BCisme

finally got the heads in!! on her 6th run, she thumped out 301 to the wheels running hot and spit some coolant on the dyno. stock injectors and a MAF problem held her back as well. couldn't get a final torque reading, should be about 310-315 at 4200, but the dyno decided to stop reading my torque after i hit 305 on my 4th run. have yet to take her to the track, she's down right now with a broken crank pulley. hopefully she'll see some track time before september is up. gonna try to run her on radials, as street tires ain't gonna work.

jdaniel

What kind of heads did you get and what was done to them? Im thinking of porting mine but thats gonna run me like $2000. Dunno yet.

BCisme

they are PI heads off an 01 GT. i had them ported, 210.170 oversize valves and comp cams. the works. cost me too damn much.

2000GT4.6

Aren't pre 99 engines with the PI headswap supposed to develop more power than a 99 with the same bolt ons?

I would really hope with a set of cams I would be putting numbers down close to if not identical to your numbers, and that is with no head work. I also saw a 98 with a headswap and cams only post a 281 RWHP.

I have been promised 280 RWHP with my upcoming tune (from a untuned 263 RWHP and 12.1:1 A/F ratio)

Does the head work really do alot? In any case thouse are some nice numbers.

stonemonk9

well lets see, i thought the heads were good for about 50rwhp, cams 20, and so say 225 along w/ ur other mods plus jus guestimating that 70 wuld put ya at 290 and sounds right to me?

BCisme

a non pi (96-98) motor benefits from a PI head swap with increased compression. the PI heads have a smaller combustion chamber, wich on a pre 99 block increases compression to about 10.5 to 1, as the 99+ are 9.4 to 1.i broke 300 because the heads are ported with oversize valves, the cams of course and i have alot of bolt ons. upper intake, TB, L/T headers etc.... if i had thrown in a set of 24lb injectors and the motor been a bit cooler, she would have done at least 310. i intend to add those along with a few more items to up it, if i don't put a new shortblock in it first.

2000GT4.6, with a good set of cams, like VT stage II, most 99+ guys are hitting 280-290 on the stock heads. with full bolt ons and a good tune of course. the most i've ever seen in an N/A 2V displacing 4.6 cid is 334. and he runs 11.3's.

mdvaldosta

1 point increase in compression is only worth about 2% more power, so in your case about 6 rwhp. Your #'s are nice, that was dynojet #'s I assume? And 300 rwhp is attainable with stock PI heads, full bolt-ons and cams on any 4.6 GT.

jdaniel

Yeah, you can see my bolt on's below and without a proper tune, on a hot engine and a 110% humidity I averaged out 276 rwhp on the dynojet. Im sure if I have the heads ported and bigger valves put in with a set of new cans I will be well over three hunderd.

mdvaldosta

cams alone will put you over 300 jd, something like VT stage 1's would be best with your stock heads and would add 25-30 rwhp after you got them tuned.

04mustang

ahhh it would be nice to have the money to do all that. huuuuum maybe someday.