So I bought 1 1/4" piping for my twin scroll manifold and I also bought a 1 1/2" pre fabbed collector. Now I was told by a member on here that he suggested 1 1/4" piping for the runners but they look a little small. Im just worried it wont flow enough?
The turbo im running is an HX40/HX35.

If they are to small ill just buy 1 1/2" but I wouldnt like to waste all the pipes I just bought.

Thoughts?

1 1/4" will be good for that. You won't be moving enough air through it to need 1 1/2" runners. 1 1/4" will give you a quicker spool anyway because the air will be moving at a higher velocity.

Ah ok that makes sense. I dont feel so bad now haha

1 1/4 into a 1 1/2 collector is going to be a little weird...

That part might be a little funky. Might want to do a 1 1/4" collector.

The longer the runners and larger diameter is better for top end.

The shorter the runners and smaller diameter better for bottom end.

Well I couldnt find a 1 1/4 collector unfortunately and I really didnt want to make one so I might just make it work. I know its gonna look a little weird with a 1 1/2 collector but it wont affect spool in a bad way right?