View Full Version : 30v throttle body on a 1.8

08-05-2013, 06:44 AM
So I have a new custom intake manifold for my car. It was made to use a 30v 70mm throttle body.

Now my question is, is the throttle body a direct bolt on for a DBW car, or will I need to get the scaling altered in my tune? I know 034 makes a kit to bolt a 70mm throttle body up to a stock intake manifold, but it doesn't seem like a common mod. Just wondering if it was because of a tuning issue? I tried searching, but didn't really come up with much.

08-05-2013, 07:30 AM
What custom IM did you get? If your custom IM is for a 70mm tb, it should bolt right up and the connection should be the same. You will need to modify your tune. I'm not an expert, but I have an S4 tb and a RS4 tb and they look the same, just the size is different. Here's a pretty good thread about tb.


08-05-2013, 12:03 PM
You can copy the normalized airflow over throttle plate map and its inverse from the software the TB came from, or multiply the map by the NEW AREA/OLD AREA. That will get you close.

Without doing that, the ECU will open the throttle body too far for a given torque request, and the idle won't be too happy either.

08-05-2013, 03:57 PM
Not going to gain anything by running a 70mm throttle body with a 2871r.