Rayjay Compressor Discharge Temp

[M20F]

When I put my EI-50 in I did a TIT but for whatever reason I didn't put in a CDT which I am getting added finally. Any suggestions for range for yellow and where to set red at?

Anyone got the math that shows impact of CDT to % of horsepower as well?

Thanks!

[carusoam]

PV=nRT

What you are looking to do is determine the amount of air you can squish into the engine.

Pressure and Volume are key, temperature is a huge variable. Hence the popularity of inter coolers. Compressors generate a lot of heat.

Under NA conditions we measure those with MP and sub in an OAT or DA factor.

The POH or updated POH from an STC will typically print temperature increases/drops to use for what is going into the engine.

TIT is used for protecting the hardware related to the turbo.

CDT is used for protecting the engine from detonation.

Keep in mind that I'm only a PP of a NA plane, not a mechanic...

Best regards,

-a-

[philiplane]

CDT should be below 200 dF for best results. Above that and you get high CHT and run close to the detonation margin, even with 100LL fuel. There are some mods you can do to decrease the engine's inlet air temperature. Add a 1-2" ID blast hose routed from the engine aft baffle, clamped to blow cooling air on the rajay outlet. Adding some finned alumnum heat sink such as that used on oil filters can help. Anything to increase surface area and increase airflow on the outside of the turbo outlet will help dissipate heat. No where near as good as an intercooler, but anything at all helps. The Rajay setup generates higher heat the farther up you climb. Above 15,000 feet is where you can exceed 200dF intake temperatures.