Hi

Ive ordered 50mm itb's for my NA 13b turbo 2 4 port engine (engine is converted to NA) and the ida intake manifold from tweakit, but now after a bit more searching it seems it might be better to go for the 55mm itb's for the bridgeport (engine is currently at builder and will be bridgeported and rebuilt) the order is still processing and i am in the middle of confirming that I want the alloy fuel rails as the stainless ones arent in stock so it is still possible for me to change my order, i dont want to go too big or too small and want to get this right as it is obviously alot of money, i saw on site that 55mm is recommended for bp, what do you guys think? ive tried searching but throttle bodies are rarely used and difficult to find info on.

Thanks in advance

 

50mm's will be fine. I run the 50mm's on my PP's and have no problems. The 55's will be less responsive also