Several manufacturers of intercoolers provide a horsepower rating for the different products that they offer.
I was curious to know how these horsepower ratings were established. I’ve never come across an explanation for where the intercooler horsepower rating comes from, and it seems like it would be a hard number to determine.
I decided to contact a few manufacturers that assign horsepower ratings to their intercoolers to learn how they arrived at the numbers.
A couple of them responded.
You ask a good question. To be honest there isn’t an industry standard for this rating. This is just a rating we use based on the fin configuration of the core used in the complete assembly. Could you use a core that is rated at 400hp in a vehicle that is making more power? The short answer is yes BUT it wouldn’t be as efficient in cooling the charge air temperature.Turbonetics / Spearco
There is no magic HP number for intercooler. The intercooler function depends on the following:
1. How much air is flowing through the intercooler i.e. the air velocity through the intercooler core. This depends on where you mount it and how the air flows over it. Usually you are targeting 15 to 20mph of air through intercooler. Also, you are looking to slow down the air coming in thus increasing its pressure so it will goi through a thick (3.5″, in your case core).
2. Next you need to look at how much air will flow through the inside of the intercooler and what the temperature and pressure drop will be. There is usually a chart with this spec against external air flow and intercooler efficiency.
3. You want to stay at 70% intercooler efficiency at 15mph external air flow. This is determined by intercooler construction i.e. bar-and-plate or tube-and-fin and the overall intercooler size and core width.
4. #3 with #2 determines the ‘HP rating’. It is not a real or abolute rating. The same intercooler can support 1000HP or 100HP. At 100HP it will work much better (less air to cool) at 1000HP, it may not be so effective.
5. All of this is a compromise of size (since you need to mount it) and performance. Ideally, you would run a huuuge intercooler.Treadstone
Thank you for contacting Holley Performance. The power rating is designated by our engineers and their findings during testing. To my knowledge, there isn’t an industry standard for this testing.
If you have any other questions or concerns please feel free to let us know. We appreciate your businessHolley Performance / Frostbite
There is no standardized method for assigning a horsepower rating to an intercooler.
Absent a standardized method for determining the horsepower rating of an intercooler, making a comparison between different vendors’ products, based on HP rating, is pointless.
The rating is perhaps slightly useful for comparing products available from the same vendor. Though it is likely that the HP rating is going to track closely with the sizes of the vendor’s intercoolers.