warn me first...

 

I seen this suggested on several forums, and though I do not intend to do this while under warranty, I think it is worthy of discussion.

A catalytic converter doesn't make heat. It uses it for the catalytic process and it has to be HOT. Heat is a function of pressure. PV=NRT where NR are constants so we can go with PV=T.

Without trying to sound to heady, to raise temperature, you have to compress more gas into a smaller volume. HD had to raise increase it compression so the catalytic converter would work. Now it is true that is retains heat and will increase the felt temperature to some degree but the reason these beasts run hot is the high pressure they have to run at. Cutting out the catalytic converter will probably lower some ambient heat simply because there is less mass being heated but your pressure will still be the same and therefore, you engine is still running as hot.
Of course, the upside is that higher pressure engines have more torque.
Old short stroke bikes which had significantly lower pressure ran cooler. In fact, it was still possible to start them with leg muscle. I doubt many of us could kick over an M8.

 

A catalytic converter causes nitrogen compounds and unburned hydrocarbons to be broken down at lower temperatures than would occur at normal engine exhaust temperatures. These are exothermic reactions, so they do make heat. It depends on how well the engine is running, but properly tuned and warmed up, it varies with load, and it is typically between 30 and 100 degrees F at low loads. The converter itself does get hotter as the reactions occur. It has very little to do with pressure. PV=nRT is the Ideal Gas Law for closed systems and doesn't include anything regarding combustion and chemical reactions.

 

How do catalytic converters work? - Explain that Stuff

https://www.explainthatstuff.com/catalyticconverters.html

Jun 10, 2018 - Typically, there are two different catalysts in a catalytic converter: One of them tackles nitrogen oxide pollution using a chemical process called reduction (removing oxygen). ... The othercatalyst works by an opposite chemical process called oxidation (adding oxygen) and turns carbon monoxide into carbon dioxide.

 

While that piston is rising on the compression stroke, the system is closed. How do you think a diesel works?

"One problem is that they only really work at high temperatures (over 300°C/600°F or so)"

 

I know how diesel engines work intimately, thank you. Once you add fuel at the end of compression it's no longer a Closed System, and when combustion occurs the ideal gas laws no longer cover everything.

 

IF you are burning your calf or thigh it is pretty unlikely it is your catalytic converter, which is located under your right foot. Exhaust gas from your rear cylinder hasn't made it to the converter yet. Changing the entire exhaust system or removing the converter won't lower the exhaust gas temperature significantly. The new system MAY have better heat shields.
MOVE YOUR LEG! An inch forward and out will help a lot. If your knees are touching the tank or air cleaner cover your legs are too close to the engine.

 

Some great remedies to leg heat here...I'll just say I hope I'm still riding at 85 !

 

I always find it amusing that some folks, that still have their catalytic converters intact, swear up and down that removing them won't make a noticeable difference.
Once they do remove them, they either proclaim the benefits or go completely silent. lol