I should have posted this a long time ago but havenít gotten around to it.
I was the first to get the new version of the Avenger supercharger system a while back (https://www.jkowners.com/forum/showthread.php?t=23204
) and wanted to see how much more I can get out of it.
The game plan was to get a smaller pulley and make a little more boost with it. I got a 3 inch diameter pulley which is 3/8 inch smaller than the one that comes with the kit. You can see a side by side comparison of the two below. The one in my hand is the stock pulley that comes with the kit.
We decided that before we throw more boost at the engine, we should alleviate some of the back pressure. The stock headers on 08 wranglers have 4 cats and look pretty restrictive so I opted for the Borla long tube headers. These donít have cats which isnít an issue here in Colorado Springs since we donít have emissions tests. Anyway, I am using them for test purposes only
. Here are some pics:
To protect the spark plug wires, we got some wire boots:
We dynoed just the headers and learned a very shocking fact (shocking to me, since I spent all that $$). The 3.8 likes back pressures. We lost 10 wheel horsepower with the Borla headers. We dynoed it with and without the stock muffler and saw the same numbers.
I emailed Borla several times and never got a response. Overall, I am not satisfied with them and would not recommend these headers. The inside welds were not very clean and they come with felt gaskets which are now leaking
Throwing the smaller pulley on added ~2.5 pounds of boost on average. The extra boost added 13hp and 28tq as measured at the wheels. The dyno graph below shows my stock numbers (pink), stock Avenger numbers (Red), and my new numbers (black). Stage 2 increased my horsepower by ~8% and torque by 14% over the Avenger kit and brought by total gains up to 68% in hp and 78% in torque over stock.
Dotted lines = torque
Solid lines = HP
I have one more power adder that I have done which I will start another thread on.