How much heat wrap needed?
 

as above how much is needed on downpipe? Is there and better make or does it all do the same thing Thanks

I would be interested in the answer to this?

DEI is the best. As can be seen on demon Tweeks website, http://www.demon-tweeks.co.uk/perfor...g-protection-2.
If I remeber rightly DEI do a guide,
http://www.designengineering.com/nit...wrap_calc.html

Hope this helps.

Just be a little careful if you live in a rusty environment, I just had to replacement by down pipe as under the heat wrap was completely rotten!

Thanks il order some now is it worth getting Silcone coating?

To answer the question, as i have recently done mine, the 2 inch by 15 foot roll is enough to do a downpipe with some to spare