My car came from Japan with the notorious HKS Mushroom filter. Although it supposedly flows air without much restriction, it also flows engine-damaging debris without much restriction! It might keep out pebbles and small birds, but it allows everything else to pass right through. Here is the offending piece:
You can see in this article just how badly that thing “filters”. My temporary solution to this poor filtration was to wrap that mushroom in a shop vac filter, while I waited for my K&N filter to arrive:
Speaking of K&N filters, they have a handy tool on their website to pick out a universal filter based on your own criteria such as length, diameter, etc. It’s best to choose as big a filter as you can fit, and so I did. There really weren’t all that may options for the flange diameter I was working with, so what I ended up with was a K&N RC-1637, a filter that fit the dimensions pretty closely.
The first thing to do was to pull out the HKS filter and the plastic MAF sensor holder from the intake.
The metal section bolted to the plastic is actually part of the HKS filter assembly, so it gets unbolted and removed. Next, the plastic flange that the metal flange bolted to would have to be removed. My Dremel worked nicely for that.
The cut edges were cleaned up, including a generous chamfer on the inner diameter of the plastic to keep turbulent airflow to a minimum. MAF sensors are sensitive to turbulent airflow, so the smoother the flow into the plastic section the better.
The new K&N filter slides onto the plastic MAF holder for a tight fit. See it compared to the HKS:
…and back into the car. The RC1637 filter happens to have an offset flange which was only coincidental to the filter having the right dimensions, but the offset helps to position the filter in the engine bay when you can twist it around to change the way it sits.
Still to come is a home-made heat shield to help keep the turbo heat away from the intake air.
Cost breakdown:
$35 - K&N RC-1637
You can see in this article just how badly that thing “filters”. My temporary solution to this poor filtration was to wrap that mushroom in a shop vac filter, while I waited for my K&N filter to arrive:
Speaking of K&N filters, they have a handy tool on their website to pick out a universal filter based on your own criteria such as length, diameter, etc. It’s best to choose as big a filter as you can fit, and so I did. There really weren’t all that may options for the flange diameter I was working with, so what I ended up with was a K&N RC-1637, a filter that fit the dimensions pretty closely.
The first thing to do was to pull out the HKS filter and the plastic MAF sensor holder from the intake.
The metal section bolted to the plastic is actually part of the HKS filter assembly, so it gets unbolted and removed. Next, the plastic flange that the metal flange bolted to would have to be removed. My Dremel worked nicely for that.
The cut edges were cleaned up, including a generous chamfer on the inner diameter of the plastic to keep turbulent airflow to a minimum. MAF sensors are sensitive to turbulent airflow, so the smoother the flow into the plastic section the better.
The new K&N filter slides onto the plastic MAF holder for a tight fit. See it compared to the HKS:
…and back into the car. The RC1637 filter happens to have an offset flange which was only coincidental to the filter having the right dimensions, but the offset helps to position the filter in the engine bay when you can twist it around to change the way it sits.
Still to come is a home-made heat shield to help keep the turbo heat away from the intake air.
Cost breakdown:
$35 - K&N RC-1637
No comments:
Post a Comment