Thought I'd share how we've done it on several EFI 911 Turbos getting a Carrera manifold. This works very well, is reliable & serviceable:
* Do not cut & rotate throttle body -- re-making that throttle linkage to get the same progressive pedal ratio as stock is no fun. You don't want a twitchy throttle in a street car, something difficult to control smoothly at low speeds.
* Make a 3" tube from the IC to the T-body. Use as little silicone hose as possible as it doesn't like oil + heat (and all turbochargers bypass some oil into the charge pipes -- makes the silicone swell out) . We make & sell a bolt-down flange that seals to the T-body with an o-ring, receives a 3" OD aluminum tube. Simple.
* Join the tube to the IC as close to the IC as possible so it is easy to access -- no reaching behind the intercooler, burning your arms or grating your knuckles. Using one of Hargett's QDCs are a clean solution, and sometimes easier than the Wiggins clamps.
* Locate all your "intercooler" fittings in this T-body pipe: idle motor, air temp, diverter valve and/or port, boost source fitting... whatever.
Why?
If you have to remove the intercooler to access the rest of the engine, you're not unhooking a lot of little connections that are easily forgotten (rather dramatic when you forget to re-connect the wastegate's boost source and it overboosts). All that stuff stays connected, you just undo the inlet & outlet and whatever mounts you have.
Simple, serviceable. And tidy.
And not expensive.
A few pictures:
3.2L Carrera on 3.6L 930 (550rwhp on 91-octane pump)
A 1992 3.8L 964 converted to a simple single turbo (450rwhp on 91-octane, 522rwhp on 100-oct)
1995 993 converted to turbo (shipper system).
The connection is right on the back of the intercooler, easy to reach standing at the right rear corner of the car. A little spray lube, slide the silicone connector into place, clamp it down. Or use a QDC.
Re-fabricate a c-f of a setup on a 964 3.8L twin turbo...
Here, the connection is set far back in the engine compartment and the intercooler close to the top edge of the engine compartment / upper drip rail. No fun getting your arm back there to slide the connector from one piece of tubing over the other, you had to reach under the IC. This car ate skin off the back of your knuckles. Wouldn't be a picnic with a QDC, either.
Regards,