924Board.org

AGD931 · Joined: 17 Mar 2003 Posts: 289 Location: Athens, Greece

Well, February was an eventful month for the 931....
First the WUR packed up, could only get a new one from the States (thanks John at Special T auto, excellent service

), the WUR is fitted and I then break down on the way home from the workshop

Cause, a split intake boot between the fuel distributor and the turbo AND the round seal at the bottom of the charge tube to the turbo.

Got all this lot fixed... phew! All basic settings, CO, idle etc were reset, the engine now purrs like a kitten, and is very smooth and driveabiity is excellent. Torque is also better low down and a stumble that I had for years when accelerating from low speed in high gear has disappeared.

I have never had the engine working this good, only thing is amongst all this euphoria and happiness, I seem to have lost, or at least it has been tempered, that wild kick as the boost comes on. Road speed witnessed via the speedo builds up alright but it is all done so smoothly and without fuss that I am wondering if something turbo related has packed up. To be honest, I am not sure if the car is finally working as it should be or I am just being paranoid about the turbo finally going.

Then again, I am thinking, the WUR is new, fuel pressures, CO are what they should be, maybe it should be like this....

Arthur
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1981 931 S2
1990 E30 320i Cabrio
1979 Ford Capri Ghia

Smoothie · Posted: Tue Mar 13, 2007 8:06 am Post subject:

I've never really noticed a "wild kick" as boost comes on. It's always been more of a steady transition - then if/when I have the boost turned up with the WG control line valve it gives a nice little plaster you back in the seat feeling, but even then not what I'd call a "kick". I'd guess you had something wrong before that got fixed, so what you had was poor running followed by things "kicking in" or coming together at a certain engine speed. In other words, the kick may have just been a sudden transition from engine hesitation to normal running.
Early articles from the time that the 924T was introduced mentioned how "refined" the turbo response was compared to other turbo cars.
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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

924RACR · Posted: Tue Mar 13, 2007 10:08 pm Post subject:

I'm with Smoothie... mine used to kick harder before I got all my vacuum leaks fixed, as it wasn't running well off-boost. Now the pull (torque curve) is smoother...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

AGD931 · Joined: 17 Mar 2003 Posts: 289 Location: Athens, Greece

Thanks for the comments guys,

I have to say that I agree with you, getting used to it now.

Arthur
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1981 931 S2
1990 E30 320i Cabrio
1979 Ford Capri Ghia

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

That's a gorgeous car, Arthur. . .I love the paint job. Have you got a bigger pic?
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

AGD931 · Joined: 17 Mar 2003 Posts: 289 Location: Athens, Greece

Thanks for your kind words

Always happy to oblige

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1981 931 S2
1990 E30 320i Cabrio
1979 Ford Capri Ghia

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Somebody needs Photoshop for their birthday this year. . .

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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

Out of all the 931's I've seen, I still like this color combo the best.

After all, it's the two FASTEST colors made by Porsche.
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'80 924 n/a SOLD

AGD931 · Joined: 17 Mar 2003 Posts: 289 Location: Athens, Greece

Thanks for your comments on the paint job, I too think its great, very distinctive, really suits the lines of the car.

On to business.........

Well.... February has now gone into April!!!!!

From my first post, I said that I had replaced the round seal between the turbo and the lower charge tube. Well, that replacement somehow cut itself into two pieces and of course left me stranded as the lower charge tube came off the turbo. The mechanic replaced it yesterday, I took the car out today for a drive to clear out the cobwebs, everything fine. Went home to give the car a well earned wash, looked down by the turbo (pushing my luck) and found the seal hanging out again!!!!!!!

I removed the upper charge tube to see what the heck had happened again and lo and behold I think I found it. On reinstallation I discovered what can be seen in the two pics that follow. The charge tube mounting and bolt will not line up with the intake manifold. I am suspecting that the mechanic was first bolting the charge tube to the intake manifold then to the lower charge tube and straining the seal because..... (and this is where you guys come in with comments) I think that the engine mounts have gone and the engine has leaned over to the left.

Question is now, am I right? Are the mounts gone or will this run into May?

(sorry about the quality of the pics, they are from the phone - 2 megapixels my a**!!)

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1981 931 S2
1990 E30 320i Cabrio
1979 Ford Capri Ghia

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

Have you had your turbo rebuilt recently? That misalignment looks like it's from the cold side housing not being clocked correctly. Motor mounts wouldn't effect it.

ps - I love that color combo too

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1980 931S
15psi boost, MS-II, EDIS, 951 IC, custom intake, Ford 5.0L throttle body, Forge BOV, WB o2, G31 w/LSD, 964 wheels, 968 rear sway, Bilsteins, 200# Welt. springs. A laptop, and a partridge in a pear tree.
1991 964 C4 Cabriolet

AGD931 · Joined: 17 Mar 2003 Posts: 289 Location: Athens, Greece

No, I have not touched the turbo sinceI bought the car in September 2001.

The exhaust manifold was blowing about this time last year, the studs were replaced and the blowing was fixed but the turbo was not removed.

Can you elaborate what you mean by the cold side housing not being clocked correctly?
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1981 931 S2
1990 E30 320i Cabrio
1979 Ford Capri Ghia

Smoothie · Posted: Mon Apr 02, 2007 3:02 am Post subject:

AGD931 · Joined: 17 Mar 2003 Posts: 289 Location: Athens, Greece

Smoothie, what can I say? Thanks mate!

When I removed the lower charge tube I did notice that the bolt hole had nothing attached..... I have a bracket on the block but it appears to need a long bolt in order to attach to the charge tube

Following your post, I checked PET and I think the bracket I have is not the same. From PET it appears that the bracket sits flush on the lower charge tube. My bracket is at least 2cm away from the lower charge tube.
If it is supposed to be flush, I will order a new one with the required bolts and hope that is the end of the saga

I understand now how to bolt the charge tube, but doesn't pushing so hard on the charge tube to line up the holes put a strain on the lower charge tube, or is this where my "bracket" comes into play?
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1981 931 S2
1990 E30 320i Cabrio
1979 Ford Capri Ghia

924RACR · Posted: Mon Apr 02, 2007 4:11 am Post subject:

Is it possible you have the right bracket bolted into the wrong place??
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Smoothie · Posted: Mon Apr 02, 2007 4:14 am Post subject:

I'd doubt that you have a wrong bracket there. There is some degree of adjustability to where it attaches to the block - though not a full 2cm.. Here're pics, a drawing and measurements of the OE bracket -
http://www.924board.org/viewtopic.php?t=11372

Does your turbos' cold side rotate at all? On mine, all of the perimeter bolts are tight, but it stills rotates some - I suspect they're all like this or get this way over time.
Don't worry about strain on the lower pipe. As long as it's bolted to the upper pipe and the cold side can rotate some, it should all go together with some force. It's just not an assembly that slips together easily.
_________________
"..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