The video below shows the testing I did to see if an intercooler water sprayer is worth the hassle on a fast road daily driven car, in this case the 1.8T project.
Intercooler Sprayer – Setup
Tapped into the hose going to the wipers and routed a new hose with one spray nozzle to the intercooler face. Spray is activated with the washer stalk in the car. It was only a temporary solution for testing.
Testing
Drove the route with the spray and drove the same route again at the same speeds but with the intercooler being sprayed. Differences were logged via video and CarScanner OBD app.
Results
Looked to be around a 2C drop in intake temps with the spray.
Negatives
Having to remember to spray the intercooler
Having to remember to refill water tank
Running hoses and wiring pumps if you are not using the windscreen jets
Intercooler Water Sprayer – Worth It
The intercooler on the 1.8T project is pretty big. On a 36C day the intake temps rarely go more than 48C in fast road use.
Is it worth installing a sprayer on a big intercooler?
I’d say no. A 2 Celsius drop is pretty small.
Worth it on a small intercooler?
I’d say the intake temps will see a bigger drop but you’ll also be having to spray the intercooler more. So again, I’d say the better solution is to upgrade the intercooler. Much less hassle in the long run.
Intercooler Water Spray – Conclusion
All in all I though the results were interesting.
Benefits are pretty marginal on a road car with a properly sized intercooler.
On track it’s possible that spraying becomes a necessity even on a car with a big intercooler. I didn’t test on track so I can’t comment.
But for fast road use, I’d say the best solution for high intake temps is to upgrade the intercooler.
And if you want to reduce the temps even more, I’d say water injection is a better option with the added benefit of water injection upping the octane rating of the air fuel mixture.