924Board.org

[931Owner]

Ok... it looks as if the S1 turbo is in better condition than the S2 turbo.

What issues might I come across if I decide to go with the higher compression S2 engine and the larger S1 turbo?
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1980 Turbo
-too many cars and too many motobikes

[ideola]

Boost will come on later, and due to the larger turbine should produce ~7.5PSI at full boost. With DITC, this should be of fairly minimal concern, but you would be well-advised to run the highest octane fuel you can purchase (if you're not already). The Euro cars ran ~10PSI, so you should be safe at 7.5PSI. But the car will probably feel a bit different as the boost will come on later and will probably feel even a bit more non-linear to you as compared to the S2. But you'll also (theoretically) have a bit more power on the top end.
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erstwhile owner of just about every 924 variant ever made

[gegge]

Cédric is running just that combination and he is VERY happy with it.

Just make sure that it is the larger K2664 and not the smaller K2470, and keep the smaller S2 turbinehousing.
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Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

[Cedric]

As gegge said i´m running the turbo that gegge writes about for the same reason as you. Nice uppgrade, it runs with a s1 spring, 0.7 bar. Boost comes on much later, couple of hundred rpms later, but the mid range/top end is much more punchier. Makes the s2 engine much more fun, swap it !

I run with vpower 99 okt for safety reasons but it runs as fine with 98 oct.

Swap it now, it will be a joy !
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1980 924 Turbo
www.instagram.com/garagecedric/

[931Owner]

Thanks guys! S1 turbo it is...
So are you running the S1 oval or the S2 circular intakes?
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1980 Turbo
-too many cars and too many motobikes

[ideola]

I have the S2 intake tract on mine.
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erstwhile owner of just about every 924 variant ever made

[Cedric]

[931Owner]

[ideola]

Use the S2 intake, by all means. The 941 is an S2 lump but with S1 turbo, CIS, and ignition.
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erstwhile owner of just about every 924 variant ever made

[Cedric]

[ideola]

If he retains the S1 ignition, the only wiring modification required that I can think of at the moment is at the TPS.
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erstwhile owner of just about every 924 variant ever made

[Cedric]

[Grenadiers]

' but maybe it works with low boost us spec'

Insulting.

Just kidding though~! I did the whole S1 intake drop to the S2 when I fitted the CGT TMIC jobby, a couple wires, and they match, and works great. I had to skip the SII throttle cam and reuse the SI version, for reasons I forgot, but it works too! Oh, I recall that the throttle cable length was wrong. Had to reuse the throttle cable 'stop' from the SI as well, I think. grrr, middle-age.
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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

[931Owner]

Ah... what is a TPS?
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1980 Turbo
-too many cars and too many motobikes

[ideola]

TPS = Throttle Position Switch. The S1 has dual microswitches, the S2 has a single multi-pin TPS.
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erstwhile owner of just about every 924 variant ever made