The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Morrison Fabrications
Please Support STM Tuned

Resolved 1G Port matching FP exhaust manifold to head

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

BoostBolt

Probationary Member
4
0
Apr 16, 2024
Cypress county, AB_Canada
I'm trying to decide whether or not to port match my Fp exhaust manifold to my head.

On the Fp manifold, the port openings are much bigger than the ports on my 1g head.
I'm unable to find a conclusive answer as to whether I should make the ports on the 1g head bigger to match the ports on the Fp manifold.
Here is a picture of the gasket that matches the manifold.
Here is a picture of the gasket sitting on the head to show how much I would have to remove from the head.

Any help would be appreciated.

You must be logged in to view this image or video.


You must be logged in to view this image or video.
 
If it was the other way around, lets just say your manifold had smaller ports than the head, then porting and blending the manifold flange into the size and shape of the head ports is worthwhile. Exhaust gas slamming into an abrupt lip hurts flow and causes turbulence. This is why you see many turbine housing inlets ported and blended to match the exhaust manifold outlet when they're BIGintoSMALL.

But since your head ports are smaller than the manifold ports, the exhaust just exits out pretty cleanly (minus some tiny bit of turbulence around the lip which doesn't affect you materially anyway).

And considering the stock head ports have been proven to over 800hp.. yeah, totally unnecessary to match below that.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top