As most of you know, we bought our Challenger for the sole purpose of installing products we offer. What better way to get feedback on new parts than to use them yourself. There is no doubt the car is a blast to drive in it's stock form but as with all vehicles there is still room for improvement.
During the short time we have had the Challenger we decided to do modify it just like the average gear-head would without breaking the bank. First we installed the Mac Cold Air Intake system on the car to increase airflow in to the engine. On the newer cars, the factory sets the computer "tune" for all of the factory equipment. Any changes made can alter these parameters. Case in point when a cold air kit is installed on these cars it tends to allow the air / fuel ratio to run on the lean side. To compensate for this it is recomended to install an aftermarket tune that allows you to make changes to the computer for any upgrades you might add. We chose the Diablo Sport Tuner that has pre-loaded performance tunes for cold air kits, as well as different fuel octane levels that are available. After that we decided it needed some changes in the sound department so we took it to the exhaust shop and installed a set of Jones Full Boar Performance Mufflers. Last but not least we swapped the rearend gears out to a set of Richmond Gear 3.55's. This modification really made the car feel totally different. It drastically improved the accelleration of the car, so much in fact we decided to take it to the track.
The only baseline we had to go from was the on-board Performance monitor that we nicknamed the "dreamometer" we did this because there are factors that don't make it entirely accurate. The best time we previously recorded was 13.75 @ 108 mph with a tune and cold air kit. Given, the dreamometer isn't 100% accurate, but it is still close. We then took it to the local track to get a more accurate time and to see how well she performed.
The first run was done straight off the highway after a 30-45 minute drive. We rolled through the gate, got our number then drove up to the starting line. Off idle she clicked off a 13.41 @ 106 but then realized the guy driving didn't turn off the traction control. Definately room for improvement. We changed the tires to a set of drag radials and decided to give it another shot. The driver went back to the line and "traction control off this time" did a good burnout to heat the tires up. He went to the line and left off idle again and the time dropped to a 13.38 still not what we were expecting. There have been reports of stock cars running these times so we started tweaking on it a little bit. Here is the 13.38 pass
We did numerous runs changing tunes and launch techniques to see if it would better the times but werent having any luck. By this time the engine was getting heat soaked so we decided to park it for a bit and let it cool back down while we enjoyed the races. As time went by, we decided to make a final attempt at a good time before we called it quits for the night. There is always that one person that can get faster times out of cars than any others in your group, so we called upon that guy to make the next run. He went to the line without doing a burnout and left off of idle as well. 13.31 @ 104.2 this was the best run of the night. On that last run he said the car was acting funny, like it was holding back power. We came to the conclusion that even with changing tire size in the tuner, the different diameter tires on the back still affected the speed sensors and the computer tried to compensate. With the factory tires on it the dreamometer said it ran a 12.9 @105.3 The only way to know for sure is to take it to the track again and run it on correct size tires. We'll have to save that for another time though. Needless to say the car is ALOT more fun to drive with the modifications, and there is a definate difference in its accelleration. Spirited driving sessions are proof enough for us that the car is a strong performer and could handle its own if the situation arose.