924Board.org

[emlynbeagler]

The turbocharger on my 1984 931 (Italian market model) has a rattling pop-off valve, is in the way of fixing an oil leak and needs to come off. I have a NOS S1 turbocharger (2664 G4.10 /5326 970 6407). From reading older posts, this appears to be a 1981-83 US market model. Some questions:

1) Is this a straight swap (I assume the answer is yes)?
2) What effect will this have on performance? (Assume a bit more top end, slower spool up and less low-down power)?
3) Is there anything that could be improved by hybridising the existing turbo and the NOS one? The existing turbo was rebuilt in 2007 and apart from the rattle is working well.

Is putting on the S1 turbo a good idea? Your thoughts, please.
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1984 924 Turbo
2017 Alfa Romeo Giulia Quadrifoglio
2017 Isuzu D-Max
1974 Moto Guzzi 850T

[Grenadiers]

S1 turbos where available only in 1980 for US models. Check the recycling valve in your current turbo for the rattling first. Remove both covers and see if the rubber gasket is missing. It's obviously spring loaded, and getting the bolts out on the frame side is a pain. 93011014900 is the PET number and Pelican has them for about 4 bucks a piece. If the gaskets are missing this can cause a vacuum leak.
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'83 944 Track car.
'88 924S Track car.
'89 944 Turbo
2004 Winnebago Vectra monster RV
2012 Jeep Wrangler
2014 Kia Soul
2001 Ford F350 powerstroke

[Cedric]

Hi !

I changed my s2 turbo to the 2664 G4.10. It will have some effects. You will loose bottom end boost, but it will pull much better at high revs. Especially when you push it for a long time on track the heat was very noticable on the stock charger. A little less practical but much more fun to summarize it. highway fuel economy was a tad worse as well, but it doesnt matter for me.

Here is a dyno sheet, 168 HP at the hubs, though with S1 waste gate.


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1980 924 Turbo
www.instagram.com/garagecedric/

[Fasteddie313]

I made those round washer like BOV gaskets out of an old leather boot, cut out the rings then soaked them in oil. The gaskets that came out looked crystallized almost..

I think that clattering could be caused/exaggerated by a vacuum leak in the BOV vacuum reference line, the rubber elbow coming off the housing, to a steel pipe, then another hose from that pipe connecting under the manifold.

That turbo being a 6407 should have the latest revision for the aluminum ring between the turbine housing and the exhaust manifold, worst comes to worst you would have to swap the turbine housings but I think thats unlikely..

If your going to try to replace those gaskets without removing the turbo I think I heard someone reference the FSM saying something about removing the water pump to gain better access.
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80 Turbo - Slightly Modified

[Cedric]

I bought a new replacement gasket for the bov from porsche. It was a completely different material to the destroyed original gasket. The original one was all smeared out and made the bov stick open.
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1980 924 Turbo
www.instagram.com/garagecedric/