Part 2 Cooling system upgrades | Mazda Rx7 Turbo
Our turbo convertible is getting two Setrab Oil Coolers / Fan Packs along with cleaning up the airflow to the radiator. When you have a front mount cooler, it is paramount that airflow is taken into account when designing a proper shroud in front of the radiator / AC condenser.
For this vehicle, we do not add in the thermostats for oil coolers, why? It is because the rotary engine is an oil flow motor, yes it takes a few minutes longer to warm up. This is acceptable for a car that is driven with the top down and on days that dictate a solid drive to enjoy the power, handling and comfort that the Rx7 brings.
Why add in two oil coolers?
When you are asking air to flow through the intercooler, then the oil cooler, then the AC and finally the radiator, that is a very large request. Even if the air does pass through all of it, the differential of air temperature (that is what promotes cooling of hot air) is so close to actual conditions, cooling is severely reduced. It is all about the right amount of cooling surface area, pressure drop of the oil coolers and oil volume. This addition adds in 2 more quarts of oil volume, that is a good thing.
OEM coolers with a front mount intercooler may work for sea level performance, add in altitude / hot air and very low air density (the amount of moisture in the air) and you will get high temperature readings, that leads to high engine wear.
Why not go with a V-mount? This was discussed. It all comes down to expectations and how the car is to be driven. A 'V-mount works well when you also add in a vented hood, that creates a negative pressure zone to pull air out on the backside, however adding a different hood takes away from the overall aesthetic of the car. Many of our customers want a clean look that isn't garish. Again, all about expectations / personal preference.
Additional note: We use white painted RV grade aluminum is because if there is a leak, we can easily see it. Yes, black is cool, yet performance wise it absorbs heat and is hard to find small leaks before they become large leaks. Now, the front mounted oil coolers have black painted shrouds because they are visual from the front bumber.
That radiator shroud is bent / riveted and structurally strong with foam sealing up to the radiator for abrasion resistance and proper sealing. Details Matter.
Our focus is to give the motor the right components to cool oil, air charge, and coolant and keep the engine in the safe zone when you need high power output.
This is a common issue for high performance here in Colorado. We are at a high altitude and low air density vs. the rest of the country, make smart decisions about your cooling system, build them right and they will perform when you need them the most.
Driving in the mountains is a trip worthwhile when you have proper cooling for the conditions. Most shops will shy away from the fabrication it takes to properly route air through the cooling system, it is time consuming and having the right bending / cutting equipment.