I went out looking for a tuner this weekend and ended up buying the Diablosport Predator. I drove down to Summit Racing again this weekend to look at tuners. They had two for the Mustang GT. The Diablo that I ended up buying and the Granatelli Fuego Flash Tuner. The thing that I did like about the Granatelli was the fact that you can use it on up to six Ford vehicles and their website said it will datalog. Well, after doing some research on the web I had seen nothing but negative reviews about that tuner. To sum up what I had read was this gem of a quote: " DON'T WASTE YOUR MONEY ON GMS.. That tuner is craptastic.." So after looking at both, I will have to say that the build quality was better on the Diablo. It was a little more money and you can only use it for one vehicle, but most of the reviews I had read online were positive. Plus there are two shops that are close by that will make custom tunes once I have an engine that is modified enough to warrant a dyno tune.
I am aware of another quality tuner out there for the Mustangs and that would be the SCT SF3 Power Flash. I have also heard nothing but good things about SCT, but while reading their manual I came across this: "X3 Power Flash VIN locks to a single vehicle. You cannot use the device to tune a new or different vehicle, until you have returned the original vehicle back to stock, which will unlock the device. You can only change vehicles 5 times before the unit is permanently locked." With the Diablo tuner you can change to any number of vehicles, you just have to put back the stock program before you move on to another vehicle. That right there knocked SCT out of the running for me. Now it looks like the new SCT LiveWire tuner does not have the 5 vehicle limit, but it is way out of my price range.
After I got it home, I went to The Diablo website and downloaded the software and the updates for this tuner. The instructions were great and the process was painless. Another neat feature is using this hand held tuner to do 'check engine' diagnostics. It reads the fault codes from your OBDII port and if your 'check engine' light is on it will list the fault codes with explanations. After you read those fault codes then you can clear them and turn off the 'check engine' light. My check engine light has been coming on every now and then and by checking the codes they are more from the light mods I have on my car (cat back FlowMasters and K&N cold air induction). A custom tune will take care of these.
After I cleared my fault codes I went for a drive so I could burn up some of the last bits of gas I had in my tank. I know, it's tough to HAVE to drive your car around burning up gas! The reason to empty the tank was so I could fill it with 93 octane fuel. The Diablo Performance tune requires 93 octane. I filled up the tank and headed home to flash the computer with the Diablo Performance tune. This took maybe 5 minutes tops and was very easy because of the excellent menu on the tuner. After it was done, I unhooked the tuner from the OBDII port and fired up the GT. As soon as I hit the street I could tell a difference on how my Mustang now accelerates, it has more power lower in the RPM range. When I took it on the freeway ramp and stomped on it, there was a noticeable difference on how hard the car pulled down the ramp. I was all smiles!
I'm very happy with this tuner. I have just scratched the surface on what it can do, but for now it has helped my project car move down the road a little faster. As I add more mods I'll be able to use it to upgrade my tune to keep up with my modifications. Another good weekend upgrade!
Oh, I'm still waiting on the Steeda underdrive pulleys. Called Mustangs Unlimited and they said that the order should be in by the 10th of June.