I’ve worked out a center mount radiator plan, currently fabricating that pieces for it.
Here’s a link to the post with pics
https://www.facebook.com/271781213562344/posts/278171022923363/
And my build page :
https://facebook.com/arrowblau
Got a plan for the front mounted radiator and bumper, I've come up with a design that
(1) find clearance in the front for a radiator that does NOT impinge/protrude into trunk
(2) keeps the spare tire and original gas tank
(3) maintain the structural integrity and safety of the factory bumper
(4) provides a nice, sleek look very reminiscent of the 911 SC/RS bumper
(5) provides scrape protection for the radiator
(6) provides sufficient airflow for the radiator
(7) basically looks factory
The general idea is to retain the existing aluminum bumper, but modify it so it has that sleek 911 SC/RS look, fit the center mounted radiator behind the bumper, and fabricate a new lower valence panel that covers up the radiator.
I'm a big fan of the 911 SC/RS look (see the attached blue and white cars). But the problem is all the existing SC/RS bumpers are just fiberglass covers and provide no impact protection or structural support. The factory aluminum bumper is a very solid piece but is very ugly with the rubber bellows, impact strip, and all that. So, what I'm doing is welding an aluminum strip in the middle to smooth it out, and fabricating and welding a pair of aluminum side pieces onto it that match the SC/RS bumper sides.
The real challenge was finding a way to seal the bumper to the body, as the existing seal is this really ugly wide plastic strip, and the existing strip (usually called a 'smile') does not extend all the way to the back of the fender. Options were to move the bumper about 1/2" up and use fender welting, modify an early style seal strip, or use a Porsche 964 strip. I decided on the 964 style strip as many have used them on SC/RS and IROC bumpers, and it's by far the easiest route. The 964 strip extends all the way to the back of the fender and is a lot thinner than the existing smile. Also, the 964 strip bolts to both the bumper and fender, so it fits tight.
As for radiator fitment, I measured that there is about 35" between the bumper mounting posts, and about 9-10" of height from where I can place the top of the radiator inside the bumper to where it extends down. I don't want to extend it much further down as this would lose ground clearance, and could be dangerous for the radiator. I'll be mounting a center mount radiator directly in front of the nose of the car, and cutting away the back of that to make a duct for the hot air to exist under the car. This approach should create a pretty big pressure difference on both sides of the radiator, also allow me to fit at least one fan behind the radiator. The main advantage, however, is this approach does not impinge into the trunk area, I still keep the trunk and gas tank, and only lose about 3-4" of space in front of the battery. But unlike the RSR style duct, my duct will go around the spare tire on the right, so that I can keep the spare.
Then, I'll be fabricating a chrome moly cage around the radiator to act as both a lower valence support and as a protective cage for the radiator.
I will also be fitting an additional radiator inside the right fender, probably a from a Suzuki TL1000. This radiator core measures 15"(H) x 7-4/5"(W) x 1-1/4"Core Thickness, so it should fit nicely inside the fender well.
The radiators will be plumbed in parallel. This approach will minimize the pressure drop across the radiators, which is vitally important for impeller type pumps. See, impeller pump flow rate drastically drips against a high pressure differential. If you route the radiators in series, you get a very high pressure drop, and pump flow rate drops to a trickle. I will have to put an adjustable flow regulator in each branch and fiddle with them to balance flow between both radiators.
The center radiator will likely be a modified Toyota MR2 radiator. Here, I'll just have to trim a few inches off the bottom, and re-weld the tanks.