Airflow problems, need opinions...

[Panelfantastic]

Most of you know about my bus with the Ecotec. I'm having problems moving enough air at speed to keep it cooled down. At idle it does fine, will cool right down, but cruising, it heats up. My bus is a panel with the divider right behind the seats that seperates the cargo area from the front, if I take the divider down and run with the safaris up/open, it runs cool as can be... but I don't want to run that way all the time. The cargo area is too noisy and sometimes the safaris are too much (interstate driving) so I need a new plan.

How I bring in air is from single NACAs on each side... I even added small "eyebrows" to them to try and help...


I'm thinking of going to double sized NACAs and a more extreme hood...




How do I know if I'm making a tall enough scoop?

I even tried a small roof scoop which did absolutely nothing !! It would have to be 2-3 times taller to get in the airflow... Why in the hell didn't one of you stop me from doing that???



Ideas? thoughts? comments?

[yetibone]

How 'bout pulling air in from underneath the Bus. Along with the enlarged NACA ducts, you could use a large scoop and duct from the floor up to the radiator.

Or, with more dificulty, 2 remote radiators placed in areas that see more airflow. Somewhere up front, ahead of the axle if there's room.

[jhelgesen]

I think the roof scoop would have to be much further forward on the cab to work. Does your bus have the fresh air vent over the windshield? Could pipe that through the cab if you had it.

I like the idea of the scoops under the bus. Don't want them too low though, would scoop up a lot of trash. Have you tried some extra fans on the radiators?

[NO_H2O]

I think I would try something on the underside too. Might need some type of water trap/drain in the plumbing.

[Panelfantastic]

Thanks everybody. You all went the direction I was thinking too, underneath.
My bus isn't actually that low... no, really it isn't compared to some of the slammers I've seen, so I've got good clearance under there. Is the air any good? I can screen against debris and don't plan to do any wet weather driving so I think it is do-able.
I will work up some ducting ideas this week and see what fits... stay tuned .


EDIT:
Some things I forgot to add,
I'm running a pair of the largest fans I can fit, they do their job, it will idle at 180 degrees all day, there's just not enough fresh air coming in at speed.
The rad I'm using is four times the size that comes with an Ecotec, when you have enough air flowing, it runs 160-170 degrees even on a hot day.
They make duct fans for the NACAs but they're not worth it, they pull over 3 amps each and only put out 140 cfm...
I do have the windshield vent but it doesn't work/is blocked with the safaris open and that's how I ride 99% of the time...

[yetibone]

Yeah, the air's fine under there, just as long as you get it from in front of the engine compartment. Screen out any debris.

[crewcab1964]

My buddy and I were reading through your dilema. There's a bunch of good suggestions from other people in the forum. I'm sure you don't want to deface your vehicle anymore than you have to. These were some of our observations.

1. At idle, no problem
2. At speed, problem-This may be due to the characteristics of the bus,
when you are pushing through the wind, you are displacing the wind in a
turbulent manner around the bus, not enabling your ducts to work
properly. Even if the air is flowing across the ducts it could be creating a
vacuum, starving the cooling air to the radiators by reversing the airflow
like a venturi. The closest thing we could describe it as is a sandblaster,
compressed air passes at high speed across an orifice picking up sand for
desired affect.

The wind tunnel idea is good. If you don't have access to a wind tunnel, place streamers (construction marking tape) around the ducts and radiator louvers and have someone follow you and video tape you at speed to note how the streamers react. If they push in towards the back you may have to reverse the route of the air to the radiator.

[Panelfantastic]

Crew hits on probably what I think is the biggest problem...
Any of you guys that have ever had a van or SUV knows what that back window looks like after a few weeks with no bath... absolutely filthy! The air just swirls back there, I'm probably getting a ton of turbulent air across the rear right where I'm trying to exhaust my cooling. If it was shooting down that back hatch, it would pull a serious suction on the louvers and my problem would be fixed... BUT, it would take a pro-mod wing to reach up into the airflow and make this happen so that puts me back to bringing in air from underneath. I think NO_H2O is spot on, but I would have to start the chase right behind the front beam, make it almost like a thick belly pan (that would be a plus!) and funnel it down to a couple of round ducts dumping up into the cargo floor. I seriously think that once the cargo area is charged with fresh air, the fans will take over and do it fine without having to run plumbing all the way up to the fans (oh that would look sooooo ugly).


Rich, I sure hope I don't have to start from scratch and move the rad, this is what I get for trying to outsmart you UK guys!

[Steve C]

Hi

Love your bus. A while ago I saw a baywindow with a Subaru motor in it, he had a radiator mounted flat under the belly of the car. Loking at your setup, if the heated air just went down over your motor and out under the rear bumper you would get more flow I feel, like when you have an oil leak on a bus it ends up all over the back window.

Steve C

[Panelfantastic]

Got in late, I'm beat. No pics tonite.
This belly pan/air chase is gonna be the ticket. I did take a few minutes to look under there and this is really the ideal way to go. My duct would be 26 inches wide and 5ft long and 2 inches thick. There is a perfect place right behind the front suspension/tie rods to open the front of the chase up into a mouth that could be 5-6 inches thick without it even being noticable. I can funnel the rear into two 3 inch PVC ducts.
I'm excited again, this idea rocks! Thanks everybody for the support and guidance!
It will take a week or so for me to gather up everything and start working on it... I will report back as it develops.

[kra710]

http://www.franklinsvwwerks.com/images/Eldad9.jpg

I yoinked this off Franklins site, Its a pic of that Ridiculous 23window with the A/C and Porsche 3.6 and....man i hate that bus, makes me mad...I need money