Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

2004 23LSV Fresh air exhaust


Recommended Posts

Hey guys im going to be building my own fresh air exhaust and cant find anywhere what size pipe they use. I have some 3" stainless sitting at the house that i was hoping i could use but if i need bigger then i will get bigger. If anybody has any insight i would greatly appreciate it! Thank you

Link to comment

My theory is that you shouldn't need more cross-sectional area than the intake throat on the throttle body, especially if it is a normally aspirated engine. 

You could argue the need for a bit more area to make up for flow loss around bends, but dumping the exhaust under water will create a lot more back pressure than the loss in the rest of the pipe. 

I probably wouldn't make it any smaller than the throttle body, at least. 

Link to comment

Mine is the same or just slightly larger than size as the holes for the thru-hull exhaust.  Lift up the flapper and measure the ID of the pipe.  

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...