924Board.org

claydoc · Joined: 24 Oct 2004 Posts: 17 Location: Austrialia

Hi Guys I have got my self an 1981 931, great little car. Sold my 1968 911 for it. My 931 has only 97,000 km's (60,000 miles) on it and is in great condition for a 23 year old car. I installed a VDO boot guage today and connected to the inlet tube before the throttle body and I get 10 PSI from 2800 RPM to 6000 RPM. Why don't your US cars get this from a stock setup? (Mines stock) Also I'm a little confised about checking the timing and what degs it should be... I'm in Australia so I'm not sure what degs it should be. Hayes manual is all about US and UK models.

Any help / thoughs would be great.. and if i can help with anything please drop me an email mate...

Regs Chris[/img]
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924guy · Posted: Mon Oct 25, 2004 12:36 am Post subject:

the 81 factory suppliment shows ROW cars should be set at 8-14 BTDC, so you have a 6 degree adjustment range to play with and find where yours likes it best.. (same for 82's btw, and USA versions are 6-10 BTDC.)
after setting the base timing the DITC will take over and make its own adjustments due the needs of your engine..
my usa 82 will boost at up to 14psi under wot, unmodified so far as i know..
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Smoothie · Posted: Mon Oct 25, 2004 1:20 am Post subject:

If you have digital ignition timing control (DITC), you can't actually set the timing. It's taken care of for you. Turning the distributor as you would on a "normal" car has no effect on timing with DITC. The distributor only directs the spark to the correct plug in sequence and has to be positioned correctly to "catch" the spark and direct it at whatever point in time the DITC decides to send it. There's a procedure that involves adjusting the idle speed while using a timing light on the flywheel, but that's done because DITC uses electronic idle speed control - it adjusts your idle speed (up for instance when the AC is switched on) by altering the timing (advancing it to speed up), so when the idle speed adjustment at the throttle is set correctly, the timing mark (an "O" mark on US cars) lines up in the flywheel window.
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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

Khal · Posted: Mon Oct 25, 2004 8:54 am Post subject:

Another Aussie! We're taking over!

G'day claydoc. Just FYI, check out this thread by kye (another Aussie) who recently had his stock '81 924 Turbo dyno tested -he was pushing ~10psi or over from ~4,000rpm. But only ~3psi at 3,000rpm?

Welcome to the 'board. Enjoy!

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'80 924 Turbo

Paul · Posted: Mon Oct 25, 2004 10:08 am Post subject:

US cars have a 7 PSI spring in their wastegates, the ROW cars have a 10 PSI spring.

I NEED A 10 PSI SPRING, please send me one, $$$$ waiting!

claydoc · Joined: 24 Oct 2004 Posts: 17 Location: Austrialia

Thanks for the info guy's all very helpful, My new VDO boot guage builds up from about 2,000 RPM and hits 10 psi at 2800 RPM thru to 6,000 RPM.

Ok the DITC sets the timing, but how do you know how to set the correct position of distributor? moving the distributor small amounts seems to makes no diffrence to how the car idle's untill you turn it alot and them then it will idle rough.

Yes another Aussie.

Thanks,

Regs Chris
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Paul · Posted: Mon Oct 25, 2004 12:42 pm Post subject:

Turn it one way until it stumbles, then the other way until it stumbles, then put it in the middle.

Or set the cam with the dot on the pointer then make sure the distributor rotor is pointing to the notch in the distributor housing.

The picture below is a Series 1 distributor, but yours should have the same mark, but no wiring connector and other parts.

Smoothie · Posted: Mon Oct 25, 2004 1:16 pm Post subject:

The post for plug #1 should be aimed toward the rear-left of the car. With timing marks on the back of the cam wheel and on the flywheel at TDC, the rotor should point at that #1 post. Firing order is 1-3-4-2 and the rotor spins clockwise as viewed from above, so #3 is toward the front-left, #4 is front-right and #2 is rear-right. This should leave the dist cap clips lined-up roughly front-to-back. Now make sure the clips line-up straight front-to-back of the engine*. With that, it's oriented correctly so that spark will get to the correct cylinder and at whatever advance or retard the DITC "decides" on.

There's a photo showing it on pg 290 of the Haynes Porsche 924 and Turbo book (#397 US) - (maybe on a different page in the OZ version).

* - If the rotor is no longer aimed straight at post #1 at this point, then the distributor must have been removed, then not dropped back in at exactly the same orientation as it was from the factory. In that case, you can't just line-up the clips straight front-back - you'd either remove and re-orient the distributor or just turn it so the rotor points straight at the notch that's cut in the top edge of the distributor (which should correspond to post #1).
_________________
"..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

claydoc · Joined: 24 Oct 2004 Posts: 17 Location: Austrialia

Thanks for this dude... will check it out tonight.

Regs Chris
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Go racing .. It's fun!

claydoc · Joined: 24 Oct 2004 Posts: 17 Location: Austrialia

Thanks again guy's this now all sorted, lined up the rotor with mark on the dizzy, all looking good now.

Thanks for you comments and info

Regs Chris

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Go racing .. It's fun!

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

Chris

I don't think anyone mentioned, as far as Haynes and Porsche are concerned Australian and UK cars are the same.

The only difference is that the paint on the Aus cars fades faster

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kye · Posted: Tue Oct 26, 2004 5:21 pm Post subject:

full boost at 2800RPM.. wow! you can see the dyno results from mine, getting to max boost about 4000. any ideas about what's different?

It had new oil in it when it got tested, although it was a 10/50 (I think.. memory being a bit fuzzy) which i'm told might be a bit heavy to get max performance..
or you've got a smaller turbo to spin up or some mods perhaps?

any secrets to get me full boost by 2800 are more than welcome!!!!

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Carris · Posted: Tue Oct 26, 2004 5:35 pm Post subject:

By the pressure guage on my car I am getting max boost at about 2800~3000 RPM. Not sure exactly what spec my car is or if it is modified, just thought I'd chip in.
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Chris

claydoc · Joined: 24 Oct 2004 Posts: 17 Location: Austrialia

Hi Kye,

My boot guage starts to move at 2000 RPM and then hits 10 psi at 2800 RPM. My Car is stock with STD K26 KKK turbo. Not sure why yours only hits 10 psi @ 4000 RPM's? How many Km's on the clock?

Regs Chris
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Go racing .. It's fun!

kye · Posted: Wed Oct 27, 2004 11:11 am Post subject:

mine has about 107,000kms on the clock (good estimate - recently broken odo)..

my boost starts climbing at 2000 too.. this whole thing is food for thought.
I think that one of you guys should get your car dyno'd and we can see if maybe mine is lagging behind in building boost, and not the norm, as i'd assumed!

although with mine not showing any signs of anything being 'broken', i'm beginning to think maybe your performance could be related to mods, or maybe much newer parts?
can anyone there give me the date of your last turbo recon? I can look at the plate on mine and we can see how worn these things should be..
maybe my bearings are towards the end of their lifespan..
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it's funny, but when they said "Anything is Possible", that's exactly what they meant....