This was a two part exercise. The fender liner vents being the primary exercise and the relacated washer fluid reservior a secondary exercise. First some theory on the fender vents. Cooling with the RX-7 is always a concern. The two means for cooling the rotary inferno are the water based cooling system and the oil lubrication system. The oil lubrication system cools the oil through the use of oil coolers/heat exchangers located in the front corners of the nose. In my case I have an R1 model so have dual oil coolers. These oil coolers are fed by ducts from the nose of the car. However, to get good air flow through the oil coolers there must be good flow in and good flow out. The flow in is good, but if you have ever removed the fender liners you will note that the oil cooler auirflwo exit is completely blocked by the coolant overflow tank on the passenger side and the washer fluid tank on the drivers side. Mazda did have the principle at least when they designed into the fender liner a duct to move the airflow up and over the wheel arch and out that small vent behind the front wheels. However this duct is small and the path is tortuous and far from direct.

Fender liner oil cooler vent - passenger side

Closeup showing the relative location of the oil cooler.
Note the position of the coolant overflow tank directly in the airflow path.
The logical solution is to simply cut a hole in the fnder liner to vent the oil cooler exhaust air directly into the wheelwell. But I was concerned with the aerodynamics of the flow and what pressures this kind of flow might see, i.e., would it be worse with a hole in the liner than if I relied upon Mazda's up and over the wheel ducting? The I noticed the Mitsubishi Eclipse GSX that has and IC located where my oil cooler is, has a vented fender liner behind the IC. ANd then there was the Nissan Silvia with the IC in the same location. Again the fender liner was vented. And the nail in the coffin was the vented fender liners I saw on a Lamborghini Diablo. Grnated the aerodynamics of all these vehicles is undoubtely different but not that different. So with dremel tool in hand I hacked a hole in each fender liner directly behind the oil coolers and lined then with aluminum mesh. In addition I removed the washer fluid reservior completely and decided upon relocation of a smaller reservior somewhere more out of the way. The side beneft of removing the reservior is there is no longer a heavy gallon of fluid hanging out over the front bumper - bad for weight distribution and polar moment of enertia. Unfortunately the coolant reservior remained as there is no other location for a tank of needed comperable size to the stock tank.
Being the obsessive compulsive anal type car guy that I am I just had to do something about the washer fluid reservior removal...or lack of reservior. So I decided to make a "minitank" for emergency use only. Several issues arose; 1) find a suitably sized tank, 2) find a clear tank and with wall thickness strong enough to support the OE pump, and 3) find a location to put the new minitank. After walking through every tupperware and plastic storage container aisle in every local department store I finally find something I could use. A Tums bottle. Yes the antacid tablets. Perfect size bottle with clear walls, and a wide top opening, made of thick plastic, with no imprinted lettering in the plastic and it came with a nice plain yellow cap. Whew! The stock pump was removed from the stock tank and I noted it was simply press fit into a hole with a rubber grommet. So I cut a hole in the side of my Tums bottle and did the same. FIlled it with water and there it sat on my workbench leaktight for a week. Problem 1) and 2) taken car of.

Tums bottle with OE washer fluid pump still full of water after
a week on my workbench.

Aluminum Minitank Bracket
Now the question was where to put the new minitank? Since the hose for the washer squirters is routed down past the firewall on the drivers side, and since I have no cruise control actuator in this location I had found a suitable spot for the minitank. I determind that a bracket to mount the minitank could be fabricated and bolted to the same mounting point as the ignitor with suitable hardare. The wiring for the OE washer fluid pump was extended to reach the new location whiel the fender liners were removed and the old washer fluid hose was removed and cut top the new shortened length. Then it was time to develop a bracket for the tank. For the steps on how I fabricate aluminum hardware using ordinary mechanics tools click here I ended up fabricating a simple bucket out of aluminum (polished of course) that the tank sits in with a big zip tie to a prong on the top of the bracket that holds the top of the tank in place. Plug in OE harness, connect hose, fill with washer fluid and viola. One mini washer fluid reservior that is lighter and smaller than the OE container and which doesn't block oil cooler airflow. If only I could do the same for the coolant reservior
And in closing I'd like to say that yes I probably am nuts for going the the exercise of making a functioning mini washer fluid reservior but then again it was a challenge and I felt a need to keep my car complete. If this were a race car things would be different but my car is still a street car (a loose interpretation of the term I know). As we have heard before why does man climb Mount Everest? Because it's there. Why did I make a minwasher fluid reservior? Because I could.




This page last updated June 19, 2002
rotorphiles have visited this page since June 19, 2002

If you would like to contact me and converse about my experiences with my 7: please feel free to send an e-mail to crispyrx7@yahoo.com

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