67mustang302

Yeah, if the carb ain't set up right, especially the accelerator pump, it'll suck harcore off the line, and can suck the whole way down the track too if the jetting is wrong.

And with my 3.00 gear I can launch at 4,000+rpm and slip the clutch, and if I let out too soon it'll bog....on street tires, on the street. Tall geared cars can be a real pia to launch.

Take the car out and just roll down the street with it in gear and drop the hammer at various rpms/gears and see what it does. If it bogs when you nail it in gear then it's prolly a tuning issue.

kalli

look at the good side of things. your car is quicker than mine ... :-)

wrenchturner75

sounds to me like a 14 second ride, with the setup you have, listen to the guys and change your gear to at least a 3:55 or a 3:80 even the car will act completely different. plus i cant see 400 plus hp on your combo, maybe 3-350 hp with a good tune. the p heads are only slightly better than the e7te. you have more cam than you can use with those heads. its all in proper part selection. p heads can be made much better with porting but if their stock then there a bottleneck. you have a high performance intake and cam but not heads. gears and a good set of heads will really wake your car up. by the way keep the converter, with the gear change youll love it!

SalikDDD

another main reason i'm mad is due that my older car (92 LX) weighing in around the same if not heavier with a similar setup, only it was EFI with P heads was running mid 13's @ 101-102 on STREET TIRES. so that's quite lame, and also my 98 GT with WAYYYY less hp and a fatter weight is a 14 FLAT with it's automatic. the car should have in the neighborhood of 275-280 to the wheels as my older LX did like i said the only difference being it was EFI

as of right now i got 64's back in the front and 71's in the rear - with a blue pump cam in the #2 slot on the carb :|

ky

looks like everyone has already answered the question but ill add one thing.

the gt40 heads are a POS.

SalikDDD

can't be too crappy if they propelled my old fox in the 13's and plenty of others in the low 13's high 12's unported, so.. i don't know. it's a combination of bad timing and crap carb i'm guessing.

Starfury

GT40P heads are great as long as you've got headers that work with them. They're essentially 351W port castings, and the P heads haveturbo-swirl chambers (hence the altered plug angle) to allow you to runless advance with higher compression. They're not as good as aftermarket heads, but they're a big step up from the original heads.

67mustang302

GT40 heads are pretty decent, especially for a stock head, but yeah they are a far cry from an aftermarket head.

Ditch that blue cam though. With your setup metering shouldn't take forever to come in and it's not a huge fuel consumer. The blue cam delivers the most amount of fuel for the 30cc pump setup and it delivers it all really fast. It's basically for a setup that needs a LOT of fuel very quickly before the metering comes in, without needing the monster 50cc setup. I can almost garuntee you that part of the bogging issue at least is that pump cam. You're dumping way too much fuel with that shot and then prolly cleaning the intake out for the first 100-200ft down the track. What squirter size do you have? And does the car bog and then go? Or go-bog-go?

Just for comparison, my setup(is totally different so it's gonna have a different cam/squirter requirement) is AFR 165's with a Crane roller cam, so it's moving more air than your setup and will need a larger initial shot(generally speaking), but it's also a 570cfm carb so metering comes in fast(and helps to reduce the size of the shot I need). I'm running the .035" squirter with the pink cam(which is the smallest fuel delivery cam along with the black cam) and it's a beast as far as throttle response. If I use the blue cam, it dumps so much fuel that the engine stalls out so hard it almost throws me through the windshield.

If it just bogs and then eventually goes try a smaller cam like the red/pink/black and go from there. If it does a go-bog-go or something similar, it's gonna need a squirter change as well, or the ignition timing is off. Also keep in mind that when you change jets on the Holleys, you have to pull UP on the float bowl/metering block when you reattach it, cuz if you don't the spring/screw on the pump curcuit linkage won't compress enough and will end up absorbing too much energy instead of transfering it to the pump and will mess up fuel delivery of the accelerator pump. Also is it vac secondary? What spring is in the diaphragm? A tall geared car will need a stiffer spring. If the spring is too soft that can cause a bog as well.

davesanborn

Wow....

I hate to burst your bubble, but you're probably much closer to 220-230HP at the CRANKSHAFT. Your automatic is sucking at least another 20% of this, putting your rear wheel HP below 200.... and this is being kind. You're drag racing a slightly modified '98 Explorer engine.Adding the headers and carb is good, but still leaves the restrictive heads in place. All three pieces of the puzzle are needed to make power. Take the GT40P's off and place them in the trunk for an increase in traction. Bolt on a set of breathing AL heads and a 150 shot'll get you into the high 11's.

The 3.08 is only a couple gearsets away from "highway" gears (2.79). 3.50's would be better suited for a strip car.

Are you on a peg leg or locked up?

Good Luck!
Dave

SalikDDD

heh my old EFI setup in my stang was an automatic / c4 also (not an AOD) also as the car started life as a 4 cyl. i dynoed 273 rwhp with that car almost 2 years ago so.. that's where i'm basing that off of. i have considered the EFI swap but i'd rather not get into the electronics with it again.

3.08 locker from a 89 SSP mustang - already have the 3.73 ring and pinion so that's what i'm going with.