Jump to content
Ultimate Subaru Message Board

Exhaust Flow


Recommended Posts

So, this is a rudimentary math sheet I did for flow rates out of a 1.8L engine.

 

https://onedrive.live.com/redir?resid=9CA0A508CEACADDB!1327&authkey=!ACJ41AFMcHkhIuI&ithint=file%2cpdf

 

This doesn't account for expansion or restriction. It is merely a maximum flow for an NA engine.

Turbo charging changes all of these calculations drastically with compression rates and thermal expansion.

But this allows you guys a formula to start with if you want to figure out the best exhaust size for your car.

 

Twitch

 

PS: The stock exhaust on an EA car is about as awful as you can get.

The flow rate of a stock EA exhaust is still creating back pressure in top gear.

Link to comment
Share on other sites

  • 8 months later...

So, I have a 1982 Subaru GL that I am currently doing a restore on. One of the things I want to change, and trust me there is a long list, is exhaust. My plan is to keep the cat in place but rebuild cat back removing the muffler. I was curious if this is a decent idea and if so, what diameter pipe would I experience the best gain with?

Link to comment
Share on other sites

  • 9 months later...

Join the conversation

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

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  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.

 Share

×
×
  • Create New...