trying to get my challenger into the 12s

[youngunss1987]

so i am wounding what my 74 challenger may do in the 1/4 mile i would like to get in the 12s i have a 340 .30 over with a voodoo cam .494 lift,eddy heads 63cc with a air gap intake,650dp carb 3.23 posi, headmen headers 904 sift kit 2200rmp stall, the car is down to around 3000lbs. should i go with a 750dp carb ? and change my gears? http://www.forebodiesonly.com/forum/picture.php?albumid=144&pictureid=799

 

[moparleo]

Gears, possibly rejetting, and more timing. What has your 60 ft. times been ?

 

[youngunss1987]

well i ran a 13.90 when my 340 was bone stock but now i have no idea or what my 60ft times are i was just hoping with this combo i could get into the 12s

 

[youngunss1987]

i was hoping to get into the 12 with a 3.23 if possible

 

[challenger6pak]

I would say use the 750 carb. You can play with tire height also. Run a low overall diameter tire for the track. It will be the same as going to a 3:55 gear without changing the gear. Mopar performance used to have tuning tips in their engine books. They may help you. Is the posted stall one you found from checking the stall or is it the advertised stall?

 

[youngunss1987]

yea i am running 15 245 60 bf goodrich tires but maybe i could go down to a 235 tire is a half inch shorter then the 245 tire and i am going to look into a 750dp proform carb

 

[Chryco Psycho]

This is my 2 cents ,You seem to have a good combination of parts .
I would start tuning , set the timing with 14-16* at idle & 36-38* at 3000 rpm , disconnect the vacuum advance , get the jetting dialed in . The engine is only an air pump so air flow in & out & heat are what make power , cold air unrestricted in & getting the exhaust out will make power , how high are you revving the engine ? Going to a 750 Proform is a good call as they are far more tunable but from an air flow standpoint you may gain very little power . The $$ may be better spent elsewhere .
Porting the heads , helps when done properly . Are you running a 180* T stat , you should be , what about a clutch fan to reduce drag ?
To me BFG & traction are opposite one can one or the other but not both !! Try a set of Nitto 555 drag radials , clamp the front of the leaf springs with flat top U bolts to make the front section as stiff as possible , lighten the front end move the battery to the back , use a 70/30 shock in front to allow the front end to rise faster , use lightweight wheels & alum driveshaft , anything that has to be turned up to speed is 10 x the value of just removing weight so 1 lb of wheel weight is = to 10 lbs removed from the car .
Take it back to the track & find out how close you are .

 

[youngunss1987]

i am looking into a electric fan right now and i just got some fenton aluminum slot rims vs the steel ones i had and i am thinking that the 750 proform with work out for me i am just waiting to get my eddy heads back from the shop i got them ported ! and i am not looking to turn my 340 passed 6000rpm but this summer i am taking it to the track my goal is to have a very stock appearing challenger that will run 12s

 

[Chryco Psycho]

I doubt the eletric fan will work very well , most electrics cannot move enough air to keep an engine cool properly , I still recommend the Clutch fan as best choice .

 

[cudajoe13]

An aluminum drive shaft cost can be better used elsewhere. The small diameter makes the rotaional inertia inconsequential. Same with axles. Wheels are a different story. Fans only work for you under 30 mph. So, with a shroud on an electric fan with a big enough radiator, maybe even an electric water pump (they run full speed even at idle), I don't see an overheating problem. Still, lower rearend gears could be well worth it. Don't hear of many 3.55's busting 12's.
Just my penny & a half.

 

[DukeBoy]

What is your goal?? 12.99 99/100?

Or DEEP in the 12's? Like 12.40's?

Gonna need alotta engine with a small block to achieve that. Either that, or some hellacious gears. Maybe some, how you youngin's say it now? NOS? (Pronounced Knoss instead of N...O....S).

 

[sluvxe]

What is your goal?? 12.99 99/100?

Or DEEP in the 12's? Like 12.40's?

Gonna need alotta engine with a small block to achieve that. Either that, or some hellacious gears. Maybe some, how you youngin's say it now? NOS? (Pronounced Knoss instead of N...O....S).

Nitrous isnt too great if you are trying to save money, since you will be rebuilding often, assuming you dont blow up the motor.

 

[Juan Veldez]

Nitrous is the cheapest horsepower gain. Someone tell me how else you can drop 2 seconds off your ET by spending around a grand? Now that assumes your starting in the 14 second range, not already running 8's. As I tell everyone, get a nitrous kit with a programmable controller and don't abuse it by spraying it too hard and your drive train will be fine if not already worn out (obviously). It's just like any other horsepower upgrade, if you get crazy, parts will fly. And the beauty with NOS is that your only stressing parts when you spray it. Just normal driving down the highway and it's just normal stress, instead of full time with a high lift, long duration cam, big carb sucking gas, etc.. Talk to a professional in your neighborhood that has experience with NOS. And yes DukeBoy, it bugs me too when the young pokes say it "knaws"! Dang that fast and the furious movie!

 

[DukeBoy]

Been running "Knoss" for over 25 years....NEVER "Blown" and engine using it. of course, this doesn't mean diddly to the "Beginner" user, but N20 doesn't blow engines, ignorant, impatient, and generally agressive driver's with heavy right foots blow engines on N20.

 

[youngunss1987]

well i wanted to do this on all motor and not use any spray my 340 will makes round 450 hp after the porting on the dyno i am looking to go with a 750 carb and maybe msd and put the motor back in the car i feel that the will make a strong run given that its only 3065lbs with me in it and i would be happy with 12.99 run when the car was stock it ran a 13.90s but that was with stock heads exhaust intake and with a open differential

 

[moparleo]

How did you get rid of that much weight ?

 

[youngunss1987]

well i took the a/c off and spare tire, got rid of those steel rims and add aluminum ones, took the heads and intake off and added alumimum heads and intake along with a aluminum drive shaft then top it off with a rebuilt 904 trans which is lighter then the 727

 

[youngunss1987]

the edelbrock 60779 were 30lbs each not sure what stock ones were
edelbrock air gap intake was 19lbs i believe the stock one was round 60lbs
the drive shaft was 35% lighter then stock and i would love to know the weight difference between the 904 and 727 but the 727 seem a lot heavier then 904 when i pulled it out and the same goes for the rims spare tire had to have been 50 or 60lbs and the a/c all together had to have been 100lbs

 

[burntorange70]

Have you been to the track with the new set up? If it was me I would tune/dial in what you have and go to the track for some base line numbers.


A stock SB E body is what? 3400LB or so I would say. I don't think you dropped 500LB with the mods you did. Only way to know for sure though is to put it on a scale.

 

[moparleo]

My thoughts exactly.