casuprock
10+ Year Contributor
- 320
- 3
- Apr 13, 2010
-
Exeter,
New Hampshire
I'm posting this information to start a discussion about rear mount radiator relocation in the DSM. My particular application is a complete rebuild, but the discussion may be applicable to those retaining the stock body.
Pros
Relocation of the front mount radiator to the rear of the vehicle is better for weight distribution in vehicles with significant lightening of the rear. It is also better for air flow in the engine bay. Vehicles with body modifications can employ an under body diffuser to channel air through the radiator. The radiator is thermally more efficient and does not pick up heat from FMIC or oil coolers. The radiator is protected from debris and snow pack.
Cons
It adds more pressure head to the water pump. It adds negligible mass to the vehicle. It increases the polar moment of inertia of the vehicle. Custom fabrication work is required for airflow and the fabricator needs an understanding of aerodynamics and possibly CFD.
I have a car that is undergoing significant lightening, with many structural and non structural components being replaced by composite materials. Here is a photo of the recently finished trunk (spare tire well is cut out and replaced with cf floor). The radiator will go to the rear of the fuel cell and a diffuser is being constructed to draw air from under the vehicle and out the rear.
To address the cons of a rear-mount radiator, here are calculations that describe both the pressure head on the water pump and added mass from potential rear-mounting of the radiator.
As can be seen, the coolant hose diameter plays a role, and the diameter can be chosen to balance head loss and added water mass to the vehicle. According to the numbers, it looks like a good idea if it is done correctly. If you've had experience with rear mount radiators, please provide insights or data you may have about performance.
Pros
Relocation of the front mount radiator to the rear of the vehicle is better for weight distribution in vehicles with significant lightening of the rear. It is also better for air flow in the engine bay. Vehicles with body modifications can employ an under body diffuser to channel air through the radiator. The radiator is thermally more efficient and does not pick up heat from FMIC or oil coolers. The radiator is protected from debris and snow pack.
Cons
It adds more pressure head to the water pump. It adds negligible mass to the vehicle. It increases the polar moment of inertia of the vehicle. Custom fabrication work is required for airflow and the fabricator needs an understanding of aerodynamics and possibly CFD.
I have a car that is undergoing significant lightening, with many structural and non structural components being replaced by composite materials. Here is a photo of the recently finished trunk (spare tire well is cut out and replaced with cf floor). The radiator will go to the rear of the fuel cell and a diffuser is being constructed to draw air from under the vehicle and out the rear.
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To address the cons of a rear-mount radiator, here are calculations that describe both the pressure head on the water pump and added mass from potential rear-mounting of the radiator.
You must be logged in to view this image or video.
As can be seen, the coolant hose diameter plays a role, and the diameter can be chosen to balance head loss and added water mass to the vehicle. According to the numbers, it looks like a good idea if it is done correctly. If you've had experience with rear mount radiators, please provide insights or data you may have about performance.
.
). Contour from the radiator frame to the vehicle's complex curved shape was a challenging fiberglass job but it turned out great! 
Everywhere else carbon appears in this car, it's either to save weight or to improve function. I should follow my own rules and keep it that way!
