Runn

I installed my BBK TB and now the car has a loud whistle noise? Anyone else who has had this problem?

Thanks

Black Z/28

Yes, I had the hissing sound. But I was able to fix it. In my case, the problem was the gasket between the throttle body and the adapter. It protruded into the neck of the throttle body. It was seemingly minimal but it was enough to create a sharp edge for the air to tumble over. I sanded down the gasket to create a smooth transition from the throttle body to the gasket to the adapter. I have little or no hissing sound now- and mine was pretty loud initially.

Runn

I tried without the adapter and it sounds much better...

I think the problem is the sharp edge on the adapter there the air that passes the IAC meets the adapter?

Runn

What about running without the adapter plate...
Do i really need it?

Black Z/28

You're going to lose the smooth transition from the 80mm TB to your 75mm intake manifold.

Black Z/28

Or is the intake opening 78mm?... I forget.

Runn

I tested without the adapter and the hissing was lower... But i have located the problem it is the hole for the IAC. What should i do?
I´m thinking about drilling a hole in the throttle blade in the same size as the one in the stock throttlebody blade. Why isn´t it a hole in the BBK?

Runn

Ttt....