Alright, i want to know has anyone did the extrude hone to there oem intake manifold and got any gains out of it. And comparing the stock cfm to the hone cfm. Just wanted to know cause im trying to build a high response n/a s2k.

 

I just searched the board for "extrude" and the results do not look very promising. One member reported zero gains, though his S was supercharged. Don't know of anyone who was N/A that did it then dynoed to see what they picked up.

 

The stock manifold is very good the way it is. Maybe look into itb's if you have the funds?

 

The stock manifold is garbage man.I'd portmatch the runners to the head and hone the runners and the Plenum.

 

the biggest downfall of the stock manifold is the tiny plenum.. something extrude-honing simply can not fix.

 

You can open up the Plenum a few mm and in the na game every little thing counts.you should know that.you could try some of those bead hones to do the Plenum with so you don't have to cut and reweld it like most suggest.just be mindful of the amount of honing

 

Opening the Plenum a few mm wont help... it needs to have quite a bit of volume added. Not to mention the wall of the the Plenum is less than an inch from the opening to the runners which regardless of volume still restricts flow into the runners