Kilroy's 99 TA

I'm getting a set of used Macs (finally!) and I know alot of guys do some tweaking to them, what should I do before putting them on the car?
(these will be with the ORP)

TA_2001

Here is an old thread that I saved.. about
a mod on MAC's

http://ls1info.com/article.php?sid=108

Do the AIR Restrictor Mod as well..

DRGnFLYZ28

Based on what I've read, you can port & smooth out the ports on each primary tube. I've heard they may have some metal in there that hinders flow. I guess a good port match would help.
Oh, and Jet Hot coat them! I had a MAC y-pipe on my 94 Z and the coating was ok but if I did it again, I'd go Jet Hot.

Good luck!

Red99Hawk

iTrader: (1)

[quote]Originally posted by DRGnFLYZ28:
<strong>Based on what I've read, you can port & smooth out the ports on each primary tube. I've heard they may have some metal in there that hinders flow. I guess a good port match would help.
</strong><hr></blockquote>

How much does this porting cost? Im thinking about getting this done on mine...anyone know?

DRGnFLYZ28

I have an air/die grinder and compressor but you can run out and buy a Dremel (pretty cheap) and do it yourself.

2K2 LS1

iTrader: (2)

I ported my set for the 01' basicaly took out most of the inner weld on the primaries. It was pretty sloppy. I don't know what differnece it made, but I am sure it was worth something. Some people modify them to eliminate the air tubes. And alot of people are making their own custom 3" y pipe.

Kilroy's 99 TA

Is it true that with the ORP the headers are really terrible sounding? anything short of putting CATs back on to correct this?

CHRISPY

Install bullets in the Ypipe. You can also expand the collectors or cut them off, extend the collector a little and put in a 3 inch collector. That has picked up 6 or so RWHP on the dyno I think.
Chris

jmX

Ported before/after:
http://jmx.car-audio.net/car/macs.jpg