Newbie with questions

[S18rra]

Hi all I'm very new to the supercharge world and also to water/meth injection.
I have a tiger avon kit car with a 2ltr blacktop zetec engine and eaton m45 supercharger.
The charger is bolted directly to the bottom of a custom plenum so has no cooling, tb is before the charger and really struggle with space so hence this setup.
I recently went on the rollers and was disappointed with the results at 163bhp and apparently it was mainly due to the high temp. Inlet temps got up to 80'c for a few seconds when on wot.
Because of the lack of space I'm considering fitting a water/meth injection kit, question is where would be best to place the jets? Into charger, plenum?
Here are a few pictures of the setup



You can just see the charger under the plenum.