×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Exhaust pressure in 2 wheelers

## Exhaust pressure in 2 wheelers

(OP)
Hai,

I want to know the average pressure in exhaust mufflers of 2 wheeler automobiles at rated rpm.

With Thanks & regards,
Amit
Replies continue below

### RE: Exhaust pressure in 2 wheelers

Backpressures of around 0.6 psi ahead of the cat at full power are regarded as acceptable by our engine people (they aren't happy about it). I think about 1/3 of that is in the cat, and 2/3 in the mufflers. Most of the muffler loss is required to get good subjective acoustic performance, rather than meeting the noise regs.

Cheers

Greg Locock

### RE: Exhaust pressure in 2 wheelers

(OP)
Hai Greglocock,
Thanks.

I have concern about the reply. When I converted the 0.6psi in to bar, it came around 0.04bar(I have taken it as absolute pressure).The atomospheric pressure itself is approximately 1 bar. How the pressure in exhaust muffler can be less than atomspheric pressure. If it is less it may act as suction.
Please excuse me, If i understood things wrongly and then asking a question in completely wrong way.

I can't get cat. What is that cat?

With Regards,
Amit

### RE: Exhaust pressure in 2 wheelers

I'm pretty sure Greg meant 0.6 psi gauge, which is atmospheric plus 0.6 psi or 15.3 absolute.

Blacksmith

### RE: Exhaust pressure in 2 wheelers

(OP)
Hai blacksmith,

Thanks for the clarification.

Cheers,
amit

### RE: Exhaust pressure in 2 wheelers

The "cat" he's talking about is the Catalytic Converter,. a series of ionizing screens that convert gases. Mandated for all cars to meet emissions regulations.

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!