Throttle body options

[sc2_ct]

I am having idle problems (surging) with my 91 Talon TSI with an upgraded turbo. I checked the resistance of the 1+2 terminals to the ISC motor and it read 0 ohms, so I figure that after upgrading the turbo they didn't reset the BISS, causing the motor to burn out from being off-center and trying to move past it's limit.

Anyway, before I do anything, I wanted to know if there were any upgrades to the 91 TB? As I was looking at the throttle body elbow, the inlet looks pretty restrictive before it widens out just before the throttle plate. Is there an un-tapered adapter that I can use to connect the uic tubing? The bore of the TB at the throttle plate looks appreciably larger than the inlet bore diameter, which would seem at first glance to be illogical (lowering intake charge velocity before the throttle plate, as well as having the turbulance from a nearly 90-degree bend so close to the intake plenum wouldn't be my idea of performance-oriented. A straight-bore the diameter of the throttle plate would be much more practical from what I can see.

 

[Stanford]

The 95-99 throttle body elbow is larger that the 90-94 and this may be what you are looking for. When you buy upgraded IC pipes most companies replace the Elbow so if you are thinking of upgrading the IC piping don't bother with the 2nd gen elbow. As far as the TB goes, don't worry about it. You are thinking like you still have an N/A car, get that out of your system. It may look restrictive to you but it is the least of your worries. To answer your question though, there are upgrades for the TB but with a 300hp goal there is no reason to upgrade it. The upgrade I am talking about requires lots of custom work and a new intake manifold as well which does not come cheap.