I ordered a cat back kit from Cool Tech
with the hopes of gaining a few more ponies and more importantly a little more torque along with the guaranteed ground clearance improvements.
I had previously installed an Air Raid
intake for the 2007 JK. This allows the engine to get as much air as it wants plus having the benefit of sucking in cooler air with their air chamber. Now I needed to get the engine to release as much air and gases that it wanted to. All in the theory of the better the engine can breathe, both in inhale and exhale, the better it will work with less restriction.
First off I have to say that Cool Tech
has been very supportive and in a previous transaction ordering their CB Antenna Mount
went incredibly smooth and questions were answered with a phone call and even with a defective antenna (not Cool Tech's fault) they replaced it, overnight at no charge to me. So going in to this deal I already knew that the customer service was backing an already well designed kit with complete instructions and once I started the install it would go smooth as silk.
So without hesitation I ordered the Exhaust kit for the 2007 JK
. This kit sells for $299 as of this writing. I need to add that I ordered this kit just before the Easter Jeep Safari and that Cool Tech was planning on attending so they took the time to send out my exhaust kit to make sure I had it before they left for EJS.
One of the things I wanted to do was to see with some sort of proof that the exhaust kit actually did some additional improvements over the stock exhaust with the Air Raid already installed. So I took a little trip down to Mr. Gasket
here in Carson City for a quick run on their dyno. Now you might say that to dyno an off road machine is a little silly and I expected some comments once I arrived at the dyno. Well I am happy to say that what I expected and what I got was two different things. Instead of some snickering I got a lot of questions and comments while quite a few of the employees came out to see this Jeep on the dyno. I did hear one comment of "That doesn't look like a race car" but the guy who made the comment was probably the most impressed with the results and the Jeep in general and was planning on taking the wife down to the dealership for a test drive.
So here is the dyno facility.
And the 2007 Jeep JK sitting on the dyno.
With the Air Raid installed the Jeep dyno'd out pretty good with about 142 hp at the wheels. They even did a negative dyno to see how much of the ponies was being taken to turn the gears and that showed a nearly 20hp reduction which is why the wheel horse power rating is as low as it is.
So on to the install. Cool Tech
instructions came printed on a single sheet of paper with color images. This indicates that the install should be pretty easy and in fact it is. The hardest part is removing the exhaust to install the Cool Tech
The kit consists of a new MagnaFlow
muffler, a new exhaust tip, three muffler clamps and the heat sheild.
I would take a garden hose and a small sprinkler and hose down the underneath of your Jeep to remove mud, dust and debris that would otherwise fall on to you while you are underneath your vehicle installing the exhaust.
In an effort to help this install go easy you should pre-soak the nuts and bolts and soak the rubber exhaust hangers to make the install go smoothly. I use this stuff.
Now Cool Tech's instructions to say to use WD-40 on the bolts which you can use but this stuff I can spray on anything (except finished paint) and it will lubricate just as good if not better. The reason I don't use WD-40 is that it is a lacquer based product and when it dries will leave a lacquered coating on everything that will eventually cause moving parts to not move anymore and more importantly on the exhaust hangers will cause them to dry out sooner and rot away sooner. Another good lubricant is PB Blaster. But I was out of that at the time of this install.
First you loosen the two factory clamps using a 15mm box wrench. The nuts are on top of the exhaust pipes and makes for a lot of little turns to loosen them. There is one clamp right after the cats and one one the factory muffler.
Then you get to remove the rubber exhaust mounts.
I used channel locks to remove these rubber hangers. I open the channel locks to fairly wide jaw then place one set of teeth on the tip of the metal hanger and the other behind the rubber hanger near the center hole. I then just squeeze the channel locks and this forces the rubber exhaust hanger up and onto the tip. Once the hanger is on the tip you can use a small flathead screw driver pushed from the backside of the rubber hanger and down the center hole then with a little pry action the hanger will come off easily. The other option is pure brute strength which works but at the risk of leaving some knuckle skin on the Jeep frame.
Once the hangers are off and the bolts are loose you can start to pull the exhaust out from the Jeep. I first pulled off the enormous muffler off of the main exhaust pipe.
Rocking the muffler or pipe side to side then up and down while applying some pulling force will help you separate the exhaust. You can also use your hand gripped around the smaller piece you are pulling and rock back and forth against your hand to pull more stubborn parts apart. You can also use a hammer to lightly tap on the connected pipes or squirt in some of your lubricant to help break any chemical seal from oxidized parts if the exhaust parts are being really stubborn.
With the exhaust free you need to pull it out from the frame so you can work on it. According to Cool Tech's instructions you can pull the long exhaust from the rear of the vehicle after jacking up the frame to create enough room to pull the pipe.
Remember to use chocks when jacking and use care when lifting a vehicle.