Tillotson hw 27 a carburator manifold

Hi i have my app that has an option to choose what carburator i have so i get exact settings. I run x30 junior with the new exhaust. What does flex mean and 1 piece exhaust. And explain what manifold is please

This explains the flex part: X30 Exhaust Notes — Fox + Son Karting

“Changes to the exhaust length are made by using different sizes of flexible steel pipe (referred to as “flex”) between the header and the actual pipe. A longer exhaust length gives you better bottom end power and a shorter length gives you more top end. Changing your exhaust length is akin to changing your gearing.”

Exhaust manifold:

What an exhaust manifold does:
https://www.brodiestireandautomotive.com/Auto-Repair/Automotive-Q-A/mode/detail/KnowledgeItemId/2669

One piece vs 2 piece exhaust thread:

Depends where you are. Here it’s one piece, you’re not allowed to compete with a flex exhaust, won’t pass scrutineering.

The X30 originally had what’s called a “flex pipe”, which was an adjustable length piece of pipe that went between the exhaust and the exhaust header. You could use this to adjust the powerband of the engine. Recently they switched to a single piece exhaust that no longer has that adjustable pipe in the middle before connecting to the engine. It’s one piece of tube from the back of the engine to the exit of the exhaust.

I have 1 piece but what are the mm for in the app (manifold)

There is an adapter for the one piece that can be used to tune the exhaust with. Not sure anyone is using it though.

I have always used that adaptor … But recently my mechanic told me not to, because without, would give me a little more torque in the middle band… I have not tried yet …