Project Nissan Silvia - Tech Project

A little over three dollars in 1/4-inch garden sprinkler parts can turn your windshield squirters into an elegant intercooler sprayer.

A little over three dollars in 1/4-inch garden sprinkler parts can turn your windshield sq

Waterflow
The next cooling mod is surely the more effective one. Mitsubishi and Subaru have been putting intercooler and occasionally radiator sprayers on their cars for years now. There's no magic to an intercooler sprayer. It takes heat to evaporate water, so evaporating water sucks heat out of whatever it's near. This phenomenon is why you sweat. Don't believe it? Stick your hand out the window of a moving car and spray some water on it. Cold, huh?

Both Mitsubishi and Subaru use windshield-washer-based systems. A plastic tank and a pump nearly identical to the windshield washer pump are used to make the spray. That, and a fortuitous trip to the garden section of the hardware store gave us an idea. There, we found row upon row of 1/4-inch garden sprinklers in an astounding variety of spray patterns. These sprinklers are connected with 1/4-inch flexible PVC hose, and a huge variety of tees, valves and junctions are available to facilitate your creative routing desires. Amazingly, this PVC hose is nearly the same size as the windshield washer hose.

We bought two 90-degree fan spray nozzles, two tee-fittings, two on/off valves, and a few feet of hose. The first tee divides the windshield washer hose into two, one that goes to the windshield and one that goes to the intercooler. An on/off valve goes in each line, so you can turn off the windshield and turn on the intercooler spray at the track. We then split the intercooler hose with another tee and put one nozzle spraying on the intercooler, and another on the radiator. Mounting the nozzles takes some creativity, and you have to be sure not to mount them lower than the washer tank, or all the fluid will dribble out.

We tested the system at the 100-degree track day for the annual Mt. Shasta All Datsun Meet. Despite the heat, we were able to stay balls-to-the-wall for most of a 20-minute session. Only when the water started running out at the end of the day did the lapping sessions have to be cut short. Now, in most cases, the windshield wipers would be going crazy, so you should unplug the wiper motor at the track. In our case, though, age and crappy wiring have taken care of the problem for us. The intermittent setting doesn't work on our car.

Previous Installments
Hybrid How-To: May 2002
Engine swap, JDM bodywork

* Part I: November 2002
Wheels, tires, brakes, suspension, five-lug hubs

* Part II: June 2003
Disco potato turbo, intercooler, exhaust, engine management

* Part III: September 2003
Shooting for a 12-second quarter mile. Quaife differential, drag tires, clutch.

* Part IV: October 2003
Dialing it in: Whiteline anti-roll bars. Making the right adjustments to pull 1.0g and run a 12.9-second quarter mile with the same setup.