boost and it's full rich, and the car when cool is happy. Can correlate it pretty well to the temp of the fuse box, though the source of the heavy current draw could be elsewhere.

So, after a discussion with John Brown, I'm going to run a new wire for the fuel pump - battery to inline fuse to relay, then back to the fuel pump. I'll keep the stock relay (new and good, desired) with all it's activation wiring, but have all new power wiring. I can also later, if desired, add a new power supply to the relay (if the main power re-wire doesn't fix the problem). I'm also going to do it in stages, as you might expect, to try and isolate one side of the circuit if possible. Of course it could just be the whole circuit anyway.

We'll see what happens! In the meantime, I also have to get cracking and paint the other turbo, so I won't be hideously embarrassed to drive it on the street...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

924RACR · Posted: Fri Sep 05, 2003 2:48 am Post subject:

I forgot to add, I do have one area of suspicion WRT the oil leak. There is supposed to be a bracket that secures the lower half of the boost/charge tube to the head. This is missing in my 82, which is the car that leaks. I suspect the motion allowed there bleeds boost and oil equally. I will be pulling it off of my '81 to copy (we have sheetmetal forming facilities here @ work) and will see if that fixes the problem, when I have time to tear both cars apart...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

numbbers · Posted: Fri Sep 05, 2003 10:04 am Post subject:

Well Vaughn, if you are getting oil from the O-ring seal between the upper and lower charge tube, then that oil is coming from the intake side of the turbo. That means the seals are gone, and if you don't rebuild the turbo soon, it will seaze.
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1980 924 Turbo

924 turbo · Posted: Fri Sep 05, 2003 2:54 pm Post subject:

Maybe not. Vaughan mentioned that he gets smoke when taking harder left turns, suggesting that oil is likely escaping past his air-oil separator and pooling in his airbox, and that when he turns hard to the left the oil is pouring into the turbo and being blown into the charge tube, causing the leak.
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Jon Furst

Joes924Racer · Posted: Fri Sep 05, 2003 4:35 pm Post subject:

its messy [Im guessen] since its from the turbo it doesnt leak if its stopped so you dont have to cover the driveway..I had a oil filler cap on the valve cover loose a gasket though im suspecting it may be a worn cover since I switched to a plain one after painting the original..anyway made a double cork gasket
to fit ..fixed it to. almost like staring the car with no oil filler cap
believe it or not..Iknew the head wasnt plugged and filling with oil.

howdy/take care. turbo dudes
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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

924RACR · Posted: Fri Sep 05, 2003 10:58 pm Post subject:

That's what I'm thinking, Jon...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Smoothie · Posted: Sun Sep 07, 2003 5:04 am Post subject:

Interesting. I've had the same small leak from that joint for many years with no apparent smoking out the tailpipe and no noticable oil consumption either. Normally, it's such a slight leak that it doesn't even smoke from burning off of the turbo, but when that o-ring goes bad it leaks enough to produce some smoke. Never could decide on just how the oil was getting there - very interesting that it might be getting in through the intake.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

I'm about at the same point with my fuel pump wiring, if I can't sort it out in the next week with the multimeter, I'm going to wire in a new circuit, with a toggle switch for the fuel pump.

My understanding is, if the engine is off, but the fuel pump is running, it's just going to return all that fuel to the tank, right?

Neil924 · Joined: 18 Mar 2003 Posts: 4225 Location: Canada

Smoothie, is your dog dead?

Kenodog · Joined: 25 Jun 2003 Posts: 2669 Location: Vancouver,B.C.

So after spending all day yesterday with Lizard installing my new 2 stage boost controller it doesn't work!!! Argh. We tried hooking it up to the wastegate line off the intake runner and from a line we ran from the top of the wastegate into the intake runner.The only success was the later but then the 2nd stage effect didn't come on.I can hear the solenoid switching in the control unit but I get no higher boost.And the dials on the control unit were labeled wrong so instead of starting out with minimum boost it was the other way around.WooHoo.That sucker shot up to 10 PSI before I hit 3200 rpm.Yep for $318 Can. i'm not impressed.It's going back to the turbo shop on Mon. to see if the professionals can figure it out.And Vaughn i'm having the exact same problem with my fuel system.Can you or anyone else tell me step by step what I need to do to re-wire the entire system.I've had it, once and for all this POS needs fixin'.I have a '80 931.Tahnks,L
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
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2014 Mazda CX-5 (Kinderwagon)
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Paul · Posted: Sun Sep 07, 2003 11:34 am Post subject:

If I understand how you hooked it up (backwards), of course the knob is going to work backwards...

J1NX3D · Joined: 06 Feb 2003 Posts: 1333 Location: New Zealand

Neil924 · Joined: 18 Mar 2003 Posts: 4225 Location: Canada

I think the pooch chased a ford and was F.O.R.D. and smoothie took him inside to take pictures{wait a minute thats gross} Maybe the dog's hungover? Too much boose and too many hookers for him I guess.

924RACR · Posted: Sun Sep 07, 2003 11:06 pm Post subject:

LOL...

Yes, CBass, you're correct.

My though was to re-wire the power circuit to the pump, but keep the stock relay in there to switch it. I still believe that's working fine, I feel the only problem is the power feed circuit to the pump itself. In further investigation, I feel that it's the old aux fuse panel. I will be retrieving the car today and doing that and swapping the bracket for the charge tube today first thing. (No, the car wasn't broken down, just had to leave it at the office, took another one home, a demo car)

The way the circuit is wired, the fuse panel is "downstream" of the relay. For me it's very clear that that's an obstacle in my car - YMMV! As stated, I plan on dropping the aux fuse panel, removing the fuel pump leads, and connecting them via a crimped-in inline fuse. Will take some creativity, to make sure I don't muck up any other circuits - there are a number of leads there all fed together and piggybacked off of the same sources.

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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Paul · Posted: Sun Sep 07, 2003 11:33 pm Post subject: