mikes98z

iTrader: (9)

I currently have the stock manifolds with the stock Y pipe and a flowmaster muffler.

I would like to change my setup to mac mid length headers, off road Y and a magnaflow muffler. I take it this will be a night and day difference?

What kind of numbers are we talking about? With a lid and some free mods I ran 14.02 at 98mph. Car has 82K on it and that was with crappy tires. I am getting some new street rubber soon, so that will help.

BTW, car needs a tune real bad.... I have the msd wires and new plugs ready to go on.

Thanks for any opinions and help.
Mike

NOBR8KSS

iTrader: (12)

You should see about a 25 rwhp gain...maybe more if you go with the Magnaflow cat-back rather than just the muffler. PCM tuning should net you some more power over that...may 8-10 rwhp. Opening up the exhaust makes a pretty significant difference on the LS1 cars. Be sure to port the primary tubes on the MACs with a dremel or a grinder...it will help them perform better. I also highly recommend a ceramic coating to make them last a long time and to reduce underhood temps.

You should also expect the exhaust to be significantly louder and less "refined". You should also expect a raspy sound from about 2-2500 rpms.