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General => The garage => Topic started by: stew8vmk2golf on 14 August 2003, 11:22
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any one help me at all. Im looking at turbocharging my mk2 gti, its a 1990 8v digifant, i was wondering if anyone knows any companies which do a conversion for my car or if its possible to fit the manifold and turbocharger from a TD. I have been told that the air flow meter will work ok and that the current digifant II ecu would also work ok. This may sound a stupid question but are the manifold shapes different on an 8v and 16v??
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Have turbo on my mk1 gti. Did the turbo diesel conversion. Get yourself a exhaust manifold and turbo off a diesel, turn manifold upside down and fit it to the engine (some grinding required tho fit). Loosen the bolts on the compressor housing and rotate it to face in the direction needed. The rest is easy enough, oil supply and return,inlet pipework, etc. You will have to make up your own down pipe. Recomend you use a intercooler, I am running at 9 psi boost on standard comps, had some pinking but have overcome that. Clutch has started to slip now :(, ahh well, the 2 ltr 16v turbo project has just been brought forward ;).
PS. My conversion was on a mk1, not sure about clearance issues with the rear engine mount on a mk2. This is a good junk yard turbo project, dont think you could turbo a car and get so much for so little ???s. Good luck, Steve.
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what about the fueling, what is the best way to sort this, as when running boost the air flow meter wont recognise such high pressure will it???
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I use a pressure switch to fire the cold start injector. With your digifant, you could trick the ECU inputs from the coolant temp sensor, or alter the fuel pressure to the injectors when on boost. Steve.
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so i could actually run a turbo on my car without changing the ecu or the airflow meter? how would i alter the fuel pressure when its on boost???
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Well, you could fit a pressure regulator that can "see" the manifold pressure increase and restrict the tank return from the rail to increase the amount of fuel injected for the same injector dwell time.
My conversion was on a K jet, so anyone feel free to advise for a digi set up. Good luck, Steve. ;)
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interesting stuff MK1. I'd be interested to know how the 2 litre Gets on when its done. I always thought that when turbo charging you have to fit a thicker head gaket or a spacer to lower the compression ratio so that your not gonna blow anything.
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I am lowering the compression ratio by machining the top of the pistons as fitting a spacer or two head gaskets will alter the cam timing. You can run with standard compression as long as you run low boost and intercooler and moniter fuel ratio. My set up seems ok at around 9psi, with standard comps, but I have had to make some mods to stop pinking.
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if i was to fit a g60 ecu what would i need to add to the current loom? I know i'd need to wire in a lambda probe, is there anything else?
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"Well, you could fit a pressure regulator that can "see" the manifold pressure increase and restrict the tank return from the rail to increase the amount of fuel injected for the same injector dwell time."
So how would that work? Where could i get one of these from and how would it wire up?
Is there any one with an idea of how I could set this sort of thing up on a digifant II setup?
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Its a "rising rate" fuel pressure regulator, senses the manifold pressure and adjusts the fuel pressure to match the increase. G60 is the way to go if you have all the parts. Keep us posted, am interested in your project. My 16V engine is now built and the turbo is on its way ;D, Steve.
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interesting stuff MK1. I'd be interested to know how the 2 litre Gets on when its done. I always thought that when turbo charging you have to fit a thicker head gaket or a spacer to lower the compression ratio so that your not gonna blow/quote] you could take out your conrods and have a machine shop knock up some offset small end bushes this will lower the pistons and effectively lower the compression.this will retain the strength in the piston crown where you need it most on a turbo engine
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Agree that the small end mod is a more stable way to go, but I looked at the the bearing and 2mm would not leave a lot of bearing, so the piston it was ;). Will let you know if I was wrong ::). Steve :)
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Machining bits off sounds a bit iffy?
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The pistons have been machined by the factory to clear the valves, so I saw no problem taking some off the crown to lower the compression. I know that forged pistons are the way to go, but I want to keep the cost realistic. If it goes well and melts a piston, a set of forged pistons will go in. The small end bush is also under a lot of load when boosted, what would you do?. I am using what I have, and the resources availible. ;). Will keep posting progress for those who are interested, and if anyone has any ideas, please add to this thread :). Steve.
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I would put a thicker head gasket in and some decent pistons. Otherwise its bound to go bang sooner or later, probably sooner ;) Good Luck :D
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Thicker head gasket would mean vernier pulley, pistons may come yet ;). Will post as I go. Steve
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I would think thicker head gasket would be essential to stop it going BANG! :o What engine you putting a turbo on, 9A?
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How is this going? I have a 1990 Mk2 8v and am VERY interested in this. Please let me know.
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Check the mk1 golf forum, have posted in there. The car is up and running, goes :o, .
Steve
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Yeah, it looks good mate :o what did you lower the compression ratio to ?
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They are at 8.75 to 1.
Steve.