When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
A Dawes device is a good way to either blow your engine up or to gain a rediculous amount of power safely for a lowly price of 50 quid. Its cheap and simple to use. Unfortunately abusing it (i.e. trying to get 40 psi) would be a one way ticket to the breakers.