I currently have a small K&N filter on my T70 turbo. I've been doing some research lately regarding filter sizing and feel my filter is to small potentially hurting performance. The problem is I don't have much room. I could run a larger filter straight off the turbo, say 8" in length. But it would be close to the radiator. Or I could run an even larger filter if I routed some piping with a couple of 90* turns away from the radiator. But I've also heard adding Bends could hurt more. I could 90 down off of the turbo and 90 to the left with a filter (picture with red line). Or use a short radious 90 off of the turbo pointed away from the radiator. What do you guys suggest?

 

i suggest no filter. maybe a coarse wire mesh screen to keep out birds, bolts and belts

 

I would but it's street driven not a track only truck.

 

It takes some searching, but K & N has a section where it shows all the diff style air filters, and the dims.
I used a K&N RU-5109 on a BW S475 with a 5" opening with a short 45 deg bend.

 

I recall they also have a section suggesting surface area needed on the air filter to supply a specific amount of volume of air to the engine.

For example if you compare the surface area of the stock ls1 air filter to your current filter there is more surface area and it's for a stock engine.

Bob a Brute Speed pretty much confirmed the significant change in boost gained by changing to a bigger filter with a D1. Take a look on his site how large the filter needs to be even for the D1. Can't image that you would not get the same result with turbo's.

IMO the tradeoff will be that you might reduce air flow with a longer pipe and some bends but will gain it back by being able to use a much larger air filter.

 

same. my experience is every time we put a filter on turbo set ups it chokes the **** out of them. even the big *** 10"x5 " black hex R2C filter i had choked it out. sold it the next day on craigslist.


if you MUST, live on a dirt road or something, get a dry filter. skip KN crap and spectre crap. 100% waste of money.

 

I put an afe dry filter on the car it's about 10/12" long, pretty sure it was the largest avalible, and was in the $90 range.

 

Run a filter, not to is retarded imo

It's not gonna take **** to round up a filter too keep depression in check with a baby 70

 

No room ? Looks like there's a shitload of room there ?

Just pick one that suits, even one angled away from the rad slightly

( UK site but I'm sure US lists them too )

https://www.knfilters.co.uk/search/univcone.aspx

 

I just run a turbo guard Maxx on mine, and I drive it on the street also.

 

I thinking going to try out the R2C hex black series filter. Anyone here ever use one?

 

It has a wheel well covering it now.

 

i had the R2C black hex. I didnt really have to measure pressure differential, it was plain obvious it was choking it, even at low boost

I might give one of those big *** AFEs a shot if I lived on a dirt farm or had a dune buggy or something.

 

R2C works great on mine

Running it this way was drawing hot air from behind the radiator and you could see it in the IAT.



Built this to channel cooler air from the grill

 

From what research I've done a filter is always a restriction so I bought a cheap AutoZone filter and remove it when racing since its semi easy to access.
I've got the shitty kind of luck where a rock would bounce around under hood until it found my turbo inlet lol.

 

There was a post on YB I think, were someone tested no filter, short pipe and various filters etc.

The short pipe and filter produced a fair bit more power than no filter at all.

I cant see any reason at all not to run a filter unless it is purely a race car and you can afford to replace the unit if it does eat something.

 

That does not compute. Theres been others who've dyno'd back to back and gained power by removing the filter, i.e. restriction.

 

Agree with Stevie - perhaps most of us have forgotten the amount of trash forced up into the underside of the stock air filter by the air dam under the bumper on F-bodies - sometime even small pebbles, sand and gravel.

And same issue on the bottom 4 or five inches on the ac condenser and radiator. Usually filled with sand and gravel.

So not sure I would run without a filter even on a track - especially if running at 120 -130 mph on the backside.

I think the consensus is that air in a column is more efficiently digested into an intake than no column (pipe) at all.

 

And exactly what intake path and filter were they using ?

And how does it not compute ?

No filter or anything on the turbo could be quite a turbulent area to draw air from. Running some pipe, or better still pipe to a bellmouth would be a smoother flow path and undoubtedly be better.

If the filter is of adequate size to not restrict...which shouldnt be too difficult then again...there should be no downside, and a filter again can help to smooth airflow.

It would take a pretty nasty filter or massively undersized to pose a big enough restriction to really affect power. And lets face it, many run a crude screen or mesh directly over the turbo, which is probably by far the worst of all options

 

The results will be different for everybody. If the same boost is measured in the manifold each time, the turbo is just operating at a higher pressure ratio with the added restriction. Depending on the set up, the higher pressure ratio could bump you into a more efficient area on the compressor map.