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931 Rally Monte Carlo Historique TLC+
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 1364
Location: Somerset, UK

PostPosted: Wed May 03, 2017 7:26 pm    Post subject: Reply with quote

Back in '79/'80/'81 the Porsche entered 924 turbo ran several iterations of the turbo including a crude top mounted IC for the Monte Carlo rallies. They also ran the CGT spec motor/chassis in a 924 turbo body. The CGT and GTS upgrades are all listed in the homologation papers which can be found online. I can't find a link right now. Some of those upgrades should be allowable in group 4.

There is a casting number on the hotside of the turbo which is hard to see when fitted to the motor which would tell you if you have a #4 or #6 hotside. Knowing which compressor is fitted is harder unless pulled apart. I wouldn't worry too much now.

Mittelmotor are running a CGT with all GTS upgrades in FIA Historique racing. Whilst this is track and not rally, there will be upgrades that can be allowed depending on aiming for group 3 or 4 spec. They run higher boost and a 123ignition based programmable distributor to get their car close to 400bhp! This is with additional GTS spec fueling and IC. The turbo, CGT and GTS spec cars did rally with Jurgen Barth at the wheel.

My car is running their dizzy, a 944 front mounted IC and manual boost controller with many other upgrades pushing power over CGT bhp. But as mentioned, an AFR, boost and potentially a knock sensor would be advisable if the car is going to be worked hard

So, I think consensus is to get the car running well first whilst learning and doing some homework on allowable/desirable upgrades. Some may be scrutineered harder than others. Some may be easy to apply and not found. Some may be outside the 'spirit of competition'.

I wish this was my car. I have a rally car itch that needs scratching!!
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1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 1364
Location: Somerset, UK

PostPosted: Wed May 03, 2017 7:36 pm    Post subject: Reply with quote

Link to 924 turbo and Carrera GT/GTS homologation papers http://www.porformance.nl/categorie.php?cat=56
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1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
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Harm  



Joined: 02 Apr 2009
Posts: 1278
Location: Holland

PostPosted: Thu May 04, 2017 4:53 am    Post subject: Re: 931 Rally Monte Carlo Historique TLC+ Reply with quote

Carrera RSR wrote:
Back in '79/'80/'81 the Porsche entered 924 turbo ran several iterations of the turbo including a crude top mounted IC for the Monte Carlo rallies.

The Porsche 924 that entered the Monte Carlo Rally in 1979 had no Turbo thanks to the homologation rules.
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Porsche 924 NA 1982 LY7A/A3A3 _ Greater driving pleasure never harmed anyone.
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kghaas  



Joined: 01 May 2017
Posts: 6
Location: Oslo, Norway

PostPosted: Thu May 04, 2017 5:02 am    Post subject: Reply with quote

Again: many thanks for useful comments and tips.
As for Homologation, it is probably not that big a deal. These cars don't get scrutinised that often, but I would like to keep it close to the specs. Realy interesting about the GTS homologation info.

I have ordered some service parts and pulled the brakes. Will hone the calipers and install fresh rubber as soon as it arrives.


OT:
While waiting for Porsche parts I have started to put together my other racer. An MG Midget which I have raced in historic Racing (track). I have had the car for 20+ years but have now done some major TLC including machine turning the door sides with a hand drill!

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Knut
931 RMCH
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 1364
Location: Somerset, UK

PostPosted: Thu May 04, 2017 5:31 am    Post subject: Re: 931 Rally Monte Carlo Historique TLC+ Reply with quote

Harm wrote:
Carrera RSR wrote:
Back in '79/'80/'81 the Porsche entered 924 turbo ran several iterations of the turbo including a crude top mounted IC for the Monte Carlo rallies.

The Porsche 924 that entered the Monte Carlo Rally in 1979 had no Turbo thanks to the homologation rules.


Aware of that

Production line issues meant they didn't build enough engines/cars in time. Is it the rules fault?
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1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
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kghaas  



Joined: 01 May 2017
Posts: 6
Location: Oslo, Norway

PostPosted: Mon May 08, 2017 4:37 am    Post subject: Reply with quote

Front calipers are now honed and with fresh rubber.
New tiiming belt and roller
New oil an oil filter
Degreased the engine and front crossmember for 20 years of gunk.
cleaned the sparkplugs (too nice to discard)
Running currently without airfilter, since I havent sourced this part yet. Will get a K&N or Pipercross one.

So: Car starts realy easy, and ideling is smooth and steady. But as soon as I try to rev it it feels like 3 cylinders.
Something might be off on the timing. Will check that later.
If anyone has any suggestions, they are more than welcome

https://www.youtube.com/watch?v=0-j-EezBY7c
[Youtube]https://www.youtube.com/watch?v=0-j-EezBY7c[/Youtube]
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Knut
931 RMCH
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