Torque for Android, combined with an OBD2 code scanner is a great tool for all sorts of things. Among them is checking air intake temperature. While hooked up and driving along on a 110+ degree day here in Vegas, I checked the intake temps. Even on the freeway with plenty of airflow, it was a solid 150 degrees, on the FREEWAY! This is turbo car territory and frankly, it would be a little odd having an intercooler on an Rx8.
After reading through some posts on Rx8club and some internet searching, it led me to some posts where others are having the same issue. The short version of the notes is to install something like the Racing Beat Air Duct. I’ll say right now that based on my testing, this is a good buy.
One of the problems is the VFAD which stands for Variable Flow Intake Duct. This is a nice little piece that opens up a valve to essentially double the intake diameter. When it’s closed, it pulls air from a warm spot behind the bumper.
The update I made basically uses a different intake tube to pick up air in a slightly different location. Now that it’s back together and running again, I think I would actually have better results if I left the VFAD hooked up since the primary air pickup is lower. Also, when I get a chance to update it, I plan on moving the pickup a little forward. A great way to test this is with the car idling and the fans on. The intake should be where the air is still cool.
Results: Highly recommend it. While there can still be a 40 degree spread between the outside air and the intake air, it’s overall much better. Prior to doing this, I would not be able to get close to the ambient air once the car was warmed up. Now it’s about 15 degrees over in flowing traffic and 25 to 30 degrees over in heavy stop and go in town traffic.
Airbox Mod Round 2. Ever since doing this, I wanted to make some additional changes which are shown below.
- Hook VFAD back up, allowing the main pickup to be the relocated intake
- Move the pickup tube forward a little so its out of the turbulent air produced by the radiator fans
Results: With the pickup moved, I now see the following temperature differences.
- Stop and Go Traffic – Intake temps are usually 20-25 degrees higher than ambient.
- Free flowing Traffic – Intake temps are usually 10-15 degrees higher than ambient
- Freeway – Intake temps are usually ambient to 5 degrees higher than ambient
Now for the pictures