Has anyone completed a test to compare a screen vs an air filter on the dyno or track?

I am not sure if my filters are large enough or clean enough to provide enough air for my combo and I am considering adding screens for a dyno pull to find out if my filters are a restriction...

I was just curious if anyone has done this?

Maybe I should just do a pull with the filters off?

 

I did, several times. I was convinced my 5" K&N filter was holding me back. I made back to back passes on the same day with and without.........to my surprise....no difference.

 

Cool thanks!

 

I put a single metal screen from screen door matterial on mine, and went for a drive without the splash shield in the wheelwell. To my surprise I looked at it the next day and there was a nickel sized hole in the screen. Whatever got sucked in the turbo got ground up and went through the motor. there was no trace of anything, so Im hoping it was a big bee or something, but if you end up using screen, use more than one layer for sure. I put my stubby 5" k&n back on it to be safe.

Mike

 

Thanks

 

The only way to tell the difference is by logging back pressure and iat's. I don't use a filter or screen currently but not any chance of stuff flying into the compressor (I keep my engine bay kind of clean).

 

Screens usually restrict flow more than a filter its about surface area. Screen right on the cover gives you a smaller area of flow since the metal mesh diverts it , where an air filter doesn't actually restrict the volute inlet itself and is usually designed to flow depending on the type of filter. Your boost level is set by the gate either way so the turbo will just work harder to overcome any restriction in flow to get to that desired boost level, unless your already taxing the turbo on your setup you will never really see a difference in boost or power per say. Like mentioned you may be able to measure a difference in iat's and back pressure. That being said, at a track rental had buddy running consistent 10.0XX's and he was wanting to get into 9's that day, we took off the turbo inlet tube and filter and next run he had a 9.9XX. Likely due to the above mentioned reasons, it all depends on how hard the turbo is working on your setup at your power level.

Run whichever makes you feel comfortable, I run a standard air filter on the street, if I was going for max all out et at the track I would remove it for the run etc. Every setup will be different on how or if it responds.

I wouldn't try to boot leg a screen out any old flexible material from a hardware store as it wont be strong enough and is an accident waiting to happen, if you do choose a screen get a legit one that is rigid enough to hold up to that use.

 

Thanks guys

 

I ran screens on my Twin Turbo SBC and after a few runs I noticed that my screens were caving in towards the inlet of the turbo's. This led me to believe that they were causing a bit of restriction plus I would think that it disrupts the airflow a bit. So I took them off and the car did go a bit faster.

To be fair about it though I was having traction issues and still tuning the car at the time so I cannot confirm that taking the screens of the turbos gave me any real gains. FWIW

I would say take them off at the track and the dyno and put them on when you are street driving.

 

https://www.google.com/search?rlz=1...17.0....0...1c.1.64.hp..1.16.1974.Vj8vapRK6rQ

id look into something like the above link and make it cone shaped or tube shaped to increase surface area

maybe block the end so air would come in from the sides and bugs would hit the end ????

kinda like a screen on a trash pump pick up

 

A friend of mine with a turbo car was running a very small spectre filter...the real short like 2" tall jobs. I swore to him at his power level (mid 300s with at the time a 1.3L) that he needs to run a full size cone. Well they dyno'd it. Actually loss a few whp with a much larger K&N. However they also tried open pipe and it lost a few more. Somehow the stubby Spectre filter just happen to work right in his particular situation.

The point of my story is to just test it out. And street cars really should run a filter at all times...why wear out the turbo and motor sooner then later?

 

Yes i will run a filter on the street for sure and i will do a dyno test with them off just to see if they are hurting it or not...

 

Be sure nothing can move within touching distance of the impeller..

One thing to be very aware of is FOD foreign object damage is a bitch. I had very thin aluminum leading to my filter. On a 90 + degree day after a long drive I hammer it. the aluminum sheetmetal sucked in slightly deforming. I was on my way to the dyno and once they I pulled my filter and tubing off. Long story short without anything protecting the impeller the dyno tech placed the mag pickup on #1 spark wire behind the blower - just saying that at 6000rpm a magnetic pickup will shredded by the impeller, shot through the carb with parts exiting the exhaust pipe and imbedding in the wall of a shop

Be sure nothing can move within touching distance of the impeller..