What are manifold insulators? What do they do? How do they work?

[Commowar]

Wish I'd looked into this first. The install picture probably doesn't give a clear enough indication. May be worth noting that little detail. Thankfully it's o2 and cat safe anyway.

 

[Commowar]

Took it for the first test drive today. Must say I'm very happy with it. Noticabley more low down torque. Thought I'd see how quick it was off the line, put the foot down and the wheels started spinning. I wasn't expecting that took me by surprise. Nice work mace.