I got a set of edlebrock ceramic coated headers and I volant cold air intake. I plan to install them tomorrow. I will give the info tomorrow of the increases. I plan to test 0-60, 46-65 times, and fuel milage on cruise at a set speed. If any other testing without dyno is wanted (I have no dyno access without cost) please let me know by 7 am monday.

 

ive already got the cold air intake and flows, i just wanna know how loud the headers are outside and inside the cab. thanks

 

Ok here it is. O-60 times dropped by about 0.2 seconds and 45-65 times dropped by 0.5 seconds. You can feel faster throttle response, and it throws you back in the seat more. At idle and cruising speed there is no increase in noise. But at moderate to heavy accelerationis is alot louder. Gives a deep growl as my buddy stated it. I was not able to get a good fuel milage test after the install due to traffic, but what I did see was higher. I will get a better test tomorrow. Also I expect to see bigger gains when I can retest at same ambient temperature (was 10 degrees higher after install). There are also some small fitment issues with the headers, but easily solved. I will post these with pictures when I can. No issues at all with the intake install.

 

NOT TO BAD SMOKE. I REALLY LIKE THE EDELBROCK HEADERS. ANYWAYS GOOD LUCK MAN, AND KEEP US POSTED ON NEW RESULTS. HAPPY HOLIDAYS

 

Happy holidays to you as well. I will post the info as soon as possible.

 

Excuse my ignorance, but replacing the stock exhaust manifolds with aftermarket headers will increase fuel efficiency? I have a '98 Z71 and I would like to do some mods, but I dont want to kill my mileage. I have already put a cold air intake on there.

 

Yes it will increase milage. My current gains are about 3 MPG, but it will increase more when I get a good test. Right now I can't keep myself from gunning it now and then. The way it increases fuel efficiency is by creating less backpressure and less turbulance. Headers have seperate pipes that push exhaust in and oderly fashion to your collector then through the exhaust system, as opposed to stock manifolds which throw it all into 1 chamber and let the exhaust try to push its way out with all the exhaust from the other cylinders.

 

Is it worth replacing the intake manifold?

 

Yes, but not till later. You can only put soo much air and fuel in if it cannot also get out, so you may not notice much of an increase till you fix the exhaust side. I cold air intake will generally be enough to get you started. Once you complete the exhaust it can be intake and head time. Then you can move to cam. I like to wait to last for cam so you know exactly what you have and don't have to change cams later if you changed plans (and that will happen alot).

 

Little more update:

My MPG seems to have increased by 3.5-4 mpg minimum. I have not been able to do a good cruise test like I did on install day, but I usually average 16.5 mpg going to work and back (with a heavy foot), and since the install I have been averaging 20.5. I drive 22 miles to work, up 2 high bridges and an interstate change with 3 of those miles in town. The best I have ever gotten is 25.7 mpg at 65 without cruise and used to average 22.5 and these were before the install. I will let you know what I get when I can repeat these tests.