Mike you have the cowl like vents on each side where windshield ends correct. And then a single side vent on each side. Any way possible to get any other slim billet ones across the rear at same height as side ones or otherwise a little lower if need be. CP has a number of shapes and sizes as I'm sure you know.

Along with that is it possible to enlarge the forward cowl type ones even if you need to fabricate some custom vents. If I recall you don't have an over abundance of area there to enlarge but even a little could go a long way. I honestly believe your taking in no where near enough air and also not getting rid of what's coming in while obviously building lots of unwanted heat making tuning a nightmare as well.

Next time out pull all of your vents/cowls right out altogether. Ck out defender.com just to get an idea of some possibilities or ideas.

http://www.defender.com/category.jsp...139&id=2290141


Not sure if you'd have any use for any of these however gives you some ideas. Get some dryer vent hose and duck tape also. Lol. All chit aside you need to get more air in and out of there.

Really ??? anyway to move air thru the engine room and remove heat is a plus...

I just bought 4 nice 2" x 7" stainless vents that are used in the Donzi ZR boats. I think I'm going to evenly space them across the back of the boat. I can't really mount them on the sides without making the boat look cobbled up. When I come up next weekend, I'm going to pull the cowl vents and see how many holes are in the box's that the air initially goes into. I may be able to add an additional hole there.

Here are the pictures of the vents I bought and I'm going to build these over the winter for the hatch. I think the rear vents will help both the heat escape and allow more air in.

EZSTRIPER - Those fans exhaust the engine compartment they don't suck air in except by causing a negative pressure inside the engine compartment. Even if you installed them to pull air into the engine compartment all they would do is restrict the flow because the engines draw a LOT more air than what those fans will pull in. The open hole with the fan removed would allow more air flow. What they need is more or bigger holes to let air in.
You may not realize that I am an air flow specialist.

I guarantee you that at WFO even IF they had the fans on blowing out air would be going in instead. I tried everything on the SCARAB.

Steve-
What do you think about what I am considering to increase the flow of air. I'm not sure if the 4 vents in the back will do a lot, but I think the large cowl vent on the hatch will work well, plus the sun pad will still be usable.

I don't remember what's behind your rear seat bottom and side but like other post mentioned that may be a possibility also. Take a look and see unless you already know however that's an area you could use something similar to link. Anything to get more air in there. I like your idea mentioned above and can only help. Might have to put a 12" sub grill in the middle of your back seat. Lol. Will be interesting to see what possibilities you may have along the sides of rear seat as well as enlarging the opening behind cowls.

I was thinking exact same. Open speaker holes with grilles.

Area of a 12" hole = 113.09734
Area of 2 x 6" holes = 56.54

^^^He does know what he is talking about^^^

Most 3" bilge blowers are 'rated' at 140cfm. Most 4" are rated at 240 cfm.

Each of your motors are demanding around 900cfm at WFO and top rpm. This is a very close accurate guess from many dyno's sheets measuring airflow on comparable motors. Therefore, your engines combined require 1800cfm ! That is a ton of air !

BTW: This subject is great and extremely impressed the OP tested this and reported it. Imagine how many people are running around with a performance boat and losing performance just like the OP ! And some, will perform more engine mods, drive mods, and etc, and still be choked down.

Many years ago, boat manufacturers started to become more aware of NVH (noise, vibration, harsheness) and started instituting methods to reduce thismore and more as time went on to make the boating experience even better. What's the easiest way ? Not just sounds insulation materials, but reducing the # and size of engine compartment openings. Ooops !

Remember, there is a reason the big old Apaches had big raised decks with holes or screens all over the place. Air !

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http://www.rrbaonline.com/wp-content...acker_idle.jpg

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