SR22T CHT Temp High

Question: I’m a Cirrus semi-novice (coming from my last aircraft a 2006 G36TN). I went down to APF yesterday from my home base in Ohio and at 16,000 I was unable to keeps temps below 420F with 30” MP and leaned to the cyan line. I had to lower the power and rich up the mixture in order to keep the temps in the operating range.

Is this a normal situation in an SR22T?

Is there a procedure for cruise in the teens and FLs?

Thanks!!

Contrary to a Non-Turbo you should continue to lean further below the cyan mark to reduce temps, not enrich… That’s the difference between turbo and non-turbo :slight_smile:

30" MP sounds you were already below 100% Power, so all you’d normally do is continue to lean even below the cyan line until you get below 1600 TIT and this should then also help cooling down your CHT’s.

Of course “if everything fails” you can always go full rich but I was told full rich only during take-off and climb and that’s about it in a turbo due to the exhaust valves not liking full rich that much…

If you join COPA you’ll have access to thousands of posts about managing your engine and you’ll get much more of a response to posts, as many members do not monitor the Guest forum.

And CHT’s of 420 are a real problem, as it seems you are aware of. You need to keep them at or below 380.

You should have been leaning the mixture not making it richer

I did join COPA I thought?

Welcome. Indeed, your profile shows you joined COPA on April 11. But, this thread got opened in a non-members Guest Forum that a lot of members don’t subscribe to.

An administrator can relocate it for you if you’d prefer to get feedback from other turbo owners.

Hello Edward, fellow turbo owner here. Welcome to COPA! The search bar can be used to access years worth of discussions about anything. On our perspective turbo display, there will be a cyan line that appears as long as MP is about 30.5, and is the target to lean to for lean of peak ops. However this cyan line for the most part is still too rich, and will yield CHT and EGT and TIT too high. Go ahead and lean further. I lean until TIT is 1585 or less (usually 1550 for me). This will result in 360 typically for CHT in cruise. For me, 30.5 MP and 1550 TIT is about 70% power with a 15.5 gph fuel burn. Leaning even further I start to feel roughness around 1535 TIT. Hope this helps!

Also be aware that if you just joined COPA you may have to log out and in again to make the other forums visible.

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Thank you Brian!!

I’ll do that as soon as he reports that he logged out and back in and can see all the forums. Edward?

I was surprised too as it wasn’t made clear to me at airplane pickup, that the cyan mark on the flow meter is close to the hottest CHT and TIT, and that you have to lean much further. Of course that means your percent power drops as you lean too.

If you’re shooting for higher percentages then there may be no way to lean, and rich-of-peak is your only option. And a maintenance shop owner told me that that is not something you want to do often, and to be happy with 75% or so. In my experiments the difference in speed seems to be about 5knots between 85% and 75%. Anyone have better numbers?

The Fuel consumption between 75% and 85% is much more than the speed increase, it’s not worth it. 85% was advertised as being “OK” continuously but I believe the consensus is that 75% continuously power should be about the max for engine longevity. I basically use one of two power settings for cruise:

max cruise 75% @ 15.5-16 gph
econ cruise 65% @ 13.8-14 gph

Both these settings should yield CHT 330-350 and EGT 1530-1550

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I use much the same, but if I want economy cruise I will first set up 15.5 GPH at 2500 RPM and max MP, then pull the throttle back to reduce the power, rather than using the mixture lever to reduce from max to economy cruise.

Reducing the FF only would further lean the mixture, and slightly reduce efficiency. Reducing the MP (with a corresponding automatic reduction in FF) maintains the same mixture.

Correct, I do the same. Throttle back to 2500-2550 at max MAP then around 15.8 to 16 Gph yields around 75% power. For 65% power pull back black lever. Sorry I was not more specific but we do it the same way which is what’s recommended by the TAT supplement.

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In a 22T you always have 2500 RPM - throttling back only reduces MP (and FF obviously)

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Also to be clear, I think we’re mixing advice between T’s and TN’s. Max MAP in the T is 36 at all altitudes. In cruise you set to 30.5 and adjust mixture back. You can of course pull throttle back and reduce MAP to 28 or 29, but, in my bird anyway, this results in a slightly richer mixture, as the TIT’s rise, so I will need to adjust mixture as well if I throttle back.

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As a new Cirrus SR22T owner I can attest that the most confusing thing about these forums for me is the cross-over discussions between T and TN owners. I’ve gone down several rabbit holes in trying to learn more about the Turbo platform only to realize that the time I’ve spent was lost to posts that were really referring to TNs. I’d like to suggest that if someone with TN experience wants to comment on a T thread, or vice versa, they create a separate thread conspicuously marked with the correct designation.

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I agree absolutely on Shane’s Post… T’s and TN’s are super-confusing here … There are also several threads about why TN’s are better or T’s and on the other hand why I’d should rather fly a T instead of a TN to have control over the whole system…

The only common thing on both is - they can fly higher and obviously faster :wink:

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On our old forum from which we recently migrated, it was easier to tell these types of things because just about everyone’s posts included a signature identifying what type of equipment they were flying. This new forum doesn’t allow personal signatures attached to your posts. However the more time you spend on the forums the more overall knowledge you absorb and eventually you’ll be able to quickly discern such things!