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Elektrobank · Posted: Tue Feb 03, 2009 8:06 am Post subject: Intake manifold, upgrading to S2

Hi All!

i'm sourcing parts around for my engine rebuild...

since i decided that a 944 intercooler will be fitted to my 1980 931
i done a research around the forum and about the intake manifold, my 1980 931 has the standard double batterfly manifod and i'd like to fit the S2 with single butterfly but i don't find pictures or something usefoul...

so now i'm asking to you guys...
what parts are needed to do a conversion?
any benefit in an upgrade like this?
what kind of mods are needed?

i'd like to plan everything before this rebuild...
many many thanks
Gianluca
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924T Dta inj + sequential LPG
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MotoMorini 501
Moto Morini 350 K2
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ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Take a look at the engine bay pix for my 941, which was converted from a SI to SII intake setup.

At minimum you'll need the intake manifold itself, the throttle body, the TB gasket that goes between the TB and the mani, the two gaskets that go between the upper charge tube and the TB (a smaller red donut that is hidden inside the charge tube, and a larger black donut that is visible externally), the upper charge tube, and probably the throttle cable linkage brackets.

The SII intake mani will have an Intake Air Temp (IAT) sensor, which can stay in its home, but won't have anywhere to plug into, no big deal, just make sure it comes with the mani, or you'll need to otherwise plug that hole. You'll also have a vac line on the TB that will need to be blocked off, which is plumbed into the DITC box for manifold pressure. Again, no biggie. Pix of my engine bay reveal most of these details. I can't think of anything else at the moment.
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erstwhile owner of just about every 924 variant ever made

Elektrobank · Posted: Tue Feb 03, 2009 10:15 pm Post subject:

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

I don't even think you need to change the cable, just the bracket arrangement that positions it for the throttle cam. You might need to swap the throttle cam from your SI throttle to the SII throttle, as I believe the ends are different.
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erstwhile owner of just about every 924 variant ever made