I'd like to get a little discussion going on the importance of proper air filter sizing and force inducting a vehicle. As some of you may be aware I've toasted 3 brand new turbonetics turbos all within a week of installing them on my car. I've worked with the manager at turbonetics tryin to diagnose the problem but everything checks out ie, oil feel/drain etc etc.

One thing I came across is an engineer discussing the importance of NOT creating a vacuum on the compressor side of the turbocharger in the intake tract which can be done by not having a large enough air filter. Doing so apparently pulls oil past the seal as well as can INSTANTLY SHATTER A COMPRESSOR WHEEL (which i experienced one time and the other two time the bushing wore out so bad the wheel rubbed the housing). So i got to thinking, I beleive my air filter may be causing all my whoas. It's nothing special, just a 3" cheapy cone filter from Discount Auto.

Then I found this...this is one area I NEVER researched when i built my turbo system for my car...

So according to that I need approx 600 CFM ([146.5 cid x 7000 rpm x 2.02 bars according #4 plus 1.0] / 3456) to be passed through the filter at Full boost and redline conditions which happens to be about 200CFMs MORE than what i think Im running now supposing the cheapy filters flow AS GOOD AS a K&N with the same deminsions which i highly doubt they do.

What do you guys think? Could the $20 air filter have cause me to run through $2k worth of turbochargers?

EDIT: can someone verify my calculations on a 2.4 liter at 15psi?

 

i really dont see that being the issue considering people run bigger power than you do and are not having the same issues. and you see how stock turbo cars get treated, they rarely get their filters changed by every day jane and jons...how much vacuum do you suspect is there when that filter is clogged to kingdom come? probably much more than your's and they still last quite a long time.

i vaguely remember the problems you had, but have you had any of these turbo's checked for balancing issues? when things shatter and bushings/bearings wear out very quickly, that is the 1st thing that comes to my mind.

 

also as far as your calculations go...the K&N website seems like an estimation of what you need. their numbers are based off a motor with 100% efficiency. at 7000rpm i really really doubt you are close to that just given the idea of typical valve events...but to just go along with it for the sake of argument, your numbers are right. but you also have to think about it a little too. the more vacuum there is, the more air is going to come past the filter. that filter at one point may flow that 600cfm you are lookin for, and you also need to take into account your PCV system if you are still running that into the intake piping because that would be another source of airflow. you have to also take into account the only way there will be no vacuum is having a huge filter and huge piping or running the turbo freely.