The Wacos Kid

Hello all!

I am new to the mustang world and just bought a 1990 fox body 5.0. Listed below are the mods that have been made. Currently it has 2.73 gears so I am hoping to get 4.10s. It is a manual and needs a dyno tune because I timed it by ear myself.

302 that is punched .30 over with all new internal and some external parts. New parts include: Cast iron gt40 heads, Ford Racing (Pistons, E303 cam, lifters, push rods, 32 pound fuel injectors, valve covers), Scorpion 1.72 rocker arms, Summit Racing (Gear drive, high flow oil pump, lower intake, EGR valve, 75mm throttle body, 1 in. intake manifold spacer, high flow fuel pump), Trick Flow RS (Race Series) 75mm upper intake, BBK (Mass air sensor matched to 75mm throttle body, shorty headers, off road H-Pipe with 40 series Flowmaster single chamber mufflers turned down at center of car).

Driving the car, it honestly seems like a turd. But with all that it should have some more juice to it...

Thank you for the help!

VistaBlueFrank68

Check plugs for additive build-up, coil over plugs? old?, filter dirty, bad tune and 2.73 is a dog but good on gas.

pedalhappy

lol 4.10s will make it a monster in that case. Heads would make a big difference too cause gt40s are poor mans upgrades lol. which is why i still only have gt40 intake but it seems the injectors are quite a bit too big for the set up because i dont think you will see over 270 rwhp with that setup. 24# injectors would be good and a tune would prolly get you about 270ish+ but it will still feel like a turd cause the gears.

Strokednforged

I agree injectors way to big for that set up. Down size a bit! Try a good octain boost occasionally too? I use 108 it comes in the boost n the actuall race 108,can pick bottle up at autozone, n def def go with 373 or lower (meaning higher gearing) b surprised at changed in hp feal!!!

Strokednforged

Run some 108 three tank,do the gears I suggest a set ofm373's but 410'411 b a ok as well. Def downsize injectors as yer jus wasting fuel with too big of injectors !

mjr46

INJ'S are fine, dang the misinfo runs rampant in this thread, he is not wasting fuel, the fuel system on his car is a return style system = excess back to the tank, the efi controls inj pulse based on lean/rich needs or not, having 32's won't hurt the car, and what is 108??? hope it's just an inj cleaner and not 108 octane.......if so, now that'd be a real waste of money/fuel

mjr46

well get a timing light and set it to 12-14 max/base with spout out and run premium fuel after bumping timing, no such thing as timing by ear and getting it right.

dawson1112

The injectors are not to big , ecm will look at 02s maf and air temps if its to rich it will shorten pulse width . So instead of being at say .. 80 percent duty cycle the injectors will run at maybe 60 pecent duty cycle . With that set up I wouldn't expect them to be running much over 50 or 60% which leave about 25 to 35 % duty to play with later on if you decide to start adding more power to it. Don't waste your money on that 108 octane stuff they sell at autozone , instead take that 5 bucks to subway and get a sandwich it will give you more energy that the 108 will give your car. Your car feels like a turd because someone went to the trouble of doing the work to the motor first instead of upping the gear ratio first. Gear it time it drive it.... and if you can get some longtubes on those heads , The car will wake up with a shot of adrenalin like you wouldn't believe.

dawson1112

oh and notice that the one guy who gave you any good info is right above me did not " estimate your HP " , because he knows it cant be estimated. 200 250 300 ?? who knows what it is?

mjr46

that's because the only true number I believe will be close will be actually taking it to a dyno