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Copper head gasket again

 
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cgoldhill  



Joined: 25 Sep 2004
Posts: 28

PostPosted: Mon Sep 27, 2004 1:46 am    Post subject: Copper head gasket again Reply with quote

I thought i had posted this but i can't seem to find it. Anyways, if i were to run 16 pounds of boost in a 924 turbo would i need to o-ring the block and use a copper head gasket or would it be safe to jsut use a copper head gasket? Also, if i plan on running this high of boost is it necessary for efi?
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numbbers  



Joined: 05 Nov 2002
Posts: 1910
Location: Highlands Ranch, Colorado

PostPosted: Tue Sep 28, 2004 11:07 am    Post subject: Reply with quote

Where are you located? What altitude? I run 17 PSI with no problems in the Denver area, using the factory head gasket. The headgasket won't be your problem, detonation will.
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cgoldhill  



Joined: 25 Sep 2004
Posts: 28

PostPosted: Tue Sep 28, 2004 11:37 am    Post subject: Reply with quote

i'm located in southern new jersey which i believe is close to sea level. Wow i'm didn't know the head gasket on these things were that strong. What do you need to do to these cars to prevent detonation at this high of boost levels? Is efi necessary or can i just use an adjustable fuel pressure regulator and higher flow injectors to prevent this detonation?
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mick  



Joined: 13 Jun 2003
Posts: 183
Location: ohio

PostPosted: Tue Sep 28, 2004 1:19 pm    Post subject: Reply with quote

i have that same question how can i stop detonation in my 80 931?? i think thats what blew my ring on #1 and #3. im at 1 bar with a top mount ic also i just put in a msd 6 complete kit. which i think was burning to much gas out cause of the 10 degree past spark
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80 931 intercooled,1 bar, and kinda runs right
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sandgroper  



Joined: 07 Dec 2002
Posts: 95
Location: in limbo

PostPosted: Tue Sep 28, 2004 3:58 pm    Post subject: Reply with quote

Every 80 engine i have dismantled had broken rings,i have decided and scored at pickapart 3 87-89 pontiac sunbird turbo delco ecu,that car had boost control,anti knock etc,same ecu but different memcal gm used it in the typhoon and cyclone,a turbo v6 4x4,it also controls peak and hold injectors.the typhoon guys have got a program for that ecu thats a free download,in fact their is a couple of programs for that ecu.just need to spend half a day pulling a harness and probably a month to install neatly using new cheap as gm sensors,oh yeh its good for 2 bar map sensors as well.Should be a major improvement over cis.
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jazz guy  



Joined: 26 Nov 2002
Posts: 391
Location: Colorado

PostPosted: Wed Sep 29, 2004 6:09 am    Post subject: Reply with quote

In my experience, the stock headgasket has been quite reliable. I have a boost controller on my '82 931 and have run 12-14 lb. boost regularly for more than ten years with no (knock on wood) headgasket problems. As nummbers indicated, I think you will find detonation to be the big problem as you raise the boost level. Like numbbers, I live in Colorado (north of Denver), but I have never been able to run boost in 17psi range without some good octane booster and a cool day. I can say though, that things really do start to get fun when you get into the 16+ psi boost levels.
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numbbers  



Joined: 05 Nov 2002
Posts: 1910
Location: Highlands Ranch, Colorado

PostPosted: Wed Sep 29, 2004 10:36 am    Post subject: Reply with quote

My advice, just work your boost up slowly, until you start to get some detonation. Then back it off, at least 2 psi as a safety factor. Then go have fun if a fast old Porsche.
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Kenodog  



Joined: 25 Jun 2003
Posts: 2580
Location: Vancouver,B.C.

PostPosted: Thu Sep 30, 2004 1:39 pm    Post subject: Reply with quote

My advice is DONT run till you hear detonation.By the time your ear can hear it,and all of us hear different octaves differently,you will already be doing damage to your engine.To do it properly save some cash and buy yourself a good MSD set up.The one MSD suggests is a 6420 BTM iirc.These can be had on ebay for around $2-300.It comes with an in cockpit adjustable retard dial and you can hook an MSD knock sensor to it as well.Better idle,the benefit of more top end power and no engine damage,worth it to you?
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cgoldhill  



Joined: 25 Sep 2004
Posts: 28

PostPosted: Fri Oct 01, 2004 7:36 am    Post subject: Reply with quote

What can do to eliminate detonation besides use an intercooler? Also, what intercooler is good for 17 psi? The top mounted intercooler or the 951 one? are either of these good enough?
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Paul  



Joined: 02 Nov 2002
Posts: 9414
Location: Southeast Wisconsin

PostPosted: Fri Oct 01, 2004 9:33 am    Post subject: Reply with quote

Higher octane gasoline will help. You can buy cans of octane boost at most auto parts stores and some tracks have high octane lead free.
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Smoothie  



Joined: 01 Jan 2003
Posts: 8030
Location: DE (the one near MD, PA, NJ)

PostPosted: Fri Oct 01, 2004 10:35 am    Post subject: Reply with quote

Some other tricks to postpone detonation are to retard the ignition and/or to richen the air:fuel, but your car should be doing both of those already to some extent. There's also water injection and/or using higher octane fuel as Paul mentioned.
Which series 931 do you have anyway? (ser.1 = '79-'80, ser.2 = '81-up)
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'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox
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cgoldhill  



Joined: 25 Sep 2004
Posts: 28

PostPosted: Fri Oct 01, 2004 11:47 pm    Post subject: Reply with quote

I will be purchasing an 81 or 82 as soon as i can find one in my area. If anyone knows of one being sold within 100 miles of Southern New Jersey, please pm with details. I notice that you live in jersey, where at?

Thanks guys for all the good info!
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Smoothie  



Joined: 01 Jan 2003
Posts: 8030
Location: DE (the one near MD, PA, NJ)

PostPosted: Sat Oct 02, 2004 3:03 am    Post subject: Reply with quote

Central NJ, next to New Brunswick.
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'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox
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Raceboy  



Joined: 01 Mar 2004
Posts: 2318
Location: Estonia, Europe

PostPosted: Sat Oct 23, 2004 6:07 pm    Post subject: Reply with quote

ok, to the topic , Question: does anyone have CAD file of the copper head gasket (in order to make one) ? And, does anyone, exept Racing, use CU head gasket at present time?
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