Bonnet raisers

[shentyt]

Has anyone ever used or fitted bonnet raisers and do they make much difference to engine heat or is it more of a cosmetic mod really??
I'm buying some regardless just wanted to hear what other people's thoughts are

 

[pollyp]

I lifted my bonnet with some central heating copper pipe and longer bolts.

on my turbo it allows the heat to escape out the bay, especially during traffic, and in theory lowers engine bay pressure for the radiator to work.

tested the airflow here
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-108#post-683082

 

[shentyt]

Well mine is only a 1.0 litre so is more cosmetic then I guess but will be a good idea for the sr20 turbo conversion