Stock and De-catted Head Pipe Temperature Comparison

[bugdewde]

Temps taken after an 8 mile ride.

Here's the stock exhaust:

Here's the De-catted head pipe:

Not a huge difference in temperatures at this point.... after an 8 mile ride while idling in garage.

Rear Head/Pipe:
stock: 350-400
no cat: 350-370

Rear Heat shield:
stock: 120-130
no cat: 115-120

Front Head/Pipe:
stock: 350-400
no cat: 330-400

Front Heat Shield:
stock: 115-117
no cat: 105-112

Transmission cover area:
stock heat shield: 130-210
no cat heat shield: 105-120

 

[Mandrew]

Interesting. I've heard people talk about how much cooler their ride is after removing the cat, but I wouldn't think you would notice a difference between 370 degrees and 400 degrees... Unless you're baking chocolate chip cookies- then you'll notice the burnt taste.


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[wildchld]

The Cat as you ride or even in a car heats up to burn off gasses. Temp of a Cat can reach temp 1600 deg F. So that sucker is red hot once your riding down the road.

Catalytic converters...

•	Are a chemical reactor that use chemical reactions to theoretically change toxic emissions into less harmful emissions
•	DO NOT begin to work until their temperature exceeds 290°C (550°F)
•	MUST reach their optimum operating temperature of 430°C (806°F) needed to reduce toxic emissions

 

[Mandrew]

So, actual operating temp is much higher than the recorded 400?


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[buckshot85]

Butt thermometer is more accurate on the road.

 

[bugdewde]

Economics

Economics

Cats get super hot to render the hazardous emissions less hazardous by superheating them and passing over the precious metals/catalyst in the converter. I'm all about reducing emissions but I also want to be comfortable. It is entirely too hot.

I bought this de-catted head pipe in attempts to lower the exhaust temps on my passenger's right foot. She routinely has to put her foot up on my leg/lap to get heat relief.
I took temps just after an 8 mile ride/loop. I'm sure the temps of the cat are much hotter with rpm and throttle load than what are shown in my initial vid.
While this didn't show a huge reduction in temperatures, I'm thinking it will be much cooler on her foot in future rides where rpm and throttle load are present... since there isn't a catalyst getting super hot right there.

I purchased this de-cat headpipe as an ECONOMICAL step towards cooling my passenger's right foot. It was $135 shipped to my door off eBay. I still have my stock one for future use if needed.
________________________________________________________________________
I have some B&E Performance Max 2 modified stock mufflers on the way. These are also an ECONOMICAL step towards attaining that cool Harley sound without being too loud. I was going with some Screamin' Eagle mufflers (loved them on my '01 Police Bike) but for the money, I couldn't pass up on the B&E Performance mufflers. $135 shipped to my door. And I'll still have stock mufflers for future use if needed.
________________________________________________________________________

As for tuning..... I've read where richening up the A/F ratio will help with cooling, as the stock Harley tune is quite lean.
I will cross that bridge soon.....

 

[bugdewde]

So, actual operating temp is much higher than the recorded 400?


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Oh yes.... much higher I would imagine. Cats are designed to get super red hot during use. Lots of info on the web about catalyst operation.
As stated, they can exceed 1000 degrees easily.

Not sure about my Harley, but typically on cars (my '05 Jeep Rubicon for sure) the exhaust temperature before the cat is 350 degrees. Right after the cat, the exhaust temp is 450 degrees.... while idling in the driveway. I'm sure it gets much hotter while driving... 'cause I can feel it in the floor... No carpet!!!
That's what cats do, they superheat the exhaust (in this case, at least 100 degrees over the incoming exhaust temp) in order for the precious metals in the cat to react chemically with the emissions to reduce their hazards.

 

[bugdewde]

Describes the operation of a cat.
approximately at 2:10 it starts to describe the cat as a "furnace"... which gets up to 1300 degrees.

 

[bugdewde]

Forgot the vid of how it sounds de-catted.

 

[Aviator5456]

Some years back I had a late model new (mid 90's) car and took it to have it smogged, in SoCal. I had been driving it for a time and it failed. When I asked the tech, he told me I need to bring it in within 15 minutes of starting it, because thats about how long it takes to get it up to temps. He also told me that after it reaches a certain temp, there is a temp controlled bypass to prevent the cat from overheating. When I decatted my pipes on my SGS, I didn't see anything like that but that was 20 year old technology.

 

[bugdewde]

Prior to receiving my re-cored/baffled stock mufflers (B&E Performance Max 2), we went on a 120 mile ride. It was in excess of 90 degrees today. She only had to prop her foot on my leg once. I could tell it was cooler than before, but it did get hot.

Maybe a tuner is needed to fatten up the mixture.

 

[2010bsisurvivors]

Need advice on how to reduce the heat on wife's right foot. She tries to move it best she can, but on my 2017 FLHXS, the heat is so bad it has melted the sole off her HD boot. Would also like to know of anyone having heat issues had any luck with adjustable foot pegs and foot boards helping with this issue.

 

[NGOT8R]

Need advice on how to reduce the heat on wife's right foot. She tries to move it best she can, but on my 2017 FLHXS, the heat is so bad it has melted the sole off her HD boot. Would also like to know of anyone having heat issues had any luck with adjustable foot pegs and foot boards helping with this issue.

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