Installation Time: Full Day
January 19, 2013
Easy install, decent gains, tune required!
These are made out of solid billet aluminum and add an extra 20 grams over the standard cast pieces with the butterfly valves and linkages. They are designed to fit 2005-2008 Mustang GT with the 4.6L 3V V8 engine. 2009-2010 Mustang GT intakes have the valves built into the intake manifold and will require a different product (delete plugs).
A new engine tune/calibration is required because the IMRC/CMCV has to be shut off, and a few other things need to be done to maximize the power gains with these plates. After doing extensive research on these plates, I have found that with a good tune the plates alone will net approximately 10 rwhp gains without any loss of low-end torque/power. There are a lot of discussions going on about the potential for losing low end power, but based on discussions with tuners that I know and reading dyno graphs, the power gains are only positive throughout the engine operating range. The CMCV/IMRC is apparently used only for emissions control, as the new 5.0L DOHC V8 used in the 2011-up Mustang GT does not use any type of IMRC/CMCV and instead has variable cam timing for intake and exhaust valves that most likely do all of the emissions reduction.
The overall installation took about 3-4 hours, mainly because I took it very slowly and had numerous meal and bathroom breaks. My 07 Mustang GT also had about 12k miles, so the intake manifold gaskets (the green silicone/Viton gaskets attached to the valve plates) got really stuck to the cylinder heads and required some additional force to lift out. There was also a lot of dirt and grit to clean out of the engine due.
The LH plate is for the driver’s side, and the RH plate is for the passenger side. I followed TacoBill’s installation guide, which has the best photographs of any online guide I have found. The fuel line does not have to be disconnected, and the air intake tube does not have to be removed either. The air intake tube at the throttle body has to be disconnected though. Also, the vacuum tube on top of the PCV tube simply requires the white tab to be fully depressed to disengage the lock (the tube above the one with green rotating lock tabs).
After installing the plates and my new tune, I did not see any check engine lights or RPM flare up after a cold start. It started up like normal and idled very smoothly. I have not taken it on the road for a test because of the weather (winter in Michigan) but it did not exhibit any problems.
Overall: 5 out of 5 stars, a great modification if you wish to stay naturally aspirated or utilize the stock intake manifold. I originally wanted to buy the Ford Racing intake manifold, but every dyno test of that intake showed significant decrease in power and torque below 5000 RPM with all of the gains well above 5000 RPM. Even with the 3 Stage CNC heads and Hot Rod cams, the Ford Racing intake manifold only showed gains at the 6000-7000 RPM range, and the stock intake manifold provided the largest area under the power and torque curves in all of the scenarios.