EFIDynoTuning Forum

I recently purchased a heavily modified 99 GT Mustang. Prior I had very limited knowledge with cars in general and this was more a hobby / learning experience purchase. Car was previously tuned with SCT x4 and supposedly 600rwhp. I purchased a quarterhorse and pulled the current tune which will be attached here for review. The modifications listed below are to the best of my knowledge but certain things I have not been able to 100% verify at this time.

Engine
MMR 4.75l 1000SE stroker rotating assembly (in a teksid block I believe.)
9:5.1 Compression ratio
4V Cobra heads split Port / polish
98 Cobra intake manifold
1° colder plugs gapped at .22-24 thousandth
Unknown camshaft
Open breathers on valve covers I deleted and ran -10an lines to a catch can with breather.

Fuel System
93 Octane E10
55lb injectors
Bosch 44 300 lph in-line pump
Aeromotive regulator (30-35 psi at idle)

Exhaust
BBK long tube headers
O/R H pipe
Borla S type mufflers

Supercharger
Vortech V1 T-trim
Air to liquid intercooler
Set at 12 psi boost
3.33 pulley

T-56 Transmission
3.73 rear end gears

Suspension and tires
Car lowered about 2.5"
Adjustable coil overs
Kenny Brown tubular k member and control arms
Kenny Brown rear UCA and LCA
265/35/18 front
315/30/18 rear

are they b heads or c heads?? that makes a huge difference

decipha wrote: ↑2024 Sep 17, 20:45 are they b heads or c heads?? that makes a huge difference

I wish I knew lol.. any ideas how I can tell or how much I need to start tearing down to figure it out?

Edit** I spoke with previous owner and he thinks 2004, so that would be C heads until I verify.

look at the casting stamp on the head

your injectors are clipped and not dialed in, your maf isn't dialed in, spark isn't dialed in

probably best to just start over

That's fine with me. Whatever needs to be done to get it right.

I checked the casting and there's a 95 stamped on each head so looks like B's is where we're at.

yeah, if your not comfy dialing her in its prob best to go the remote route. http://www.efidynotuning.com/remote.htm

thats only if you have issues? hows she run?

Car was running fine as far as I could tell no cel. When I first bought it I had O2 sensor issues. The transmission had just been rebuilt and the shop plugged the wiring harnesses into the wrong sensors. Clutch is still new so Ive just been babying it. I actually had it down for about a month replacing ball joints and motor mounts. I started it up Sunday, and at first she fired up then bogged down and died. Then she was just cranking but not firing so I waited a few mins and she fired up. I drove her for about 20 mins and did 2 quick WOT pulls from 2nd to 4th (which I regret a little now lol). Took her to a park and she sat for maybe 30 mins. Fired up right away and drove her home where she's sat since.

I tried to fire her up this evening and she's just cranking but won't fire. I had to leave for an event tonight so I left it at that. Not sure if its a fuel or spark issue. The fuel pressure gauge is pegged at 38 psi when I turn the key on. I can hear the inline pump running. I was told the plugs were replaced before I bought it but I have not pulled them out yet. I guess it's a good idea to check them when I get a chance.

I plan on upgrading the fuel system and converting to E85. Maybe losing the inline and dropping a bigger pump in the tank with 96 injectors and new fuel lines. I don't know if it's worth dialing in the tune now I really just want to make sure it's tuned well enough to not give me issues until I upgrade the fuel system. Maybe I'll get on the fuel system sooner than later. No matter what I do I would definitely go the remote tuning route because this is all new for me and I honestly don't even know where to start.