924Board.org

931 twinturbo · Joined: 20 Jun 2007 Posts: 122 Location: Norway

That´s right BassGT....

But if you se at the Freisinger engine, is it 2 turbos on that engine????? One left top of the engine and one down to the right??? nOr one kompressor and one turbo???
check the link

http://www.freisinger-motorsport.de/porsche/uk/Porsche_Restoration_Detail/8.html
_________________
911 Targa 1974 Turbolook/Outlaw
964 C2 1992mod
924 Carrera GTS Look(Project)
924Na stock 1982Mod
*911S Targa slantnose 1975mod
*924Na 1977Mod Carrera GT kit
*944NA Type 1 1984Mod
*924 Turbo Serie2 1980mod
*924 Turbo Serie2 1980Mod
*924NA 1982Mod

931 twinturbo · Joined: 20 Jun 2007 Posts: 122 Location: Norway

Or is it the waterpump infront of the cambelt???
_________________
911 Targa 1974 Turbolook/Outlaw
964 C2 1992mod
924 Carrera GTS Look(Project)
924Na stock 1982Mod
*911S Targa slantnose 1975mod
*924Na 1977Mod Carrera GT kit
*944NA Type 1 1984Mod
*924 Turbo Serie2 1980mod
*924 Turbo Serie2 1980Mod
*924NA 1982Mod

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

Only difference between mine and factory one is that lower end-tank is oriented to the other side (drivers side on LH drive cars). Otherwise it's the same.

Peter Utzon had few scans from GTR factory manual and there was a pic of the whole GTR engine together with IC. Not there anymore, just dead link.

The intercooler core on the Freisinger car is exactly the same as mine, even the stickers are the same. It's a Garrett AiResearch core.

_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

bass gt · Posted: Thu Feb 12, 2009 1:32 am Post subject:

Thats the water pump in front of the cam belt. Or rather an additional pump, as the GTR's were notorious for popping their head gasket any time the motor ran over 85degs.
However, when you look at the GTR engine in respect of the modern techniques, there are some pretty horrid things going on. For example, having the IC fed from the bottom is less than ideal due to the inherent heat soak. Heat rises, and unless the IC is kept cool, the overall efficiency decreases. Also note that the IC is hidden behind oil coolers ect, severely reducing it's efficiency. Also remember that the GTR ran a CR of about 6.7:1. That would be an awful motor to drive at anything less than flat out, but this was the only way to control pre ignition in those days. For example, i have pulled 420ish from my 8.5:1 motor and whilst the cam required to do this make it a nasty engine, the ECU allows such fine control of the fuel & air mix and ignition timing that such things are possible. As another example, Simsport released 25BHP+ from his supercharged motor just by swapping from Emerald engine management to Motec. You really do get what you pay for. So to build a "close " GTR motor seems a curious choice, when you can use stock parts and achieve the same, if not better results. As i said before, i suspect that when you start looking into the special parts required to create a GTR engine, or something close, the reality of 924 performance parts and their availability may just realign your hopes. Not saying it can't be done, but there are enough of us oldies here to know that whatever Porsche made for the 924 was done in tiny quantities, and are just not available any more. However, if you pockets are that deep, a good place to start might be Freisinger Motorsport themselves. As a reknowned specialist, they will probably have all the Porsche part numbers required. They might even be able to point you in the direction of suppliers ect.
Good Luck

Steve
_________________
Front Wheel Drive is the Devil's work.

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

Looking at that IC pic again it seems that Freisinger has put the IC core backwards when assembling the intercooler. There are arrows for boost and ambient airflow direction.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

bass gt · Posted: Thu Feb 12, 2009 1:41 am Post subject:

Raceboy,

Sorry, i was referring to the poition of the inlet pipe vs yours. The GTR turbo is on the LHS of the engine bay, whereas yours is in the stock 931 position i think.

Steve
_________________
Front Wheel Drive is the Devil's work.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

_________________
erstwhile owner of just about every 924 variant ever made