hey all,

I have a 2009 chevy Silverado 5.3 V8 I have been researching a lot about adding the Pacesetter headers to my truck. I already have a flowmaster cat back exhaust but I had a couple questions.
1) if I add the headers will the cat converter restrict a lot of the horsepower from them?
2)if I were to remove the cat converter would I need an x or a y pipe? the muffler I have is a single in dual out.
3)how much horsepower would I gain or lose from removing the cat or not removing it?

thanks in advance!

 

If it were me I'd leave a cat in. Buy the headers and Y pipe and you can just weld in a high flow cat if necessary. Really cleans up the sound and takes the rasp out. I personally run no cats but I do run a powerstick muffler in front of my Corsa muffler to tone down the rasp. Really helps with cam and headers. From there any exhaust shop can fab it up with 3" piping.

 

do you have any reccomendations for a high flow cat?

 

Your stock cats are high flow units.

 

anyone recommend a good y pipe?

 

Normally you buy the same brand Ypipe as the headers you purchase. Otherwise you'll be fabricating and or modifying a Ypipe to fit. I bought CalSpeed headers and modified the collectors with a cone engineering kit along with some ball/socket flanges for easy bolt in install. Ended up modifying the hell out of the Ypipe to make up the difference in collectors. Truck sounds bad *** though.

 

There will be no perceptible or significant difference with the cats in place.

 

Im gonna say leave the cats alone or u may don't like the sound im installing some long tube headers right now and gonna leave my cats in there and make my own dual 3 pipe going into an 3" X pipe haven't decide what im gonna get for a mufler maybe a flow master 44 im gonna make tgem 3"in since i can only get 2-1/2 dual in/dual out

I'm running a tr220 cam and i will get a dyno for it so if you go with the long tubes get a dyno yo improve the long tubes in my opinion with LTs headers and a tune you should see some 20-30 engine HP ,,, a cam with long tubes and cusyom cat back you can see 80-100 crank hp gains

 

thanks for the replies guys! I was thinking of going with the pacesetter long tube headers cuz ive heard a lot of good things about them for their price. has anyone heard of any problems with these?

 

Personally I would buy CalSpeed for less money and since it's 304 Stainless.