i was going through old mags, was reading mustang mail in the 1994 mustangs and fast fords magazine, this guy with a 1986 gt with 100,000 miles telling about how he got his in the low 12s, have any of you guys went this way? here it is,,, gt-40 heads, upper and lower intake, a 65 mm. throttle body, a m75mm. bullet sensor, svo 24-lb. injectors, svo 1.72 rollers, e-303 cam, full 2 and a half mac. exhaust with 2-chamber flowmaster, 3.73 gears. if this sounds right i should be able to do mine this way, thanks.
1986 gt, a few ?s
- Thread starter bobwb
- Start date
Stock 86 bottom end won't accept GT40 heads without notching the pistons. 86s did not come with notched pistons like any other 5.0 did.
Twisted wedge heads will fit and are better heads anyway.
Twisted wedge heads will fit and are better heads anyway.
Kdubslugga
Active Member
That setup would not run low 12s unless you have some serious suspension mods and are a very good driver!
skunk21
Active Member
+1 the larger valves one the GT40 heads are going to hit, even if you wanted to try and clay it for ptv at that point go with the TW heads because chances are real high you are going to have to cut reliefs in the pistons.
faststang90
10 Year Member
my friends old car had about the same set up and i think a low 12 is what it ran. he had the heads ported. it was a 331 ci. i dont think a stock motor with gt-40 will run a low 12. my old motor was a 306 with canfield fully ported heads, system max intake,30# inj, custom cam,and the fastest i got was a 12.18 on motor
skunk21
Active Member
25th's car runs in the 12's but I'm pretty sure not low 12's. The combo listed in here break into 12's but might be tough to get down low.
faststang90
10 Year Member
Mid/low 12s with that would be possible, providing it was a stick car and you knew what the hell you were doing, which includes all the proper supporting mods and not missing any details. I think running a letter cam is "missing a detail" but that's just me. 
25ths car runs mid 12s.
25ths car runs mid 12s.
25thmustang
Mustang Master
Mines been mid 12s, but I have a stock cam, unported E7s (GT40 valves and a valve job), stock T5, 17" ET Streets out back and 18" Bullitts out front. Honestly, with bigs and littles, suspension and a good cold day, I bet it has a 12.4, possibly a 12.3 in it. Will I ever find out... who knows? LOL
My brothers 86 has been 11.7 @ 115 with unported GT40Ps (milled, VJ and GT40 valves), cam, suspension, Cobra intake, TB, MAF and all the bolt on goodies.
Back when it was a stock cammed 3.55 geared car that we drove all winter (studded snows) it was going 12.0-12.1 @ 110.
Your average GT40 car, B cam, bolt ons, tires and driving is a mid 12s car all day. Low 12s takes some fine tuning. If your looking to bolt on low 12s, look elsewhere. If your looking to "make" the combo run low 12s, it has the potential.
My brothers 86 has been 11.7 @ 115 with unported GT40Ps (milled, VJ and GT40 valves), cam, suspension, Cobra intake, TB, MAF and all the bolt on goodies.
Back when it was a stock cammed 3.55 geared car that we drove all winter (studded snows) it was going 12.0-12.1 @ 110.
Your average GT40 car, B cam, bolt ons, tires and driving is a mid 12s car all day. Low 12s takes some fine tuning. If your looking to bolt on low 12s, look elsewhere. If your looking to "make" the combo run low 12s, it has the potential.
i don't see it as possible without serious weight reduction or short gears with good traction.my 347 with c4, 3.27 gears, afr165 heads, xe282hr cam, truck lower with sheetmetal upper, megasquirt and heavy ass capri ran mid 12's @114. i was hitting over 80 duty cycle on 30# injectors.
as i got over making this car faster i built a drag only car and tamed down the capri a little. i threw a 5 speed in it and a e 303 cam w 1.7rr it was a midrange torque mosnter i never got it to the track with this intake, i changed it because it ran like crap at light loads. i then bought a professional products intake and lightly massaged it. i lost 800 rpm of torque with it but it is more mannered.
as it is now it runs low 13 @108 taking it easy in first gear on street tires. i can beat stock ls1 vetts at the track with it and get over 20mpg.
as i got over making this car faster i built a drag only car and tamed down the capri a little. i threw a 5 speed in it and a e 303 cam w 1.7rr it was a midrange torque mosnter i never got it to the track with this intake, i changed it because it ran like crap at light loads. i then bought a professional products intake and lightly massaged it. i lost 800 rpm of torque with it but it is more mannered.
as it is now it runs low 13 @108 taking it easy in first gear on street tires. i can beat stock ls1 vetts at the track with it and get over 20mpg.
My coupe had GT40P cobra upper/lower port&polished,accufab throttle body not sure what cam long tubes 19# injectors 3550 TKO the previous got a best of 12.2 my best was a 12.8 i would say mid 12's would be possible?Some of you on here must be hell of drivers,or i must just suck??????????? peace
john
john
25thmustang
Mustang Master
Traction is a must. My car will go 12.5s -12.6s on a good tire. With street radials it's a 12.9-13.0 car. More or less half a second difference. The faster your car is, the larger that gap will potentially be. I always assume traction and a good driver when giving my opinion on how fast a car "can", "could" or "should" go.
