Would they even help me at all? Car is stock aside from a lid. SLP catback and Brian Herta tuning will be done soon.

Would they give me any improvement? Thanks!

 

Anything is better than stock manifolds...I say go for it, with tuning 15-20 hp at least.

 

F that S...Those Macs give 18-20 bolted on, tuned expect 22-25 RWHP with that catback

 

when i put my macs on my ws6 i felt that it pulled alot harder

 

Cool, I think I'll snag them up.

Now, I'm new to 4thgens. What else is needed for the header install aside from the y-pipe? What should I do about all the O2 sensors? Do I need to extend the wires? I did a search but couldn't find out much info. I'm used to thirdgens with one O2 sensor

Any other parts I might need let me know.

Also, should I spend the $$ on a MAC y-pipe? I'm keeping the cats because of emissions testing...plus these MAC's I'm looking at have the EGR and AIR pump hookup. I DO have a connection at an exhaust shop that I assume could fab up a y-pipe.

Thanks guys, thanks for helping a newbie

 

i would advise lt's especially if you plan to cam it later. these cars love to breathe. you'll most likely see slightly better gains with LT's and they allow more airflow. but if you are set on macs they are great as well, well made.

now, youll need 02 extensions that is for sure. Header gaskets, bolts, air tube gaskets and egr gaskets, 02 simulators are all optional. If you install yourself, and worry about breaking something, then get the extra stuff that worries you most. Why not get teh MAC y pipe, itll fit perfectly? now for the rear 02's you have the 2 options: 02 simulators or delete them through tuning. I'm having mine deleted rather than paying 80 bones on something to trick my computer.02 smiulators are for REAR 02 USE ONLY. you can decide from there

i hope this helps, any other questions you can feel free to ask me, or just post up here

 

I put on the MAC's, if i could do it agian i would go with coated LT's. The coating on the MAC's lasts about 2 - 3 weeks. I think it is just silver spray paint. I also could feel the car pull harder with the headers, I have the ory, which RASPS like hell at 2300-2600, going to run 2.5 tru-duals

 

I got 12 RWHP and a ton of torque with mac headers,mac cats,mac y pipe and no tune. Sounds healthier too. One of the best mods I've done yet.

 

What kind of gaskets would you recommend?

 

Stock gaskets. I've reused stock header gaskets AND bolts 90% of the time and haven't had a car come back yet.

 

stock GM exhaust manifold gaskets 12558573

 

K, thanks!

 

Not seeing a listing for the MAC y-pipe for cats on their site

 

http://www.macperformance.com/store/...ategory_ID=569

I'd suggest against getting the MAC Y-pipe with cats...they will restrict flow too much. I'd say get the OR/Y and get yourself a good set of high flow cats.

If you really want the Y with cats check out the sponsors like Thunder Racing, they have them on their web page.

 

You can put cats on the offroad ypipe then? I just ***umed that you just slapped on the ypipe as is.

 

It can be done, it has been done. The OR/Y would have to be cut and the cats welded in. I'd just say screw the cats , unless you have emissions to deal with.

 

I have connections there, I'm just worried about the cops if I get pulled over.

 

big deal if you get pulled over. just hope you dont a repear order on the exhaust.and if so ,your hook up should be able to hook you up again and sign it off

 

I know