Dyno-might!


On Saturday, I took “Devoted Dan” (my car) to Mavrik Motorsports (www.mavrikmotorsports.com) in Fullerton, CA to get “tuned” by Jon from HB Speed (he used to work for Harman Motive and Surgeline Tuning).  I wanted to get the car “tuned” because the engine was pinging/knocking/detonating when it was running on a Stage 1 engine map (for those unfamiliar with automotive terminology, pinging is BAD for your vehicle’s engine – sound clip here).  No, that engine map isn’t something that came with the car.  I got it when I purchased and installed a COBB (www.cobbtuning.com) AccessPORT for the car in April 2005.

Upon reading stock 2004 WRX engines were experiencing detonation during the closed loop to open loop transition, I wanted to make sure that issue wouldn’t ail my car.  I guess you all weren’t going to buy that anyway.  Yes, having an AccessPORT also helps the engine produce more power.  The AccessPORT allows me to “flash” different engine maps to the car’s engine control unit (ECU).  From April 2005 to mid-2007, I was able to use the Stage 1 91 octane engine map without any problems (read: pinging).  In mid-2007, pinging started to rear its ugly head and I switched to a Stage 1 91 octane California/Arizona/Nevada gasoline map.  Because the fuel in California is terrible, a more conservative map was developed.

General WRX/WRX STI Stages of Tune
Stage 1 – Stock powertrain with ECU reflash
Stage 2 – Modified turbo-back exhaust (TBE = downpipe and cat-back exhaust)
Stage 2.5 – Stage 2 plus upgraded turbo and fuel injectors

A couple months passed and I started hearing pinging from the engine again.  If you didn’t listen to the soud clip hyperlinked above, the best way to describe the sound of pinging would be to imagine the sound of a BB hitting a tin can.  Using higher octane fuel such as the 100 octane gasoline I mixed into the fuel tank before I heading up to Laguna Seca is one possible solution.  The problem with that is gas with an octane rating greater than 91 isn’t readily available.  It definitely would not be worth my time and money (100 oct is around $6/gallon) to find some on a regular basis.  I also tried using some Gumout Fuel System Cleaner to no avail.

Down to my last straw, I reverted the ECU back to the stock engine map.  As a result, I had a lot less fun with the car because there was less low-RPM torque and high-end horsepower.  Being accustomed to how the car felt in its Stage 1 state, I had to slightly alter my driving style to accomodate the loss of power (~15-20 horsepower).  Discontent with the car at stock power levels, I knew my only other option was to get a Stage 1 Protune.  Why only Stage 1?  My car’s only “power” modifications are a Prodrive silicone intercooler hose and a Prodrive muffler.  I also want to keep all three catalytic converters on the car so it would stay smog-legal.  I don’t want to bother with modifying the exhaust and reverting it to stock just for smog tests in the future.


When a person is sick, he or she goes to the doctor.  When a car is sick, it goes to a mechanic.  Given the nature of my car’s condition, it couldn’t go to any general mechanic; it needed to see a specialist.  That’s where Jon, the tuner, comes into the picture.  “Protuning” is the process of developing a custom engine map for the AccessPORT.  Jon started with COBB’s Stage 1 off-the-shelf (OTS) map which the engine was pinging on earlier as a baseline.  From there, he tweaked timing, boost, and other settings to create an engine map that would produce the optimal amount of power with a safe air-to-fuel ratio (AFR) throughout the powerband.  If I remember correctly, it took Jon six dyno, which is short for dynamometer, runs to develop a map he and the car were happy with.

Here is Dan’s clean bill of health (I hope!)!  I was hoping the car would put down 190-200 hp to the wheels.  Even though it didn’t, I’m not disappointed with the result because I know California has “crummy” (insert other choice word here if you like) gas.  I was also told that the dyno used shows corrected numbers that are more conservative than a lot of other dynos.
Dyno Sheet

But wait!  There’s more!  Here are some videos of my car puking its guts out. j/k




Here’s a video of Jon driving by after he was done with the “hard” work.  Isn’t the exhaust note wonderful?!

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About USCTrojan4JC

God Follower, husband, father, USC Trojan alumnus, Mazda employee

2 responses to “Dyno-might!”

  1. banilla777 says :

    i’m glad you finally got dyno tuned. =) i got dyno ecutek’ed 2 years ago, never had any problems with it at all, even in 117F weather. 2 years ago, cobb ap stage 1 maps were pulling less power than stock. lol. i seriously hope they didn’t try fixing the less power thing by running at unsafe lean levels. especially since CA gas sucks. i just got my ap racing 4 pots and rear brembos installed. getting ready for the track in march.

  2. Anonymous says :

    you spend too much time and money on your car. it prolongs your moving out of home by 6 months.

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