What’s the difference with these exhaust manifolds

Reply Subscribe

Thread Tools

Search this Thread

Oct 5, 2025 | 07:30 PM

corymarc.com

Thread Starter

Full Member

iTrader: (2)

Joined: Jul 2006

Posts: 146

Likes: 1

From: Caldwell NJ

What’s the difference with these exhaust manifolds

The manifold on top has a port on the right. Can I use it and just block it off with the gasket? This will be for a stock twin turbo setup. Thanks

Last edited by corymarc.com; Oct 6, 2025 at 06:05 PM.

Oct 6, 2025 | 06:31 PM

Jesturr

Full Member

Joined: Nov 2018

Posts: 199

Likes: 131

From: SF Bay Area

I believe that hole that is present in one of your manifolds but plugged in the other is the EGR pipe. By my research 93 and 94 cars had EGR and will thus need that port. 95 cars ditched EGR.

Oct 6, 2025 | 07:10 PM

corymarc.com

Thread Starter

Full Member

iTrader: (2)

Joined: Jul 2006

Posts: 146

Likes: 1

From: Caldwell NJ

If my egr is deleted can I still use the manifold and block it off with the gasket? Or is more modification in order?

Oct 7, 2025 | 08:16 AM

j9fd3s

Moderator

iTrader: (3)

Joined: Mar 2001

Posts: 31,796

Likes: 3,210

From: https://www2.mazda.com/en/100th/

Quote:

Originally Posted by corymarc.com

If my egr is deleted can I still use the manifold and block it off with the gasket? Or is more modification in order?

you can use the EGR manifold and not do anything, no need to block it.

Oct 7, 2025 | 03:54 PM

DaleClark

RX-7 Bad Ass

iTrader: (56)

Joined: Jan 2002

Posts: 15,622

Likes: 2,723

From: Pensacola, FL

Also possible the non-EGR is a Japanese manifold. JDM cars didn't have EGR.

Dale

Oct 7, 2025 | 10:50 PM

mikejokich

45 yrs of driving My 7's

iTrader: (2)

Joined: Jan 2012

Posts: 525

Likes: 147

From: Alabama

The non-egr is indeed a JDM manifold. I use one on my USDM car. Either one is fine to use on a USDM car. I use the JDM since it theoretically should slightly improve the air flow dynamics due to less turbulence.
Mike