Hi,

Im in the middle of modifying my induction kit for my 94 wrx, Does anyone know how to calculate the min volume required for a DIY sealed cold air box for an induction kit.

Cheers

 

Wouldn't matter too much, it is more dependant on the feed of air to the box

 

As already stated all that is required is that the filter can breath freely. One air "box" I built was a plastic pipe with the largest diameter being that of the cone it fitted over. It was then budded up to the inner wing and breathed through an enlarged original snorkle hole.

 

Thanks Harvey,

yeah I remember you showed me that setup, You have seen what I had the other day when I came round to see your gauges.

What I have done now is scraped that and started again with a new sealed box made from aluminum and then insulated it further with ribbed cardboard and duct tape on the outside. It was completely sealed with a lid and the only access to air was through the original hole. It felt a bit restricted so I removed the lid. Thought It might need to be bigger. What I am thinking now is to feed a larger diameter air pipe straight from the front bumper.

I also went out to halfords and got one of those temp gauges you mentioned, good little piece of kit for the price. gives me a good indication of the temp within my air box.

Im also thinking of making a DIY air pressure gauge to test for restriction in the system.

have you done this yourself.

 

Make sure the box can get enough air.
I have not done any vacum measurements yet but it is in my mind to do so on the inlet tract and also some exhaust back pressure measurements would be interesting.

 

Im going to fabricate a large feed pipe once I have done my tests with some prototypes to get the best size and shape possible.

Probably do some vaccume tests either side of my air filter and test the restrictiveness against a cone filter I have.

What do you know about turbulance, and is there a way to test air filters, Im guessing that MY HKS would give less turbulance as apposed to the cheap cone filter I have. I bought the cone filter thinking It might give more air flow as it is substantially bigger than my HKS.