that is one of the itrems that need to be tested on a engine or chassis dyno on the same day under very control testing standards to find out if it is good, bad or indifferent. Do you have a air inlet temperature gauge? If so then you should be able to see it the inlet temps drop with it on versus with it off and do the dyno test to see if the cooler limits the total airflow into the motor enough to cause a loss of HP or not. Hard to tell from here how restrictive or non restritive it is I did some dyno testing at a dyno shop that did a A,B,A test on a super chiller brtand,if I remember correctly, and it ended up being a big blockage to airflow on a 355 C.I.SB Chevy using a 6:71 with two carbs on top, the pressure above the cooler went up and the pressures below stayed the same as before installing it Definent loss of HP on the dyno sheets, even with cooler inlet temps