So this isn't a Honda, I know, but there are some creative minds and some pretty advanced engineers that I see posting on here so I'll give this a try!

Here's my dilemma:

I'm building a '68 510 with a big turbo motor, wide body, semi-tube frame, ect. I wanted to get a little wild[er] with it so I'm going like the old Audi S1 and putting the cooling system in the trunk.

Everything is pretty sorted out except for the ducting to get air to the radiator! I have 2 options for the radiator mounting position, but that's not the important part, the biggest problem is getting fresh air back there!

I know the usual rule of thumb is to get a little over 1/4 your heat exchanger's surface area in ducting area, but I figure I need a bit more than this (maybe 1/2-1/1?) to make up for the pipes and other ducting restrictions to get the air to the rear.

I'm pretty set on using the rear windows to duct air somehow. My problem right now is finding an efficient way of turning them into ducts! I think I'll probably need some sort of "grabbing force" with an external scoop since the front windows will likely be taking most of the air away from the rear when down. This honestly isn't a HUGE deal. My designer's block really starts at how to get all that air I just grabbed to go into a round pipe without either turning my window into a parachute, or just let the air go back out the duct entrance.

I don't know if anybody has seen some kind of semi-round BIG duct-- like a surface-mounted brake duct or something, but that must be along the lines of what I need. I know a lot of Honda guys pride themselves in ply wood splitters and hand-make aluminum wings and JB-Welded engine blocks that last 10 years, but this project is going to need something a little more clever and less-kluged than that!

this is the side window I was speaking about... and you can imagine another one of those gaping square wholes in front of it taking all the wind away...

http://farm4.static.flickr.com...g?v=0

http://farm4.static.flickr.com...g?v=0

Here's the view from the inside and you can see the parcel shelf that the pipes will go through. I have 2 8"dia flexible PETE pipes now but can go smaller/larger...

http://farm4.static.flickr.com...g?v=0

http://farm4.static.flickr.com...g?v=0

And here's one reason why the radiator probably shouldn't stay up front...

http://a747.ac-images.myspacec...a.jpg

Please let me know what you guys think and don't discriminate TOO much that thing thing is made in Japan and not in Deutschland! Any help would be greatly appreciated!

 

wuddup Matt! its the other Matt that used to work at turbohoses....

anyways ive seen plenty of rear mounted cooling systems working there (MR2's) even trunk mounted using top mount scoops. They even run the intercoolers on the side rear quarter panels.

as for fresh air getting back there, the problem your going to run into is where is the air gonna exit....

 

O man I have the biggest passion for this type of stuff, unfortunately with my car n work its hard for me to draw up a few ideas. I do however think you need to look at how extreme you want to take the exit air flow.

the mounting position of the radiator should be decided as well. cause you have to remember that due to coll air and hot air flow differently and generate different densities you can actually direct the hotter post radiator air to generate downforce or lift if done right, also look into just custom fabing a plexiglass plenum for each windon(if you ahve the tools to make sure the holes in the windows are large but flush and if cooling is an issue direct the are into it with a small flap on the trunk side of the window.

What types of tools do you have access to and does clear matter to you?.

 

It can be as complicated as you want it to be... Or Not.
Very practical idea for your application but not really new. I have had experience back in the 80's in New Zealand with a similar project... A V8 powered Toyota Starlet. Cooling was the least of our problems!
The ducting of air from the Side windows will be more than suficient to cool a decent sized radiator mounted in the trunk area and exiting out under the rear of the car. Ducting should not be a problem- External Air pressure will easilly feed a well designed ducting system.
Check out my Technical page on http://www.specialprojectsms.com I could probably draw up a workable design.

Kiwi

 

I am currently doing the same thing on my car. I will be running a b18 with 3076 and usual mods but dont have the room for a radiator off good size in the front of this car(daihatsu charade).

So I am doing a rear mount set up for cooling. The feed is will be from a NACA duct on the roof 24 inches wide a 7 inches deep.

The rad core is 28 inches by 16 inches.




The exit will be through the rear hatch.






There is no room for a full length radiator.

 

matt is there any way you can do a V mount setup with the radiator and the intercooler?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">matt is there any way you can do a V mount setup with the radiator and the intercooler? </TD></TR></TABLE>

Not in a 510, unless it's a rotary or has a radical engine set-back...

Why is it you can't fit a radiator up front? That FMIC isn't really that big (far from the biggest I've seen fit in a 510). Why you can't put a good radiator behind it? What sort of engine is going in it? Or are you doing this just for the sake of doing it? It sounds really unnecessary to me...

 

there is a really neat article on net thrust as it relates to cooling in this months sport compact car, for a little different info expanding on what the guy said above