924Board.org

Racing · Joined: 27 Apr 2004 Posts: 374

Could i ask you to be more specific?
Amount of boost?
Intercooler?
What turbo?
Intake OEM?

asf.

jl924t · Joined: 03 Nov 2002 Posts: 214 Location: Surrey, BC Canada

Compression is; from 1-4, 155 150 145 150. Test done dry. I should explain regarding the fuel consumption that I seldom let it get below 1/4 tank.
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1980 924 turbo

Paul · Posted: Sun May 02, 2004 11:28 pm Post subject:

Great numbers! How much boost are you running, tell us more?

jl924t · Joined: 03 Nov 2002 Posts: 214 Location: Surrey, BC Canada

Every thing is stock except for the pistons.I bought the block from International Motor Shop in Plainview NY (ebay) for $400.00. I got a bored block (87.5mm), connecing rods & polished crank. While talking to Joe about the block I decided to let him fit the pistons and connecting rod bushings. He charged me $350.00 to supply 4 forged pistons, rings, rebush the rods and hone the block. For an additional $53.00 he gave me a new turbo head (less caps and missing 2 valves) and 53 valve guides (std and oversize). He was retiring and cleaning out his excess stuff. He shipped the pieces to me (accross the continent)in 4 boxes by UPS. (cost me another $400.00). When the packages arrived I assembled everything and except for the oil gallery plugs everything went fine. 20 litres of Mobile 15/50 later I was on the road. I figure with gaskets and everything else I spent about $1500.00 for a fresh motor. I did not spend much time putting it all together, basicly bolted it all together and fired it up (3 times before I found the proper oil gallery plugs). In the beginning I had a condensation problem in my oil seperator but that seems to have gone now. Like I said before it runs strong but I do not have any experience in another 931 to know how strong. Maybe at the next BBC I will let Lizard take it for a drive and he can let me know how it compares. My tranny is in need of some maintenance so I don't shift too aggressivly. The problem I have now is not driving it so I can work on it. I do like having a non interference turbo engine though. It gives me peace of mind knowing that if my belt breaks I can coast to a stop and not freak.
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1980 924 turbo

jl924t · Joined: 03 Nov 2002 Posts: 214 Location: Surrey, BC Canada

regarding milage. I filled it up this morning and put in 46.49 litres. I drove, fairly agressivly, 398.6 KM. Works out to roughly 20.13 miles per US gallon or 24.14 miles per Imperial (ROW) gallon. I think.
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1980 924 turbo

Racing · Joined: 27 Apr 2004 Posts: 374

JL.
Point is that the route taken is more or less exactly the one i´ve done-with something completely different in mind.
Performance.
Also run flat tops a fair bit down the bore,and with what seems a somewhat hogged out combustion chamber in the head.
My slugs TDC;s at 5,2mm down the deck of the block.
I hope to be able and boost it inxs of 25psi with the somewhat larger huffer than stock that i got on-and still make it live and prosper.

jl924t · Joined: 03 Nov 2002 Posts: 214 Location: Surrey, BC Canada

I was just scrambling for parts and wanted something I can rely on at a reasonable cost. I had a bad summer last year going through 3 head gaskets, wastegate diaphram, waste gate control line fitting, 2 pistons and a water pump, oh and 3 sets of oil gallery plugs, various sizes(5/8, 16mm, and Porsche). I still have a long way to go to the performance stage. As it is now it is plenty for me, I only open my waste gate in 1st gear sometimes 2nd. I may want more after track day. It will be interesting to watch your progress.
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1980 924 turbo

kye · Posted: Mon May 03, 2004 11:40 am Post subject:

in terms of upping my boost, i've been considering replacing the wastegate spring on my 81' 931 ROW with a 1bar version. a friend says that will take me from about 11pound to 14.2 (if I remember correctly), and from reading various things on the net that seems to be a common upgrade.

with the extra power, are there any issues with the stock driveline that I need to look at? the current driveline seems fine during full-throttle runs in 1st, 2nd and 3rd (haven't gone faster than that!) so i'm assuming it's in good health, although it hasn't been checked over by anyone.

i'd like the extra power, but can't afford to upgrade many parts, and I don't want to break anything!

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it's funny, but when they said "Anything is Possible", that's exactly what they meant....

Racing · Joined: 27 Apr 2004 Posts: 374

kye.
You´re by far safe.No sweat what so ever.

kye · Posted: Mon May 03, 2004 5:41 pm Post subject:

how much boost will the factory setup take before you start to stress things, and what parts are the limiting factors? (apart from your tyres!)
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it's funny, but when they said "Anything is Possible", that's exactly what they meant....

Racing · Joined: 27 Apr 2004 Posts: 374

Kye.
One word.
Pistons.

These will go awol first.
The stock cast 931 ones are REAL garbage,while the stock GTS kolbenschmidt´s will take it a little further.Only real remedy we´ve found is to replace the whole deal with flat tops so far.Jury´s still out on that one tho.Will report findings over time to tell you guys how these hold up.
Apart from that at least i haven´t had any probs with the stock complete head,block,recond rods,crank aso.

Seems the general consensus is to add fuel,install cooler.
After that it´s piston swap time,and after that...well i for one don´t know.
I´d say that as of current i´m pushing realistically around the 350 mark and she keeps together well.
On the other hand we´ve played rather safe than sorry after all the piston probs we´ve had and installed a solid copper head gasket and piston spray cooling this time out.
On the other hand only have had probs with the head gasket twice,and then have in mind that i´m at 25 psi up.

Racing · Joined: 27 Apr 2004 Posts: 374

More direct to your Q tho...
With the stock compressor housing and a cooler 1,1 bars no sweat.
Just make sure you´re ontop when it comes to general tune of engine.
At those 1,1 bars start by setting idle timing @ 4 degrees with hoses to dist connected.