4.6l 3v Exhaust Only Dyno

Discussion in '2005 - 2009 Specific Tech' started by Jcon, Jun 17, 2013.

  1. There was a mobile dyno in town last Saturday (4/20/13) at the Pepboys Car Show so I put my car on. The car's only performance changes are: Mac longtubes, Mac ProChamber, Bassani Race mufflers, and 4.10 gears.

    The car was dynoed with just 4.10 gears and 87 octane last year (4/21/12) to get a baseline. Stock numbers were 270 RWHP and 292 RWTQ. Dyno below:


    It was then dyno'ed with the above mentioned parts installed and 87 octane again. With exhaust, numbers were 283 RWHP and 296 RWTQ. Dyno below:


    Below is a table of the changes in performance. I made a mistake in the most recent dyno in not having them start at the same RPM so the data is not as accurate as it could be but, the basic story is yes, I lost some low end torque but were the runs to start at the same time, I would expect it to be single or low double digit losses (not 31% as pictured).


    I picked up peak gains of 13rwhp and 4rwtq. Non-peak max gains were 13rwhp and 13rwtq. The average was 3% gain in power across the rpm band from 2,600 to 6,100 rpms.

    Because I didn't ask for the run file from last year (and the shop hasn't sent it to me, only a screen print of the run) I used excel to plot the data so you can see an over lay:


    I knew that most of us knew that a full exhaust isn't going to post major gains by itself but it is a building block for a stronger car. Before now, I never could find a dyno on just these parts (mostly because it just isn't very cost efficient to do a dyno after each round of mods) but here is the proof I was waiting for. So for all of you in the future, you should be able to better determine where to spend money and what to expect from it. Using a 91-93 octane tune would have likely netted me another 5rwhp and 5rwtq but I just remembered that I didn't even think to switch it (although not sure how great a canned 93 tune would have been).

    The next round will be Steeda Charge Motion Delete Plates, Steeda Under Drive Pulleys, WMS High Velocity Intake, and an 87 and 93 octane tune.

    Here is the exhaust only dyno video:

    View: http://www.youtube.com/watch?v=SnOyQDY6-zI