I have been looking at some of the ram air hoods that are available and I have also been looking at installing a pair of compound turbos. So my question is...what volume of intake air is required on a 5.9l? If you look at most class 8 trucks with approx. 15l displacement they do not have much larger intakes than the aftermarket units that we run on our trucks. Is there a formula to calculate the air required? Thank you, k.si.

 

a ram air hood will probably not give you any extra air at all. They are mostly just for decoration. I dont think that air intake is a problem, once you go to twins a good filter will be sufficient

 

You need to look at the specs or compressor map for the big turbo. Map's are usually in lbs/min. Multiply that by 15 and you will have the approx CFM that you need. Then you can figure out what filter is adequate.

 

Getting clean fresh air is always a good idea. I know my compound air filter gets black in hurry. Even if you can boost inlet pressure by a few inH2O (more density), you'll increase inlet volume of the compressor. Garrett/turbonetic's has some good information.
http://www.turbobygarrett.com/turbob...ch_center.html

http://www.turboneticsinc.com/content/compressor-maps

Pratio= (ambient pressure+boost(gauge pressure))/ambient pressure

 

Thank you for the information, I have a lot to learn about the dark art of turbo chargers. I have spent enough time on the computer researching the subject matter that my wife refers to it as "turbo ****".

 

As long as you look and not touch, you could have no issues with the wifey. As much math as you can do, it can only give you a rough idea of what you want. The best way is to try a bunch of different combos, there is nothing wrong with trying to find the perfect set-up for twins. Best place to start for a home build, is to use the stock top turbo and buy a decent primary either a K-31, S475, BTH-3B, GT4202 for the guys running under 700rwhp. Over that you might want something abit bigger. The primary turbine housing size makes a big different on how everything works. If your more inclined, throw in an external gate on the exhaust manifold, you'll probably gain 100-150 rwhp of room with the same set-up. You'll have fast spool-up and lots of top end.

 

- dont use paper style filters

-try to make sure the air going into your intake has not just passed through the rad or anything else that will have heated it up

- (psi of boost / 14.7) + 1 X CID X max rpm / 20,839 = square inches needed

this is from my turbo book good luck

 

Thank you for all of the information and a Merry Christmas to all.

 

I took out soft plugs in front of #1 and 6 cly,
made plugs 1 1/2" x 4" long to insert in there place.
Went to midas had 1 1/2" tubing bent on 45 and ends
flared for hose. welded short tubes in intake tube, connected
everything with hose and clamps. Have air across intake now.