Intercooler Fitting
TLDR
- Fitted the intercooler
Details
To fit the intercooler, a bunch of Rotax parts needs to come off the engine and be modified.
Preparing
Before starting, I cut 2 cardboards and placed them on both sides of the intercooler just for protection.
Detach Pop Off Valve
The first thing I needed to do was to pull the pop-off valve from the throttle body. This part wasn’t bad. I needed to take the rubber hose off and cut it to Sling desired dimension. More on this later.
Rotate the Connection Hose 90 Degrees
I didn’t take picture for this step, but there is a 3/4” hose at the bottom of the pop-off valve. Once the pop-off valve is fitting to Sling’s desired location this hose will interfere with the cowling. So Sling instruction said it needs to be rotated 90 degress.
It’s held together with 4 M5 hex bolts. I loosened them and rotated the hose fitting, then re-tightened the bolts to 5nm.
Cutting Hoses
The cutting was honestly pretty nerve-racking. Obviously I don’t want to cut into a brand new engine. But it had to be done. There are a total of 3 hoses to cut, they connect from the throttle body to pop-off valve, then pop-off valve to intercooler outlet, then intercooler inlet to turbo fan.
I followed the dimensions required by Sling, and prepared all hoses to test fit all the pieces. With the first cut, the intercooler fitted reasonably well but a tad too close to the firewall. I made a few more marks on the hose and took everything back to the table to cut again. This process lasted a few more times before the intercooler was well within the desired distance range from the firewall (110mm - 150mm).
Fitting the Shell(?)
On the picture above you will see a composite shell piece around the intercooler. That’s used to glue a rubber seal in front of the intercooler to let cold air in more efficiently.
And because it’s made in fiberglass, of course it didn’t fit on the intercooler. I had to trim one of the four corners to get the shell piece fully lay on top of the intercooler.
Secure the Intercooler
The intercooler is quite solid once the hoses are all connected. But 2 additional spacer are required to ensure the intercooler doesn’t move around. The spacer is essentially just a adel clamp with a angle bracket. It secures the intercooler to the engine mount through the clamp.
As I put on more and more parts on the engine, the accessible is a real issue. The 2 spacers were really difficult to install due the space. Spent ~30 minutes battling against the two spacers.
Wrap Up
The intercooler is installed, hopefully in its final position.
I still need to install the hose clamps, and glue on the seal.
And several wires are touching the large intercooler. I will need to reroute some wires, especially behind the intercooler.