Chris, they aren't that heavy, but they are heavier. I think I remember weighing them at 24lbs for the front and 27-29 for rear.

edit:

according to the tuner, " It lost everywhere, I had to add timing to make up for lost power."

4-5 lbs per wheel plus the extra weight of more tire is pretty significant when it comes to wheel weight. First step in my opinion would be check for vacuum leaks. Especially make sure the seal between the new manifold and lower plenum is good. You torqued the manifold down in the correct sequence correct?

maybe you made nice gains under the curve. looking forward to dynosheets.

That's what I'm hoping too. I still haven't received my dyno run files.

Yes I did, I followed the service manual

IDK lest see what the run files say? Someone say low, I made some pulls on theirs a few weeks back and made 256 WHP and 218 WHTRQ ! We all know that's wrong. Mine was chalked up to they had the dyno set for a full time AWD. :/

How do you like the z1 headers are they worth the money.

I only installed the Z1 manifold. Butt dyno says I got some midrange power, but dyno says my peak numbers didn't move at all. I'm going to call them tomorrow to get my drf files.