Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Doing a engine back custom exhaust - few Q's

Featured Replies

m doing a full header back custom exhaust in the very near future.

Just getting my parts and info together first.

Im going to have the exhaust shop build my headers.

Since the heads are single port , this should be easy and simple for them.

Is the current exhaust dia. on my 96 2.2L NA 2"?

Should I go 2.25" or 2.5" dia.

I have a cone filter on the car now so this should compliment it well.

Im using a Summit racing turbo muffler and a universal Catco cat , no resonator.

 

Any suggestions or tips.

I added a larger 2.5" exhaust and totally took out the cat on my '90 Legacy (180,000 km) and put on a 'racing' muffler. Other than it being louder, I didn't notice any power difference. Has anyone verified that doing this on a 2.2L NA makes any difference?

  • Author

Well from your amount of gutting I can certainly expect there not to be any bottom end gain.

There is almost zero back pressure on your car now.

Im going w/2.25".

 

I had a 90 2.2L 5spd w/flowmaster 50 , no resonator , 2nd cat delete and it wasnt loud and had better throttle response and low end torque.

There is almost zero back pressure on your car now.

 

That was probably the goal. Low backpressure = more power, as long as the pipe is not so big that it only creates a proper scavenging effect at higher RPM's. That being said, I would think a 2.5" exhaust would be a little big for a 2.2l to develop proper exhaust flow at lower RPM's. The cross-sectional area is just too big. I would think a 60mm exhaust would be good on the 2.2 (slightly larger than the 2.25"), based on the fact that most 1.8-2.0 litre N/A engines are happy with 2.25".

I just went from a 2.5in pipe with out converter or resonator to stock pipe with converter, resonator, and a free flowing muffler and noticed how much low end power I was missing. The 2.2 NA engines seem to like a little back pressure. But now I miss the wake the neibhors piss off old people rally car sound track! Just my 2cents.

Well from your amount of gutting I can certainly expect there not to be any bottom end gain.

There is almost zero back pressure on your car now.

Im going w/2.25".

 

I had a 90 2.2L 5spd w/flowmaster 50 , no resonator , 2nd cat delete and it wasnt loud and had better throttle response and low end torque.

 

 

2nd cat? Are there 2 catalytic converters on U.S. cars?

I just went from a 2.5in pipe with out converter or resonator to stock pipe with converter, resonator, and a free flowing muffler and noticed how much low end power I was missing. The 2.2 NA engines seem to like a little back pressure. But now I miss the wake the neibhors piss off old people rally car sound track! Just my 2cents.

 

The 2.2 NA engine hates backpressure, just like any other 4 stroke engine. What it does like is having the exhaust pulses create a good scavenging effect in the pipe, which does not happen at lower RPM's in a 2.5" system.

I might add that there's a Borla knock-of header on ebay that a lot of people like. Cheap, too.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.